RSBO v.12 - n.01

v. 12 – n. 1 – January/March 2015

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ISSN: Electronic version: 1984-5685

RSBO

Joinville – SC

v. 12

n. 1

135 p.

2015

Rector Sandra Aparecida Furlan Vice-Rector Alexandre Cidral Dean for Education Sirlei de Souza Dean for Research and Post-Graduation Denise Abatti Kasper Silva Dean for Extension and Community Affairs Claiton Emilio do Amaral Dean for Administration Cleiton Vaz Editorial Production Editora UNIVILLE Luciana Lourenço Ribeiro Vitor – Text revision and translation e-mail: llribeiro_3@hotmail.com Raphael Schmitz – Graphic design Marisa Kanzler Aguayo – Diagramming EDITORIAL BOARD Editor-in-chief Flares Baratto-Filho – Univille and UP, Brazil Administration Editors Fabricio Scaini – Univille, Brazil Luiz Carlos Machado Miguel – Univille, Brazil Carla Castiglia Gonzaga – UP, Brazil Tatiana Miranda Deliberador – UP, Brazil Associate Editors Edson Alves de Campos – Unesp, Brazil Sandra Rivera Fidel – Uerj, Brazil Gisele Maria Correr Nolasco – UP, Brazil Luiz Fernando Fariniuk – PUC/PR, Brazil Kathleen Neiva – University of Florida, USA Claudia Brizuela – University of Andes, Chile Johannes Ebert – University of Erlangen, Germany Nicolas Castrillon – University São Francisco of Quito, Ecuador

Editorial Board Alessandro Leite Cavalcanti – UEPB, Brazil Carlos Estrela – UFG, Brazil Christoph Kaaden – University of Munich, Germany Fernanda Pappen – UFPel, Brazil Fernando Branco Barletta – Ulbra, Brazil Fernando Goldberg – University of Salvador, Argentine Frank Lippert – Indiana University, USA Guilherme Carpena Lopes – UFSC, Brazil Jesus Djalma Pécora – Forp/USP, Brazil José Antônio Poli de Figueiredo – PUC/RS, Brazil José Carlos Laborde – Catholic University of Uruguay, Uruguay José Luiz Lage-Marques – USP, Brazil José Mondelli – FOB/USP, Brazil Juan Carlos Pontons-Melo – Sao Marcos University, Peru Lourenço Correr Sobrinho – FOP/Unicamp, Brazil Lúcia Helena Cevidanes – University of North Carolyn at Chapel Hill, USA Luciana Shaddox – University of Florida, USA Luis Sensi – University of Florida, USA Luiz Narciso Baratieri – UFSC, Brazil Manoel Damião Sousa-Neto – Forp/USP, Brazil Marco C. Bottino – Indiana University, USA M a r í a Merc e de s A z uer – Javer i a n a Un i versit y, Colombia Mário Tanomaru Filho – Unesp, Brazil Miguel González Rodríguez – Odonthos Institute, Dominican Republic Mu ha nad Hat a m leh – Un iversit y of Ma nchester, England Osmir Batista de Oliveira Júnior – Unesp, Brazil Pedro Bullon Fernandez – University of Sevilha, Spain Regina M. Puppin-Rontani – FOP/Unicamp, Brazil Richard L. Gregory – Indiana University, USA Rivail Antônio Sérgio Fidel – Uerj, Brazil Rodrigo Neiva – University of Florida, USA Sandra Milena Brinez Rodriguez – Javeriana University, Colombia Saulo Geraldeli – University of Florida, USA Ulrich Lohbauer – University of Erlangen, Germany Valentina Ulver de Beluatti – University of Maimonides, Argentine Valeria Gordan – University of Florida, USA Yara Teresinha Corrêa Silva Sousa – Unaerp, Brazil

The content of the articles is of sole responsibility of the authors.

Table of Contents Guest editorial.................................................................................................................................................... 6

Original Research Articles Shear bond strength of brackets bonded with nanofilled flowable resins........................................................... 8 Danielle Rodrigues Morais, Alexa Helena Köhler Moresca, Estela Maris Losso, Alexandre Moro, Ricardo Cesar Moresca, Gisele Maria Correr

Effect of dentin desensitizers on resin cement bond strengths......................................................................... 14 Rubens Nazareno Garcia, Marcelo Giannini, Tomohiro Takagaki, Takaaki Sato, Naoko Matsui, Toru Nikaido, Junji Tagami

Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion................ 23 Tiago André Fontoura de Melo, Cíntia Muniz Couto

Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation.......................... 32 Simone Scandiuzzi Francisco, Adriana de Jesus Soares, Rodrigo Dutra Murrer

Assessment of knowledge about oral cancer: study with students of public education.................................... 41 Iara Fiorentin Comunello, Elisabete Rabaldo Bottan, Constanza Marín, Eduardo Mazzetti Subtil

Evaluating of oral and salivary conditions of two specific groups of workers................................................... 50 Nicolae Carvalho de Paula, Carolina Dea Bruzamolin, Paulo H. Tomazinho, Luciane Variani Pizzatto, Wellington M. Zaitter, Eduardo Pizzatto

Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials......... 56 Kiany Scarssi Nunes, Luiza Bonezi Boff, Juliana Royer, Tiago André Fontoura de Melo

Linear setting expansion of different gypsum products................................................................................... 61 César Antunes de Freitas, Tatiana Sanches Zanotti, Fabio Antonio Piola Rizzante, Adilson Yoshio Furuse, Márcia Furtado Antunes de Freitas

Literature Review Articles Developmental anomalies affecting the morphology of teeth – a review.......................................................... 68 Ashish Shrestha, Vinay Marla, Sushmita Shrestha, Iccha K Maharjan

Indications and restorative techniques for glass ionomer cement.................................................................... 79 Fabio Antonio Piola Rizzante, Rafael Schlögel Cunali, Juliana Fraga Soares Bombonatti, Gisele Maria Correr, Carla Castiglia Gonzaga, Adilson Yoshio Furuse

Application of BMP-2 for bone graft in Dentistry.............................................................................................. 88 Lídia Audrey Rocha Valadas Marques, Edvan Alves da Costa Júnior, Mara Assef Leitão Lotif, Edilson Martins Rodrigues Neto, Francisco Filipe Carvalho da Silva, Carlos Ricardo de Queiroz Martiniano

Case Report Articles Mesiodens surgery at deciduous and permanent dentition.............................................................................. 94

Mariana Dalledone, Paulo Afonso Tassi-Junior, Juliana Feltrin de Souza, Estela Maris Losso

Compound odontoma associated with dentigerous cyst in the anterior mandible – case report....................... 98 Radamés Bezerra Melo, Yuri Edward de Souza Damasceno, Celio Armando Couto da Cunha Junior, Igor Vasconcelos Pontes

Free gingival graft to increase gingival dimensions in Down syndrome patients: clinical case report............. 103 Carla Hariene Montanha, Maria Estela Plens, Henrique Scheffer Ferreira, Luiz Augusto Ribas, Vinicius Augusto Tramontina, João Armando Brancher, Andréa Paula Fregoneze

PROCEEDINGS OF THE 3rd ICOI-BRAZIL 2014 – INTERNATIONAL CONGRESS OF ORAL IMPLANTOLOGY Research Studies Evaluation of cranial bone repair in experimental model treated with bisphosphonates. Histological and hystometric study in rabbits........................................................................................................................... 109 Juliana de Sousa Vieira, Isabela Gohringer, Emanuelle Cunha, Allan Fernando Giovanini, João César Zielak, Tatiana Miranda Deliberador

Osteocalcin immunoprofile assessment on bone repair in critical size defects treated with white subcutaneous adiposetissue in rat and rabbit animal model...........................................................................110 Tadeu Vieira Barros, Caroline Moreira Auersvald, Letícia de Souza Moraes, Tatiana Miranda Deliberador, Lucienne Miranda Ulbrich, Thalyta Verbicaro

Evaluation of hard palate tomographic regions for skeletal anchorage devices installation............................. 111 Giovani Lago, Mauro Toma, Ricardo Lima Navarro, Ana Cláudia de Castro Ferreira Conti, Paula Vanessa Pedron Oltramari Navarro, Thais Maria Freire Fernandes

Histological and histomorphometric evaluation of low laser therapy (LLT) and platelet rich plasma (PRP) in the process of bone repair. Experimental study in rats................................................................................ 112 Rafael Zancan, Lucas Oliveira Azevedo, Ana Claudia Fonseca, Thiago Jonasson, Marcela Claudino da Silva, Allan Fernando Giovanini, Melissa Rodrigues de Araujo

Comparative study between the digital and conventional radiography in the process of bone repair with low-level laser therapy (LLLT) and platelet-rich plasma (PRP)............................................................................ 113 Lucas Oliveira Azevedo, Rafael Zancan Mobile, Ana Claudia Fonseca, Thiago Jonasson, Rafaela Scariot, Allan Fernando Giovanini, Melissa Rodrigues de Araujo

Aesthetic perspective from the dental papilla evaluation in the upper anterior region....................................114

Claudia A. Pimenta, João César Zielak, Carlos Eduardo Francischone

Analysis of mandibular bone remodeling in rabbits treated with bisphosphonate................................ 115 Emanuelle Cunha, Giovanna Portela, Juliana de Sousa Vieira, João César Zielak, Tatiana Miranda Deliberador, Allan Fernando Giovanini

Immunoprofile ratio between osteocalcin (OC) and PPAR-G in PRP-induced bone repair..................................116 Giovanna Portela, Emanuelle Cunha, Juliana de Sousa Vieira, João César Zielak, Tatiana Miranda Deliberador, Allan Fernando Giovanini

Comparative study of vitamin E and C systemic action in alveolar bone remodeling of rats ...........................117 Caroline Resquetti Luppi, Gustavo Jacobucci Farah, Vinicius Denepotti Nogueira, Carolina Luppi Gonçalves, Roberto Kenji Nakamura Cuman, Wilton Mitsunari Takeshita

SEM analysis of dentaltitanium implants surface touched with surgical glove, steel tweezers, and titanium tweezers.......................................................................................................................................................... 118 Rafael Peres, Tatiana Miranda Deliberador, João César Zielak, Maria Cecília Giacomel, Allan Fernando Giovanini, Paulo Roberto Camati

Case Report Studies Aesthetic resolution of maxillary lateral incisor by implant immediate installation and prosthesis associated with lateral sliding flap.................................................................................................................................... 119 Carmen L. Mueller Storrer, Sara Moncada S., Felipe Rychuv Santos, João César Zielak, Viviane Crivellaro, Tatiana Miranda Deliberador

Correction of gingival smile without FLPA: predictability with minimum morbidity........................................ 120 Bernardo Born Passoni, Bruna Corrêa, João Gustavo Oliveira de Souza, Armando Rodrigues Lopes Pereira Neto, Ricardo de Souza Magini, César Augusto Magalhães Benfatti

Step-by-step approach of extraction sockets in areas of pneumatized maxillary sinus....................................121 Bernardo Born Passoni, João Gustavo Oliveira de Souza, Armando Rodrigues Lopes Pereira Neto, Antônio Carlos Cardoso, Ricardo de Souza Magini, César Augusto Magalhães Benfatti

Use of PDS II wire as titanium reinforced membrane substitute for guide bone regeneration techniques....... 122 Bernardo Born Passoni, Ricardo de Souza Magini, César Augusto Magalhães Benfatti

Optimization of immediate implant installation in inter-radicular septum area............................................... 123 Artur Breno Wanderley Alécio, Letícia Moro Bins Ely, Abraão Moratelli Prado, José Daniel Suárez Rodríguez, Aguedo Aragones, Ricardo de Souza Magini

Peeri-implantitis surgical treatment.................................................................................................................124 Maurício Assunção Pereira, Abraão Moratelli Prado, Haline Renata Dalago, Guenther Schuldt Filho, José Moises de Souza Júnior, Marco Aurélio Bianchini

Dream to reality – metal-ceramic total rehabilitation of maxilla supported by implant....................................125 Luciano Rosa, Nereu Roque Dartora, Paulo Renato Pulga

Atrophic mandible fracture after surgical rehabilitation with osseointegrated implants: case report.............. 126 Vinicius Fabris, Jose Luiz Cintra Junqueira, Agenor Montebello Filho, Milena Bortolotto Felippe Silva, Ariosto Ribeiro

Use of titanium miniplates as temporary skeletal anchorage in orthodontics..................................................127 Marcio Vinícius Hurczulack de Quadros, Paulo Roberto Müller

Surgical approach of a lower third molar impacted and fused with a supernumerary adjacent to the canal mandibular: case report........................................................................................................................ 128 Marcio Vinícius Hurczulack de Quadros, Arthur Berny Castellano, Paulo Roberto Müller

Oral rehabilitation with single implants in aesthetic area: case report............................................................ 129 Gabriela de Souza Zimiani, Eduardo Kurihara, Roberto Masayuki Hayacibara

Partial resection of mandible with immediate installation of TMJ total prosthesis ......................................... 130 Bento Stang, Jakson Pedro Antonelli, Álvaro Bedin, Alexandra Priester, Fabiane Frigieri, Lucely da Silva

Bone expansion simultaneous to implant installation......................................................................................131 Gabriela Mercedes Juanito Peñarrieta, Carolina Schaffer Morsch, Caroline Freitas Rafael, Juan Felipe Montero Dumez, Luiz Fernando Gil, Marco Aurélio Bianchini

Clinical solution for correction of angledimplant without aesthetic impairment..............................................132 Caroline Freitas Rafael, Cintia Schiochett, Carolina Schaffer Morsch, Camilo Villa Bona, Claudia Ângela Maziero Volpato, Antônio Carlos Cardoso

Rehabilitation of atrophic maxilla with prosthesis fixed on four implants: “all on four”...................................133 Caroline Freitas Rafael, Carolina Schaffer Morsch, Gabriela Mercedes Juanito Peñarrieta, Claudia Ângelo Maziero Volpato, Marco Aurélio Bianchini

Vertical increase in anterior maxila through the nasal cavity augmentation by biooss and bioguide.............. 134 Caroline Freitas Rafael, Clessius Ferreira Xavier, Cintia Schiochett, Carolina Schaffer Morsch, Claudia Ângelo Maziero Volpato, Marco Aurélio Bianchini

Space increase for rehabilitation in the anterior region through occlusal adjustment by addition...................135 Carolina Schaffer Morsch, Caroline Freitas Rafael, Leticia Bins Ely, Gabriella Mercedes Juanito Peñarrieta, Juan Felipe Montero Dumez, Antônio Carlos Cardoso

Guest editorial Caffeine and bone metabolism: is there any relevance to the dentist?

Bone is a dynamic tissue highly ordered with support, protection, and mobility functions of the human body, in addition to be an important mineral reservoir. Bone physiology is controlled by a complex interaction of mechanical, hormonal, circulatory, metabolic, and nutritional factors so that changes in the balance reflect in the deposition and resorption functions exerted by bone cells. The dentist and some other health professionals are daily related to the diagnosis and treatment of patients requiring interventions involving the direct or indirect handling of bone tissue, so that the knowledge of the alterations in the aforementioned factors is of paramount importance.

Caffeine, a methylxanthine widely consumed in the diet of the world population, is present in coffee, tea, soft drinks, food, medications, and dietary supplements. According to the Food and Drug Administration [9], caffeine intake in the US population reaches 300 mg person/day (approximately four espresso cups), and the largest sources are coffee, soft drinks, and teas. Despite the large consumption of caffeine, its consequences for bone metabolism are still the controversy, but studies have shown harmful effects with acute and chronic exposure to this substance, or even when associated with certain systemic physiological changes such as osteoporosis.

With the large number of dental surgical procedures such as extractions, bone reconstruction, and implant installation, which depend on adequate bone repair, is it possible that caffeine consumption by patients may alter the metabolism of the alveolar bone? In humans, there are no studies that really show/quantify a deleterious effect on the alveolar process, but in animals some interesting information can be found mainly in rats. Concerning to the repair of post-extraction tooth socket, both the daily ingestion of coffee (chronic) and intraperitoneally injected caffeine (acute) show a delay of the entire repair process, culminating with histologically immature bone tissue with volume of 40% and 60% lower than that of controls, respectively [7]. With regard to bone reconstructive procedures, the literature is still poor on the subject, only one study performed in animals relates the use of caffeine and its influence on the autogenous bone integration process, whose results demonstrated the development of foreign body inflammatory reaction on the surface of the bone fragment, leading to low capacity of osteoid matrix synthesis around the graft material [6].

The caffeine mechanisms of action on bone are not entirely clear, but have been classified as direct and indirect. The latter occurs secondary to changes in calcium and phosphorous homeostasis, caused by changes either in hormones or in the absorption and excretion regulators. Lacerda et al. [3] demonstrated that coffee chronically ingested by rats was responsible for decreasing bone mineral density, higher calcium levels in plasma, and also by its high concentration in the urine, which demonstrates the ability to mobilize bone calcium into the blood with the consequent elimination of this mineral in the urine.

The direct actions are associated with alterations in the activity of bone cells, and studies have shown changes in differentiation, proliferation, and matrix synthesis, and mineralization of osteocytes and osteoblasts. Caffeine can also modulate various aspects of inflammatory and immune adaptive/innate response, altering the concentration of mediators with important functions also in repair.

Considering osteoporosis, recent studies have reported excessive consumption of caffeine as an accelerating factor for this pathology development [8]. Concerning to the major consequence of this disease – bone fractures –, there is no consensus whether caffeine may increase the risk of such an event occurs. Systematic reviews on the subject affirm that daily coffee consumption is associated with an increased risk of fractures especially in women [4]. On the other hand, a study on Swedish women showed that long-term coffee consumption (more than four cups/day) caused a reduction in bone density between 2% and 4%, but not related to increased risk of bone fractures [2].

And regarding to the osteoporotic patients and larger consumer of beverages containing caffeine, is there any impact on bone healing? Studies on animals also show that osteoporosis associated with caffeine intake is able to increase bone loss around teeth with experimentally induced periodontal disease, reduce the area of trabecular bone around healthy teeth, and decrease post-extraction cellular

reparative capacity tooth [1]. Also, in bone repair models using dental alveoli of rats, the osteoporosis by itself is able to reduce synthesized bone volume in 40% and in the presence of caffeine this effect is exacerbated, so that the value reaches 61% compared to controls, in addition to provide the development of tiny and hypomineralized bone trabeculae [5].

It is a fact that caffeine exerts a detrimental effect on bone metabolism in general, including the alveolar bone. Therefore, the dentist must have the knowledge that bone metabolism is controlled by various endogenous and exogenous factors, including caffeine, which can have a synergistic effect with systemic physiological changes, generating a deleterious effect on the various procedures involving bone.

Many studies are still needed, both in animals and in humans, in order to establish the real alveolar bone changes, its clinical implications, and the possible safe daily limit for caffeine consumption, a substance so widespread and necessary for humans of the modern world.

References 1. Bezerra JP, de Siqueira A, Pires AG, Marques MR, Duarte PM, Bastos MF. Effects of estrogen deficiency and/or caffeine intake on alveolar bone loss, density, and healing: a study in rats. J Periodontol.

2013;84:839-49.

2. Hallström H, Wolk A, Glynn A, Michaëlsson K. Coffee, tea and caffeine consumption in relation to osteoporotic fracture risk in a cohort of Swedish women. Osteoporos Int. 2006;17:1055-64.

3. Lacerda SA, Matuoka RI, Macedo RM, Petenusci SO, Campos AA, Brentegani LG. Bone quality associated with daily intake of coffee: a biochemical, radiographic and histometric study. Braz Dent J. 2010;21:199-204.

4. Lee DR, Lee J, Rota M, Lee J, Ahn HS, Park SM et al. Coffee consumption and risk of fractures: a systematic review and dose-response meta-analysis. Bone. 2014;63:20-8.

5. Macedo RM, Brentegani LG, Lacerda SA. Effects of caffeine on bones of osteoporotic rats. Journal of Caffeine Research. 2012;2:140-5.

6. Macedo RM, Lacerda SA, Brentegani LG, Bombonato-Prado KF, Prata CA. Osteointegration of autogenous bone graft associated with osteoblastic cells under treatment with caffeine. Implant Dent.

2011;20:369-73.

7. Macedo RM, Lacerda SA, Brentegani LG. Coffee intake and intraperitoneally caffeine effects on bone repair process. Histologic and histometric study. Braz Dent J. 2015 (accepted).

8. Sanders S, Geraci SA. Osteoporosis in postmenopausal women: considerations in prevention and treatment: (women’s health series). South Med J. 2013;106:698-706.

9. Somogyi LP. Caffeine intake by the U.S. population. Food and Drug Administration; 2012.

Rander Moreira Macedo MSc, PhD in Oral Rehabilitation – Forp/USP Residency in Oral Implantology – Royal London Hospital – UK Specialist in Periodontics and Prosthodontics Adjunct Professor of Prosthodontics – Positivo University

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):8-13

Original Research Article

Shear bond strength of brackets bonded with nanofilled flowable resins Danielle Rodrigues Morais1 Alexa Helena Köhler Moresca1 Estela Maris Losso1 Alexandre Moro1 Ricardo Cesar Moresca1 Gisele Maria Correr1 Corresponding author: Gisele Maria Correr Graduate Program in Dentistry – Positivo University Rua Pedro Viriato Parigot de Souza, n. 5.300 – Campo Comprido CEP 81280-330 – Curitiba – PR – Brazil E-mail: giselenolasco@up.com.br 1

Graduate Program in Dentistry, Positivo University – Curitiba – PR – Brazil.

Received for publication: May 13, 2014. Accepted for publication: October 22, 2014.

Keywords: orthodontics; shear strength; orthodontic brackets.

Abstract Introduction and Objective: To evaluate the shear bond strength of brackets fixed with different materials (two light-cured nanofilled low-viscosity resins – Transbond Supreme LV and Flow Tain LV and two light-cured traditional resins – Transbond XT and Transbond Plus Color Change) after 10 min and 24 h, and to evaluate the type of failure. Material and methods: Eighty bovine incisors were selected and randomly divided into groups (n = 10) according to the material and fixation period. The brackets were bonded following the manufacturer's instructions and stored in deionized water at 37oC for 10 min or 24 h. After, the specimens were submitted to shear bond strength test at 0.5 mm/min and evaluated for adhesive remnant index (ARI). The data were submitted to Kruskal Wallis and Wilcoxon tests (p < 0.05) and the ARI scores to Chi-Square test. Results: There was a significant difference among the materials (p < 0.05) (after 10 min – Transbond XT > Transbond Plus Color Change > Transbond Supreme LV = Flow Tain LV and after 24 h – Transbond XT > Transbond Plus Color Change = Transbond Supreme LV =

– RSBO. 2015 Jan-Mar;12(1):8-13 Morais et al. – Shear bond strength of brackets bonded with nanofilled flowable resins

Flow Tain LV). There was no significant difference in resistance values between 10 min and 24 h, except for Transbond Plus Color Change. Most groups showed adhesive remaining adhered to the enamel (scores 2 and 3) without statistical significant difference (p > 0.05). Conclusion: The light-cured traditional resins showed higher resistance than the nanofilled materials. The period of fixation had no influence on the resistance for different materials, except for Transbond Plus Color Change.

Introduction The success of the orthodontic treatment, among other factors, is greatly influence by accurate bracket positioning and long-term retention of these accessories [3]. Failures during bracket bonding can disrupt and delay the treatment, increase the cost, and hinder a correct finalization of the case.

Frequent bracket rebonding can also cause damage to the enamel structure [28].

The use of light-cure resins in bracket bonding can be considered a standard clinical practice [24].

Advances in the bonding materials had occurred over the years, especially in their composition, aiming to share the efficient adhesion to the individual needs of the orthodontic patients. Several materials are available for bracket bonding, such as resin-modified glass-ionomers, resin composites, orthodontic adhesives, flowable resins and more recently introduced nanofilled materials [1, 11, 13, 18, 27].

The nanotechnology significantly contributed to the biomedical field, allowing the development of materials and structures with much reduced size: 0.1 to 100 nanometers. In Dentistry, the nanofilled resin composites show improved physical and mechanical properties, with higher fracture resistance and bond strength to enamel [2, 5, 15, 17, 27].

Many clinicians have been applied flowable resins in Orthodontics [1, 19, 24]. These resins have some advantages such as no stickiness and fluid injectability [9], because of their characteristics such as reduced filler content, increased diluents monomers or altered rheology. However, these characteristics may reduce the mechanical properties of these materials [23]. There are still few studies available that evaluate the bonding properties of these materials, [1, 13, 24, 26] with contradictory reports on the shear bond strength [9, 19, 26].

Combining the advantages of a flowable resin and the nanotechnology, a nanofilled low-viscosity light-cured adhesive was introduced by 3M Unitek,

Transbond Supreme LV. The adhesive contains a dimethacrylate polymer that modifies the rheology, allowing the material to flow under pressure, yet hold its shape after placement until light cured [6].

This characteristic is beneficial since the material will not slump, run, or drift from the bracket base prior to placement in the patient’s mouth.

Also, this material is a nanofilled resin that shows a reduction on filler size and increase on filler content (nanoclusters), allowing better mechanical properties [17]. However, little is known about the bonding characteristics of this material.

Another important factor is the post-fixation time that can influence the brackets bond strength and is important for the installation of the arches or accessories in the oral cavity. Thus, the aim of the present study was to evaluate the shear bond strength (SBS) of brackets fixed with different materials (two light-cured nanofilled low viscosity resins – Transbond Supreme LV and Flow Tain LV and two light-cured traditional resins – Transbond XT (control) and Transbond Plus Color Change) after 10 minutes and 24 hours. The hypothesis of this study was that there will be no difference in the SBS values among the nanofilled and traditional resins and there will be no influence of post-fixation time on SBS.

Material and methods A total of 80 sound-extracted bovine incisors were stored in a 0.5 Chloramine T solution at 4oC for a maximum of 1 month after extraction.

Teeth were randomly assigned into 8 groups (n = 10) according to the material (Transbond XT – 3M/Unitek, Transbond Plus Color Change – 3M/ Unitek, Transbond Supreme LV – 3M/Unitek and Flow Tain LV – Relience) and the post-fixation time (10 minutes or 24 hours).

The roots of the teeth were cut and discarded and the fragments of the middle third of the crowns were cut. The fragments were flattened and embedded into PVC tubes (Tigre S.A. Tubos e Conexões, Castro, PR, Brazil) using acrylic resin (Vipi Flash, Pirassununga, SP, Brazil).

For the bonding technique, the buccal enamel surface of each fragment was cleaned with fluoridefree pumice slurry, etched with 37% phosphoric acid gel (Etch-37, Bisco, Schaumburg, Ill) for 30 seconds, rinsed for 15 seconds, and dried with oilfree and moisture-free air for 20 seconds until the enamel had a faintly white appearance. After, the different materials (Transbond XT, Transbond Plus Color Change, Transbond Supreme LV and Flow

10 – RSBO. 2015 Jan-Mar;12(1):8-13 Morais et al. – Shear bond strength of brackets bonded with nanofilled flowable resins

Tain LV) were applied following the manufacturer’s instructions on the mesh pad of individual metallic brackets (Mini Dyna-Lock “Roth” .022 - 3M/Unitek, Monrovia, CA, USA) that were positioned on the enamel surface of the specimens and pressed firmly with a Hollenback carver to expel the excess adhesive. Each bracket was subjected to a 300-g compressive force using a force gauge (Correx Co, Berne, Switzerland) for 10 seconds, after which excess bonding resin was removed using a sharp scaler. Each specimen was was light-cured for 20 seconds from the occlusal edge and 20 seconds from the gingival bracket edge, with a light-curing unit (XL300, 3M/Unitek, Dental Products), with a light intensity of 1000 mW/cm2 measured with a built-in radiometer, which was calibrated every 10 minutes to ensure consistent light intensity.

The specimens were then immersed in deionized water and maintained in a oven at 37oC during 10 minutes or 24 hours, and the a shear bond strength (SBS) test was performed.

The shear bond strength test was conducted in a universal testing machine (Model 4411, Instron Corp, Canton, Mass., USA). A mounting jig was used to align the bracket-composite-enamel interface parallel to the testing devise. A chisel-edge plunger was applied the shear load at a crosshead speed of 0.5 mm/min until failure. Bond strength values were calculated in MPa. After debonding, each specimen was examined under a stereomicroscope (Olimpus SZX9, São Paulo, SP, Brazil) to identify the location of the bond failure. The residual composite remaining on the premolar was assessed by using the adhesive remnant index (ARI), where each specimen was scored according to the amount of

material remaining on the enamel surface as follows: 0 – no adhesive remaining, 1 – less than 50% of the adhesive remaining, 2 – more than 50% of the adhesive remaining, and 3 – all adhesive remaining with a distinct impression of the bracket base.

SBS data were submitted to Kruskal Wallis and Wilcoxon tests (p < 0.05). The ARI was analyzed for percentage and frequency of fracture type and submitted to Chi-Square test. Significance for all statistical tests was predetermined at p > 0.05. All of the statistical analyses were performed using BioEstat 5.0.

Results Shear Bond Strengths Mean bond strengths and standard deviations for each group are given in table I. Data were analyzed using Kruskal Wallis test (for comparisons among the materials in each period) and Wilcoxon test (for comparisons between 10 min and 24 hours for each material) (p < 0.05). There was a statistical significant difference among the materials at 10 min and 24 hours (p < 0.05). At 10 minutes, Transbond XT > Transbond Plus Color Change > Transbond Supreme LV = Flow Tain LV. At 24 hours, Transbond XT > Transbond Plus Color Change = Transbond Supreme LV = Flow Tain LV. The light-cured traditional materials (Transbond XT and Transbond Plus Color Change) showed the highest values compared with the nanofilled materials (Transbond Supreme LV and Flow Tain LV).

There was no statistical significant difference between 10 minutes and 24 hours except for Transbond Plus Color Change.

Table I – Mean (MPa) and standard deviation of shear bond strength (SBS) at 10 minutes and 24 hours for the different materials

Material

SBS at 10 minutes

SBS at 24 hours

Transbond XT

14.12 (4.53) Aa

10.20 (3.54) Aa

Transbond Plus Color Change

10.01 (3.12) Ba

5.82 (1.20) Bb

Transbond Supreme LV

5.46 (1.47) Ca

5.85 (1.06) Ba

Flow Tain LV

4.70 (1.40) Ca

6.02 (2.65) Ba

Different capital letters in columns (Kruskal Wallis test) and small letter in rows (Wilcoxon test) indicate statistical significant difference (p < 0.05)

Adhesive Remnant Index The distribution of failure modes, as expressed by ARI scores (%), is given in figure 1. According to statistical analysis (Chi-Square analysis) of the ARI scores, all of the test groups exhibited similar bracket failure modes (p > 0.05). Regardless of the bond material, bond failure occurred partly at the bracket-adhesive (resin) interface but mainly within the adhesive (resin) (score 1, 2 and 3). Enamel fractures were not observed in any of the specimens tested.

11 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):8-13 Morais et al. â&#x20AC;&#x201C; Shear bond strength of brackets bonded with nanofilled flowable resins

Figure 1 â&#x20AC;&#x201C; Distribution of failure modes, ARI scores (%), found after the SBS test

Discussion Orthodontics has sought reliable bonding materials that are able to withstand the chewing forces and the forces generated during movement in orthodontic treatment and, do not cause any damage to the enamel after removal of the orthodontic bracket.

The minimum shear bond strength of an adhesive should be between 5.9 and 7.9 MPa to be considered adequate for clinical needs, and at least 4.9 MPa for laboratory studies [20, 21]. When the results of this study were compared with these reference values, it was found that all materials evaluated comply with these values, considering both periods.

Besides the bond strength the bonding materials used in orthodontics should also have other features as good consistency, avoiding the displacement after positioning brackets or excesses that interfere with the thickness of the base resin, and appropriate working time.

Aiming to improve the materials characteristics, incorporating new technologies and improving their properties, the industry often develops new products for bracket bonding. One of the latest introduced features was the use of nanofilled resins. These resins that present smaller and uniformly distributed filler particles, might present greater cohesive strength to penetrate into the etched enamel and also in the bracket base resin, increasing the bond strength [2, 10, 17]. However, the results of this study showed a significant statistical difference between nanofilled low viscosity resins and traditional resins, with the nanofilled materials showing lower shear bond strength results than traditional resins. Thus, the hypothesis that there will be no differences among the materials could not be validated.

Designed for bracket bonding, Transbond XT is easily handle, which reduces working time; therefore, it has been widely used in clinical routine and also in laboratory studies as control group [5, 8, 12, 22, 28, 29]. Studies have shown similar SBS values of this material compared with nano-hybrid composite resin, photo- and chemical-cured resins and glass ionomer cements used for bracket bonding [5, 7, 8, 12, 22, 28, 29]. However, in this study, Transbond XT showed higher SBS values than the other materials. Despite the reduction in the resistance of 27.75% after 24 hours, there was no statistical difference between the two periods, which is in accordance with other studies [5, 8, 28].

Regarding the nanofilled resins, it was observed that both evaluated materials (Transbond Supreme LV and Flow Tain LV) had similar results, showing lower SBS values than traditional resins in both periods, except from Transbond Plus Color Change at 24 hours. Other study also found lower SBS values for nanofilled materials [5], however, the authors justified the results based on the higher viscosity of the nanofilled composite resin. However, the nanofilled materials used in this study present low viscosity and supposedly should present better infiltration in both etched enamel and in bracket base. Other studies found similar SBS values of nanofilled materials compared to traditional ones [13, 27].

The Transbond Plus Color Change showed intermediate SBS values at 10 min, lower than Transbond XT and higher than nanofilled materials [22]. This material was the only one that showed significant difference in SBS values at 10 min and 24 hours, with a decrease of 41.86% in the resistance.

This resin is a material characterized by its color change after curing, which facilitate the removal of excesses. According to the manufacturer, it releases

12 – RSBO. 2015 Jan-Mar;12(1):8-13 Morais et al. – Shear bond strength of brackets bonded with nanofilled flowable resins

fluoride and has hydrophilic characteristics, thus allowing its use on wet surfaces or contaminated by saliva. According to Tzou and Darrell [25], the hydrophilic nature of this resin allows diffusion of fluorine through photoactivation crosslinked matrix in aqueous medium. That characteristic could be related to the reduction in bond strength after storage in water.

Another important feature to be observed in bonding materials is the type of failure after bracket removal. A failure in the adhesive-enamel interface (score 0) could result in a greater risk for tooth enamel damage [4, 14]. In this study no specimen from all groups received an adhesive remnant index score of 0, indicating a minimal risk for enamel fractures. An adhesive remnant score of 3, failure at the bracket-adhesive interface was the most frequent score for all groups.

At 10 minutes, Tra nsbond XT showed a predominance of scores 1 and 2. For the other materials there was a predominance of scores 2 and 3 (failure at the interface resin/bracket). At 24 hours, all the materials showed a predominance of failure at the bracket-adhesive interface (scores 2 and 3) [8, 22]. This can be explained by the confinement of the resin between the mesh of the bracket, causing tensions that weaken this area.

Regarding the post-fixation time, there was no statistical significant difference between 10 minutes and 24 hours tests, except for Transbond Plus Color Change, as observed in other study [21]. Thus, the hypothesis that it would be no influence of postfixation time on SBS values could partially be validated. However, other studies have found greater SBS values for groups tested after 24 hours [7, 16]. This could be related to the materials selected in other studies, e.g., glass-ionomer cements and resin-modified glass-ionomer cements that reach its final resistance after 24 hours. In this study, only resin based materials (light or chemically-cured) were used, demonstrating that after 10 minutes the polymerization of the materials allowed the material to reach an adequate resistance to be tested.

For the Orthodontist, it is important to know the materials properties, since these materials must maintain orthodontic accessories firmly adhered to the teeth during the treatment. As shown in this study, many materials of different properties and characteristics can be used for bracket bonding.

However, Transbond XT seems to present some advantages, as it showed higher bond strength and predominance of score 1 type of failure, which would facilitate the removal of the resin remains from enamel surface after brackets removal.

Conclusion Based on the results of this study, it can be concluded that: • The light-cured traditional resins showed higher resistance than the nanofilled materials; • The period of fixation had no inf luence on the resistance for different materials, except for Transbond Plus Color Change; • There was a predominance of failure between the bonding material and the bracket base for all materials in both periods.

References 1. Albaladejo A, Montero J, Gómez de Diego R, López-Valverde A. Effect of adhesive application prior to bracket bonding with flowable composites.

Angle Orthod. 2011;81:716-20.

2. Andrade MV, Oliveira LGF, Filho PFM, Silva CHV. Tendências das resinas compostas nanoparticuladas. Int J Dent. 2009;8(2):153-7.

3. Birdsall J, Hunt NP, Sabbah W, Moseley HC. Accuracy of positioning three types of self-ligating brackets compared with a conventionally ligating bracket. J Ortho. 2012;30(1):34-42.

4. Bishara S, Truelove T. Comparisons of different debonding techniques for ceramic brackets: an in vitro study. Am J Orthod Dentofacial Orthop.

1990;98:145-53.

5. Bishara SE, Ajlouni R, Soliman MM, Oonsombat C, Faffon JF, Warren J. Evaluation of a new nanofilled restorative material for bonding orthodontic brackets. World J Orthod. 2007;8(1):8-12.

6. Cinader DK, James DS. Transbond™ supreme LV low viscosity light cure adhesive: suitable for indirect bonding. Orthodontic Perspectives.

Exploring Treatment Options. 2009;16:1.

7. Correr Sobrinho L, Correr GM, Consani S, Sinhoreti MA, Consani RL. Influence of postfixation time on shear bond strength of brackets fixed with different materials. Pesqui Odontol Bras.

2002;16:43-9.

8. Correr Sobrinho L, Consani S, Sinhoreti MAC, Correr GM, Consani RLX. Avaliação da resistência ao cisalhamento na colagem de bráquetes, utilizando diferentes materiais. Rev ABO Nac. 2001;9(2):157-62.

9. D’Attilio M, Traini T, Di Iorio D, Varvara G, Festa F, Tecco S. Shear bond strength, bond failure, and scanning electron microscopy analysis of a new flowable composite for orthodontic use. Angle Orthod. 2005;75:410-5.

13 – RSBO. 2015 Jan-Mar;12(1):8-13 Morais et al. – Shear bond strength of brackets bonded with nanofilled flowable resins

10. Eliades T. Orthodontic materials research and applications: part 1. Current status and projected future developments in bonding and adhesives. Am J Orthod Dentofacial Orthop. 2006;130:445-51.

11. Fonseca DDD, Costa DPTS, Cimões R, Beatrice LCS, Araújo ACS. Adesivos para colagem de bráquetes ortodônticos. RGO 2010;58:95-102.

12. Giannini C, Fransciscone PAS. Resistência à remoção de braquetes ortodônticos sob ação de diferentes cargas contínuas. Rev Dental Press Ortodon Ortop Facial. 2008;13(3):50-9.

13. Goracci C, Margvelashvili M, Giovannetti A, Vichi A, Ferrari M. Shear bond strength of orthodontic brackets bonded with a new selfadhering flowable resin composite. Clin Oral Investig. 2012;27. [Epub ahead of print].

14. Habibi M, Nik TH, Hooshmand T. Comparison of the debonding characteristics of metal and ceramic orthodontic brackets to enamel: an invitro study. Am J Orthod Dentofacial Orthop.

2007;132:675-9.

15. Jandt KD, Sigusch BW. Future perspective of resin-based materials. Dent Mater. 2009;25: 1001-6.

16. Minick GT, Oesterle LJ, Newman SM, Shellhart WC. Bracket bond strengths of new adhesive systems. Am J Orthod Dentofacial Orthop.

2009;135:771-6.

17. Mitra SB, Wu D, Holmes BN. An application of nanotechnology in advanced dental materials.

J Am Dent Assoc. 2003;134:1382-90.

18. Passalini P, Fidalgo TKS, Caldeira EM, Gleiser R, Nojima MCG, Maia LC. Mechanical properties of one and two-step fluoridated orthodontic resins submitted to different pH cycling regimes. Braz Oral Res. 2010;24(2):197-203.

19. Pick B, Rosa V, Azeredo TR, Cruz Filho EA, Miranda Jr WG. Are flowable resin-based composites a reliable material for metal orthodontic bracket bonding? J Contemp Dent Pract. 2010;11:17-24.

20. Reynolds IR, Von Fraunhofer JA. Direct bonding in orthodontics: a comparison of attachments. Br J Orthod. 1977;4:65-9.

21. Romano FL, Tavares SW, Ramalli EL, Magnani MBBA, Nouer DF. Análise in vitro da resistência ao cisalhamento de braquetes metálicos colados em incisivos bovinos e humanos. Rev Dental Press Ortodon Ortop Facial. 2004;9(6):63-9.

22. Romano FL, Correr AB, Correr Sobrinho L, Magnani MBBA, Siqueira VCV. Shear bond strength of metallic brackets bonded with a new orthodontic composite. Braz J Oral Sci. 2009;8(2):76-80.

23. Salerno M, Derchi G, Thorat S, Ceseracciu L, Ruffilli R, Barone AC. Surface morphology and mechanical properties of new-generation flowable resin composites for dental restoration. Dent Mater. 2011;27:1221-8.

24. Soo-Byung P, Woo-Sung SON, Ching-Chang KO, García-Godoy F, Mi-Gyoung P, Hyung-II KIM et al. Influence of flowable resins on the shear bond strength of orthodontic brackets. Dent Mater J. 2009;28:730-4.

25. Tzou S, Darrell J. Transbond plus color change adhesive: on-demand convenience with fluoride release, moisture tolerance and color change features. Orthodontic Perspective XIV. 2007;1:21-3.

26. Uysal T, Sari Z, Demir A. Are the flowable composites suitable for orthodontic bracket bonding? Angle Orthod. 2004;74:697-702.

27. Uysal T, Yagci A, Uysal B, Akdogan G. Are nano-composites and nano-ionomers suitable for orthodontic bracket bonding? Eur J Orthod.

2010;32:78-82.

28. Valletta R, Prisco D, Santis R, Ambrósio L, Martina R. Evaluation of the debonding strength of orthodontic brackets using three different bonding systems. Eur J Orthod. 2007;29:571-7.

29. Vicente A, Toledano M, Bravo LA, Romeo A, La Higuera B, Osório R. Effect of water contamination on the shear bond strength of five orthodontic adhesives. Med Oral Patol Oral Cir Bucal.

2010;15(5):820-6.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):14-22

Original Research Article

Effect of dentin desensitizers on resin cement bond strengths Rubens Nazareno Garcia1,2 Marcelo Giannini3 Tomohiro Takagaki4 Takaaki Sato4 Naoko Matsui4 Toru Nikaido4 Junji Tagami4 Corresponding author: Rubens Nazareno Garcia Rua Uruguai, n. 458 – Centro CEP 88302-202 – Itajaí – SC – Brasil E-mail: rubensgarcia@univali.br Department of Dentistry, University of Joinville Region – Joinville – SC – Brazil.

School of Dentistry, University of Itajai Valley – Itajai – SC – Brazil.

3 Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas – Piracicaba – SP – Brazil.

4 Department of Cariology and Operative Dentistry, Division of Oral Health Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University – Tokyo – Japan.

1 2

Received for publication: August 9, 2014. Accepted for publication: September 30, 2014.

Abstract Keywords: dentin desensitizing agents; dentin sensitivity; tensile bond strength.

Introduction: The crown preparation promotes the exposure of dentin tubules. Thus, to avoid post-operative sensitivity, the first approach involves the use of dentin adhesives, and the second one the use of dentin desensitizers. Objective: This study evaluated the effect of dentin desensitizers on microtensile bond strengths (µTBSs) of a resin cement to dentin. Material and methods: Twenty bovine teeth were prepared until obtaining flat dentin surfaces. A standardized smear layer was created (#600-grit SiC paper). The samples were randomly divided into the following four groups (n = 5): no treatment (Control), treatment with Gluma Desensitizer (Heraeus Kulzer), Super Seal (Phoenix Dental) and Teethmate Desensitizer (Kuraray Noritake Dental). The dentin surfaces were then treated with ED Primer II (Kuraray Noritake Dental). Twenty composite blocks, 4 mm thick (Estenia C&B, Kuraray Noritake Dental) were used. The composite surfaces were abraded with aluminum oxide (50 µm), and then silanized. The composite block was bonded to the dentin surface with a resin cement (Panavia F 2.0, Kuraray Noritake Dental) according to

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the manufacturer’s instructions. After 24-hour storage (37ºC, 100% RH), the bonded samples were cut into beam–shaped microtensile specimens and loaded in tension until failure. Data were analyzed with one-way ANOVA and the Dunnett’s test (α = 0.05). An SEM was used to examine the failure modes. Results: The µTBSs (MPa ± SD) were: 24.4 ± 3.2 (Control), 14.0 ± 5.6 (Gluma Desensitizer), 8.6 ± 4.7 (Super Seal), and 34.7 ± 4.6 (Teethmate Desensitizer), in which there were significant differences among the four groups (p < 0.05).

The Teethmate Desensitizer group showed the highest µTBS, while the Super Seal group showed the lowest mean of µTBS to dentin.

Conclusion: The efficacy of the desensitizers is material-dependent; Gluma Desensitizer and Super Seal decreased the µTBSs, however, Teethmate Desensitizer improved it.

Introduction The exposure of the dentin tubules is inevitable during cavity or crown preparations [20]. Once the tubules are opened, they act as channels that transmit mechanical, chemical and bacterial stimuli to t he pulp [18]. Prov isiona l sea ling materials do not cohesively bind to dentin and may permit leakage to bacteria and their products before the luting of final restoration. During the provisional stage, the dentin may also encounter external stimuli that include impression taking, rinsing, drying, and removal of temporary sealing, which may all encourage tooth sensitivity and potential pulp damage [3]. Thus, coating should be performed immediately a fter cutt ing t he dentin and provide a biological seal that acts as a dentin-pulp protector. To serve this aim, it has been suggested that freshly cut dentin surfaces for indirect restorations could be sealed with resinbased adhesives prior to the taking impressions, so-called resin coating technique [16]. In addition to its favorable effects on reduction of postpreparation and post-cementation sensitivities, this also called immediate dentin sealing technique [15] can result in significantly increased retention, reduced marginal leakage, and improved bond strengths [7, 8], when used for traditional crown preparations of vital teeth [13].

The most widely accepted mechanism of dentin sensitivity is the so-called hydrodynamic theory of sensitivity. It postulates that rapid shifts, in either

direction, of the fluids within the dentinal tubules, following stimulus application, result in activation of sensory nerves in the pulp/inner dentin region of the tooth [1, 9].

Conventional therapy for dentin sensitivity is based on using topical application of desensitizing agents which can be applied either professionally or can be described to the patient for home use.

The ideal desensitizer agent should not irritate or endanger the integrity of the pulp, should be relatively painless on application or shortly afterward, should be easily applied, rapid in action, permanently effective and finally should not discolour tooth structure [4].

The aim of the present study was to investigate the effect of dentin desensitizers on resin cement bond strengths to dentin, by evaluating microtensile bond strength and failure analysis. Null hypothesis of this study was that dentin bond strengths of a resin cement were not affected by the different dentin desensitizing agents.

Material and methods Materials used in this study Three desensitizers (Gluma, Heraeus Kulzer, Dormagen, Germany; Super Seal, Phoenix Dental, Fenton, MI, USA; and Teethmate Desensitizer, Kuraray Noritake Dental, Tokyo, Japan), a resin cement (Panavia F 2.0, Kuraray Noritake Dental) and an indirect composite resin (Estenia C&B, Kuraray Noritake Dental) were used in this study (Table I).

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Table I – Materials used in this study

Material

Batch

Composition Bis-GMA, TEGDMA, photoinitiator, silanized ceramic microfillers, silica

Estenia C&B Kuraray Noritake Dental

0098AA/ 0101AA

K-etchant GEL Kuraray Noritake Dental

00522A

37% phosphoric acid

01170A

MDP, HEMA, hydrophilic dimethacrylate, dl-camphorquinone, N,Ndiethanol-p-toluidine, water

00262B

3-trimethoxysilylpropyl methacrylate, hydrophobic aromatic dimethacrylate, others

Clearfil SE Bond Primer Kuraray Noritake Dental Clearfil Porcelain Bond Activator Kuraray Noritake Dental

Panavia F2.0 Kuraray Noritake Dental

Paste A: 00550A Paste B: 00276A

ED Primer II Kuraray Noritake Dental (pH 2.4)

Liquid A: 00313A Liquid B: 00187B

Teethmate Desensitizer Kuraray Noritake Dental

000001

Paste A: Methacrylate, MDP, quartz-glass, microfillers, photoinitiator

Paste B: Methacrylate, barium glass, sodium fluoride, chemical initiator HEMA, MDP, MASA, water, accelerators MASA, water, catalysts, accelerators Powder: Tetrocalcium phosphate, dibasic calcium phosphate Liquid: water

Gluma Desensitizer Heraeus Kulzer

010209

35% HEMA, 5% glutaraldehyde, water

Super Seal Phoenix Dental

991631

Oxalic acid, potassium salt, water

Estenia blocks (preparation): Apply the material into matrix (3 mm thick), light cure (40 sec each side), lab light cure oven (3 min), lab hot oven (15 min), sandblasting to aluminum oxide (50 µm / 0.1MPa / 10mm distance / 10sec) Estenia side (silanation): Air drying (5 sec), K-etchant GEL (5 sec), wash (5 sec), Air drying (5 sec), mix 1 drop of Clearfil Mega Bond primer and 1 drop of Clearfil Porcelain Bond Activator, apply and wait (30 sec), air drying (5 sec)

Dentin side: Air drying (5 sec), mix ED primer II A and B (1 drop each one), apply ED primer to dentin surface by small brush or sponge (just waiting 30 sec), air drying (5 sec), put paste A and paste B same amount on paper and mix (20 sec), apply the paste on Estenia, light cure (40 sec each side)

Mix powder and liquid (more than 15 sec), apply (rubbing more than 30 sec), wash (5 sec), clean the dentin surface by wet swab/cotton (more than 10 sec/use distilled water) Air drying (5 sec), apply (rubbing 30 sec), air drying (5 sec), wash (5 sec), air drying (5 sec) Air drying (5 sec), apply at least 5 sec (rubbing 10 sec), air drying (3 sec – mild 10 cm distance)

Abbreviations: Bis-GMA: bisphenol A glycidyl methacrylate; TEGDMA: triethyleneglycol dimethacrylate; MDP: 10methacrylate oxydecyl dihydrogen phosphate; NaF: sodium fluoride; BPO: benzoyl peroxide; MASA: N-methacrylolyl5-aminosalicylic acid; HEMA: 2-hydroxyethylmethacrylate

Specimen preparation for microtensile bond test Twenty bovine lower central incisors were used as bonding substrates. The teeth were stored in water at 4°C and used within one month after

extraction. Each tooth was sectioned in the root and in the labial surface, approximately 1 mm below the enamel-dentin junction using a low-speed diamond saw (Isomet, Buehler, Lake Bluff, IL, USA) under water stream. The teeth were prepared until obtaining middle portion of flat dentin surfaces.

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Twenty indirect composite restorative blocks were fabricated using Estenia C&B (Table I). A cylindrical Teflon mold (4 mm deep and 10 mm in diameter) was made. The Estenia C&B was placed into this mold by two increments. Each increment was light cured for 40 s (Optilux 501; Kerr Corp, Orange, CA, USA / 600mW/cm2). Afterwards, the blocks were light cured 3 min and heat cured for 15 min with an Estenia polymerization device (CS110 light and heat curing unit; Kuraray Noritake Dental). Then, the surfaces of the composite blocks were abraded with 50-µm aluminum oxide (0.1 MPa, 10 mm distance, 10 s). Also, the Estenia C&B blocks were silanized.

The dentin surface was ground with 600grit SiC paper under a water spray to create a standard smear layer, just before each adhesive procedure to simulate to the clinical treatment method, in which the smear layer was created by rotary instruments [17]. The teeth were randomly distributed into four groups (n = 5) according to the experimental groups: [1] control group, only ED Primer II (Kuraray Noritake Dental); [2] Gluma + ED; [3] Super Seal + ED; [4] TMD + ED. Afterwards, blocks of Estenia C&B were cemented to t he sa mples under a load (500 g weight) using Panav ia F 2.0 resin cement, which was light-activated for 40 s (Optilux 501; 600 mW/cm2). After 24-hour storage (37ºC, 100% RH), the bonded samples were then perpendicularly sectioned with a diamond saw (Isomet 1000) under water lubrication. The samples were cut into beam–shaped microtensile specimens with an adhesive area of approximately 1 mm2. These specimens were fixed to an universal testing machine (EZ-Test / Shimadzu, Kyoto, Japan) with a cyanoacrylate adhesive (Zapit, DVA, Anaheim Hills, CA, USA) and subjected to microtensile bond strength (µTBS) testing at a crosshead speed of 1 mm/min.

Scanning Electron Microscopy (SEM) observations The representative specimens for each failure mode were examined by using SEM (JSM-5310LV; Jeol, Tokyo, Japan). Prior to the SEM observations, the specimens were air-dried and sputter-coated with gold. Failure modes were categorized as: adhesive failure at the resin cement-dentin interface (AD), cohesive failure within dentin (CD), cohesive failure

within resin cement (CRC), mixed failure (AD + CRC), and mixed failure (CRC + TMD layer).

The dentin surfaces treated with four different treatment groups were also examined (SEM / JSM5310LV; Jeol, Tokyo, Japan). After the specimens were treated in the same manner of the adhesive procedures described above, the treated specimens were air-dried and sputter-coated with gold for SEM examination.

Statistics The µTBS data were statistically analyzed using a One-way ANOVA and the Dunnett’s test. The statistical significance level was always set at α = 0.05. The survival rate was analysed by Chi-square test with Bonferroni correction (p < 0.05).

Results Microtensile bond strength testing and failure modes Means μTBS are presented in Table II. One-way ANOVA showed significant differences among the groups (p < 0.001). The TMD group showed the highest μTBS, while the Super Seal desensitizer showed the lowest one. As presented in Table III, the control group showed mainly CRC failure. The Gluma group showed 50% mixed (AD + CRC) failure, 30% AD failure and 20% CRC failure.

The Super Seal group showed 90% AD failure and the TMD showed 50% CRC failure and 50% mixed (CRC + TMD) failure.

The SEM micrographs of the dentin surfaces treated with four different treatment groups were shown in Figures 1 to 4. For the control group (Group 1), the dentin surface was covered by the smear layer. The dentinal tubules were closed (Figure 1). For Gluma Desensitizer (Group 2), the dentinal tubules were partially closed. A coating layer with the desensitizing material was not visually confirmed under the low magnification of the observation (Figure 2). For Super Seal (Group 3), small precipitates were deposited on the intertubular dentin. The dentinal tubules were occluded by the depositions (Figure 3). For Teethmate Desensitizer (Group 4), the scratches on the dentin surface with #600-grit SiC paper disappeared. Depositions covered the intertubular dentin and occluded the dentinal tubules (Figure 4).

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Table II – µTBSs means to bovine dentin

Group

Mean ± SD*

Survival rate (%)**

[1] Control

24.3 ± 3.2 B

100 a

[2] Gluma

14.0 ± 5.6 C

100 a

[3] Super Seal

08.6 ± 4.7 D

40 b

[4] Teethmate Desensitizer

34.7 ± 4.6 A

100 a

Means (SD) in MPa, (n = 5). Same letters in the column are not statistically significant (p < 0.05) * One-way ANOVA and Dunnett’s test. ** Chi-square test with Bonferroni correction

Table III – Failure modes (%)

Group

AD

CD

CRC

AD+CRC

CRC+TMD layer

[1] Control

0

0

90

10

0

[2] Gluma

30

0

20

50

0

[3] Super Seal

90

0

0

10

0

[4] Teethmate Desensitizer

0

0

50

0

50

AD = Adhesive / CD = Cohesive in dentin / CRC = Cohesive in resin cement / AD+CRC = Adhesive and cohesive in resin cement / CRC+TMD layer = Cohesive in resin cement and TMD layer

Figure 1 – SEM micrographs of the dentin surface ground with #600-grit SiC paper (Group 1 - Control) (x2,000). The dentin surface was covered by the smear layer. The dentinal tubules were closed

Figure 2 – SEM micrographs of the dentin surface treated with Gluma Desensitizer (Group 2) (x2,000). The dentinal tubules were partially closed. A coating layer with the desensitizing material was not visually confirmed under the low magnification of the observation

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Figure 3 – SEM micrographs of the dentin surface treated with Super Seal (Group 3) (x2,000). Small precipitates were deposited on the intertubular dentin. The dentinal tubules were occluded by the depositions

Figure 4 – SEM micrographs of the dentin surface treated with Teethmate Desensitizer (Group 4) (x2,000).

The scratches on the dentin surface with #600-grit SiC paper disappeared. Depositions covered the intertubular dentin and occluded the dentinal tubules

Discussion There is an understanding that the treatment of the dentin sensitivity mainly has being focused on the tubular occlusion [12, 19]. For the sealing of the dentinal tubules, there is the method of using a smear layer that can decrease the level of dentin permeability by 98%, when compared to dentin treated with acid [5]. Regarding the SEM analysis of the control group, the micrographs showed closed

dentinal tubules by the smear layer and 90% of cohesive failures in the resin cement (Figure 1).

The ED Primer II and Panavia F 2.0 contain MDP (10-methacrylate oxydecyl dihydrogen phosphate).

The preservation of hydroxyapatite (HAp) within the submicron hybrid layer may serve as receptor for additional chemical bonding. MDP has this chemical bonding potential to calcium of residual HAp [30]. One may hypothesize that a self-etching effect of MDP is mandatory in order to deal with the smear layer resulting from tooth preparation and achieving shallow micromechanical interlocking through hybridization at dentin. In addition, the exposed HAp crystals that remain around collagen are expected to be particularly advantageous. They enable more intimate chemical interaction with the functional monomers on a molecular level and may help prevent or retard marginal leakage [27]. Keeping HAp around collagen may also better protect the collagen against hydrolysis and thus, prevent from early degradation of the bond [10, 21]. It is reported that ionic bond of MDP with calcium appeared to be hydrolytically stable, as compared with 4-META (4-methacryloxyethyl trimellitic acid) and Phenyl-P (2-metha-cryloyloxyethyl phenyl phosphoric acid).

It was capable of forming strong ionic bonds with calcium due to the superficial dissolution of HAp induced by the MDP adsorption and subsequent deposition of MDP-calcium salt with a lower solubility [30].

In this study, a well-established µTBS protocol was used to investigate the adhesive luting of one indirect composite resin to dentin, using three different treatments of dentin desensitizer agents.

In the present study, the control group [1] showed higher bond strength when compared to group [2] and [3].

Gluma Desensit izer is a gluta ra ldehydeb a s e s u b s t a n c e t h a t c o n t a i n s H E M A (2 hydroxyethylmethacrylate), causing the coagulation of the dentin fluid proteins in the dentinal tubules and plugs the tubules [6, 24]. In fact, glutaraldehyde causes coagulation of proteins inside the dentinal tubules, reacting with the albumin in the dentinal fluid, thus causing the precipitation of albumin and blockage of tubules. Therefore, Gluma reduces dentin permeability and disinfects the dentin at the same time. Especially when glutaraldehyde was combined with HEMA, bond strengths were improved [22].

Despite dent i n precipit at ion a fter toot h preparation, the diffusion of monomers to dentin is likely to be accelerated by the presence of HEMA, because this product has the ability to

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promote dentin adhesion and helps in facilitating diffusion of resin monomer and the formation of hybrid layer.

However, some in vitro studies have showed an inhibiting effect of Gluma on the bond strength of conventional resin cements, as a consequence of this coagulation of dentin fluid proteins and plugging the tubules [11, 28].

In the present study, a self-etching primer (ED Primer II) was used. Gluma did not contribute to improve the bond strength, because Gluma has a better mechanism of action when used to etch-and-rinse approach, when occurs the rewet or the restablishment of the collagen fibrils [24].

Regarding the SEM analysis, the micrographs showed semi-closed dentinal tubules, but it did not form a thick coating, and 50% mixed failures (between adhesive and cohesive in resin cement), 30% adhesive and 20% cohesive failures in resin cement failures (Figure 2).

Super Seal desensitizer agent is an oxalatebased substance. When acidic oxalates are applied to the dentin surface, they liberate calcium from the dentin to produce an insoluble calcium oxalate crystals that block dentinal tubules [11]. Hydrophilic calcium oxalate forms an insoluble crystalline layer on intratubular dentin matrix. It is acidic enough to remove the smear layer, and replace it with a layer of calcium oxalate crystals. To the present study, Super Seal showed the lowest bond strength mean among the groups. This might be because of the pH = 2.4 of ED Primer II, once there is an incompatibility of oxalate desensitizers agents with the acidic materials [29]. The solubility of calcium oxalate is affected by pH, since the anion is the conjugate base of a weak acid [14].

The SEM analysis showed precipitates that were deposited on dentin surface with limited penetration into the tubules (Figure 3), resulting in 90% of adhesive failures and a survival rate of only 40% of the specimens.

Teethmate Desensitizer is a calcium-phosphate desensitizer agent that contains TTCP (tetracalcium phosphate) a nd DCPA (dica lcium phosphate anhydrous) with water, whose combination could spontaneously transform to HAp. Previous reports [2, 25, 26] showed that the precipitates or crystallites were found in tubular orifices and on dentin surface, suggesting that the presence of HAp in the dentin substance could enhance the setting reaction of TMD and serve as a substrate for heterogeneous nucleation (deposition of crystals on foreign bodies, considered as potentiators of crystallization).

The chemical bond might be formed between

the material layer and the smear layer deprived dentin surface in a clinically reasonable time.

According to the same authors, the effectiveness of TMD in forming a layer on dentin regardless of pretreatment and maintaining tubule occlusion should be attributed to its chemical composition.

The mixing of the two components (TTCP and DCPA) provided a thick paste which could penetrate into the dentinal tubules by mean of scrubbing on dry dentin surface. This occluding effect resulted in the immediate dentinal permeability reduction and, hence, clinical sensitivity reduction could be expected [23]. To this study, TMD (group 4) showed the highest microtensile bond strength mean among all groups. This is because of this supposed chemical interaction created between the TMD and the smear layer and dentin, was possible to confirm in the SEM images.

The images showed a deposited layer of TMD covering the dentin surface and the occlusion of the dentinal tubules (figure 4). The TMD showed 50% cohesive failures in resin cement and 50% mixed failures (cohesive in resin cement and in TMD layer).

Based on the findings of the present study, the formulated null hypothesis was rejected, because the results differ significantly in µTBS among all groups tested. The current results indicate a relevant clinical significance because the TMD desensitizer is expected to be a new generation of material forming a stable calcium-phosphate rich layer and enhancing the calcification under oral conditions. It has biocompatible property, outstanding characteristic in dentinal tubule occlusion and favorable reduction in dentin permeability in the oral environment.

Conclusion The efficacy of the desensitizers is materialdependent; Glu ma D esensit i zer a nd Super Seal decreased the µTBSs, however, Teethmate Desensitizer improved it.

Acknowledgements This work was supported by the University of Joinville Region (Univille/post-doctoral scholarship), Department of Dentistry, Joinville, Brazil and the Global Center of Excellence (GCOE) Program, IRCMSTBD and Cariology and Operative Dentistry, Department of Oral Health Sciences at Tokyo Medical and Dental University, Tokyo, Japan.

21 – RSBO. 2015 Jan-Mar;12(1):14-22 Garcia et al. – Effect of dentin desensitizers on resin cement bond strengths

References 1. Brännström M. The elicitation of pain in the human dentine and pulp by chemical stimuli. Arch Oral Biol. 1962;7:59-62.

2. Chow LC. Next generation calcium phosphatebased biomaterials. Dent Mater J. 2009;28:1-10.

3. Christensen GJ. Tooth preparation and pulp degeneration. J Am Dent Assoc. 1997;128(3):353-4.

4. Dababneh RH, Khouri AT, Addy M. Dentine hypersensitivity – an enigma? A review of terminology, mechanisms, aetiology and management. Br Dent J. 1999;187(11):606-11.

5. Elgalaid TO, Youngson CC, McHugh S, Hall AF, Creanor SL, Foye RH. In vitro dentine permeability: the relative effect of a dentine bonding agent on crown preparations. J Dent. 2004;32(5):413-21.

6. Felton DA, Bergenholtz G, Kanoy BE. Evaluation of the desensitizing effect of gluma dentin bond on teeth prepared for complete-coverage restorations.

Int J Prosthodont. 1991;4(3):292-8.

7. Garcia RN, Reis AF, Giannini M. Effect of activation mode of dual-cured resin cements and low-viscosity composite liners on bond strength to dentin. J Dent. 2007;35(7):564-9.

8. Giannini M, De Goes MF, Nikaido T, Shimada Y, Tagami J. Influence of activation mode of dualcured resin composite cores and low-viscosity composite liners on bond strength to dentin treated with self-etching adhesives. J Adhes Dent.

2004;6(4):301-6.

9. Gysi A. An attempt to explain the sensitiveness of dentin. Br J Dent Sci. 1900;43:865-8.

10. Hashimoto M, Ohno H, Sano H, Tay FR, Kaga M, Kudoi Y et al. Micromorphological changes in resin-dentin bonds after 1 year of water storage.

J Biomed Mat Res. 2002;63(3):306-11.

11. Huh JB, Kim JH, Chung MK, Lee HY, Choi YG, Shim JS. The effect of several dentin desensitizers on shear bond strength of adhesive resin luting cement using self-etching primer. J Dent. 2008;36(12):1025-32.

12. Imai Y, Akimoto T. New method of treatment for dentin hypersensitivity by precipitation of calcium phosphate in situ. Dent Mater J. 1990;9:167-72.

13. Kosaka S, Kajihara H, Kurashige H, Tanaka T. Effect of resin coating as a means of preventing marginal leakage beneath full cast crowns. Dent Mater J. 2005;24(1):117-22.

14. Kotz JC, Treichel P. Principles of reactivity: precipitation reactions. Chemistry and chemical reactivity. 4. ed. Fort Worth (TX): Saunders College Pub; 1999. p. 897-8.

15. Magne P. Immediate dentin sealing: a fundamental procedure for indirect bonded restorations. J Esthet Restor Dent. 2005;17(3):14454.

16. Nikaido T, Nakaoki Y, Ogata M, Foxton R, Tagami J. The resin-coating technique. Effect of a single-step bonding system on dentin bond strengths. J Adhes Dent. 2003;5(4):293-300.

17. Ogata M, Harada N, Yamaguchi S, Nakajima M, Tagami J. Effect of self-etching primer vs phosphoric acid etchant on bonding to burprepared dentin. Oper Dent. 2002;27:447-54.

18. Pashley EL, Comer RW, Simpson MD, Horner JA, Pashley DH, Caughman WF. Dentin permeability: sealing the dentin in crown preparations. Oper Dent. 1992;17(1):13-20.

19. Porto IC, Andrade AK, Montes MA. Diagnosis and treatment of dentinal hypersensitivity. J Oral Sci. 2009;51:323-32.

20. Sahin C, Cehreli ZC, Yenigul M, Dayangac B. In vitro permeability of etch-and-rinse and self-etch adhesives used for immediate dentin sealing. Dent Mater J. 2012;31(3):401-8.

21. Sano H, Yoshikawa T, Pereira PN, Kanemura N, Morigami M, Tagami J et al. Long-term durability of dentin bonds made with a self-etching primer, in vivo. J Dent Res. 1999;78(4):906-11.

22. Schmidlin PR, Zehnder M, Göhring TN, Waltimo TM. Glutaraldehyde in bonding systems disinfects dentin in vitro. J Adhes Dent. 2004;6(1):61-4.

23. Shetty S, Kohad R, Yeltiwar R. Hydroxyapatite as an inoffice agent for tooth hypersensitivity: a clinical and scanning electron microscopic study.

J Periodontol. 2010;81:1781-9.

24. Stawarczyk B, Hartmann R, Hartmann L, Roos M, Ozcan M, Sailer I et al. The effect of dentin desensitizer on shear bond strength of conventional and self-adhesive resin luting cements after aging.

Oper Dent. 2011;36(5):492-501.

25. Thanatvarakorn O, Nakashima S, Sadr A, Prasansuttiporn T, Ikeda M, Tagami J. In vitro evaluation of dentinal hydraulic conductance and tubule sealing by a novel calcium-phosphate desensitizer. J Biomed Mater Res Part B. 2013;101B:303-9.

22 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):14-22 Garcia et al. â&#x20AC;&#x201C; Effect of dentin desensitizers on resin cement bond strengths

26. Thanatvarakorn O, Nakashima S, Sadr A, Prasansuttiporn T, Thitthaweerat S, Tagami J. Effect of a calcium-phosphate based desensitizer on dentin surface characteristics. Dent Mater J. 2013;32(4):615-21.

27. Van Meerbeek B, De Munck J, Yoshida Y, Inoue S, Vargas M, Vijay P et al. Adhesion to enamel and dentin: current status and future challenges. Oper Dent. 2003;28(3):215-35.

28. Yim NH, Rueggeberg FA, Caughman WF, Gardner FM, Pashley DH. Effect of dentin desensitizers and

cementing agents on retention of full crowns using standardized crown preparations. J Prosthet Dent.

2000;83(4):459-65.

29. Yiu CKY, King NM, Suh BI, Sharp LJ, Carvalho RM, Pashley DH et al. Incompatibility of oxalate desensitizers with acidic fluoride-containing totaletch adhesives. J Dent Res. 2005;84(8):730-5.

30. Yoshida Y, Nagakane K, Fukuda R, Nakayama Y, Okazaki M, Shintani H et al. Comparative study on adhesive performance of functional monomers.

J Dent Res. 2004;83(6):454-8.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):23-31

Original Research Article

Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion Tiago André Fontoura de Melo1 Cíntia Muniz Couto1 Corresponding author: Tiago André Fontoura de Melo Rua Eça de Queiroz, n. 466, apartamento 701 – Petrópolis CEP 90670-020 – Porto Alegre – RS – Brasil E-mail: tafmelo@gmail.com 1

Department of Dentistry, São Leopoldo Mandic/SP Post-Graduation Center, Porto Alegre unit – Porto Alegre – RS – Brazil.

Received for publication: March 12, 2014. Accepted for publication: September 23, 2014.

Keywords: tooth avulsion; tooth replantation; health knowledge, attitudes, practice.

Abstract Introduction and Objective: The present study aimed to evaluate the knowledge level of students graduate in Dentistry of São Leopoldo Mandic/SP – Porto Alegre/RS on the therapeutic approach in cases of dental avulsion. Material and methods: For this, we applied a questionnaire to graduate students. Of the 214 students enrolled at the institution, 159 (74%) answered the questions. Results and Conclusion: Through analysis of the responses, it could be observed that, while 99.37% of participants have already received instructions about the subject, there was significant variability of opinions.

With the application of Chi-square test, at a significance level of 5%, it could be observed that there was no significant difference in responses regarding to the time of graduation. As for the type of splinting, the professionals who graduated between 5 to 10 years were associated with the use of semi-rigid splint and those who graduate after more than 10 years with the rigid splint.

Introduction Tooth avulsion is one of the dental situations of more complex, diagnosis, treatment and followup because the approach should always be well

planned in the context of limiting the risk of infection in the root canal, minimizing the extent of the inflammation surrounding the region of the supporting tissue, and maintaining the aesthetic pattern of the patient.

24 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

Successful replantation is closely related to several factors, such as extra-alveolar time and the form of management of the avulsed tooth [20].

Thus, the treatment of avulsion, when performed in adverse conditions may result, over time, in tooth ankylosis, and inflammatory or replacement root resorption [5, 10].

Therefore, prior knowledge about an effective approach in accordance with proper care related to tooth replantation is a key factor.

Some studies have been conducted to assess the knowledge of parents or guardians [14, 22, 25], professors [2, 18], Dentistry undergraduates [13] and health professionals [9, 12] on the therapeutic approach of avulsed teeth.

França et al. [12] applied a questionnaire to 93 dentists in the city of Tubarão, and found that 36.6% of participants chose the answer considered correct for a situation of tooth avulsion of a 12 year old patient who took his tooth at the time of the appointment.

On the other hand, Díaz et al. [9] conducted a survey on doctors and paramedics in Chile, through the application of a questionnaire, and found that, of the 82 participants, 43.9% claimed that they do not replanted an avulsed tooth because the dentist is responsible for this procedure and only 9.8% answered correctly on storage methods.

In 2010, Zhao and Gong [31] evaluated the knowledge on the treatment of avulsion of 274 dentists from 15 hospitals in Beijing (China), and concluded that there is no consensus on the storage medium, dental splinting technique and type of intracanal medication used.

Because of the variety of responses observed in different studies and because the dentist is the professional technically qualified for the treatment of this type of injury, this study aimed to evaluate the level of knowledge of dental graduates from São Leopoldo Mandic (SP) Post-Graduation Center – Porto Alegre (RS) unit on the therapeutic approach in cases of tooth avulsion.

Initially, the students were informed on the study objectives to let them know the importance a nd t he releva nce of t heir responses to t he questionnaire to assess the knowledge of dentists on how to approach in cases of tooth avulsion.

The questionnaire (Figures 1 and 2) was applied to all students voluntarily. It was assured the participants that their identity would be kept secret. All respondents signed a free and cla rified consent form before a nswering t he questionnaire.

Graduation time: ( ) up to 5 years ( ) 5 to 1o years ( ) more than 10 years Which specialization course are you enrolled? __________________________________________________ During your graduation, have you ever received any instruction on how to proceed in tooth avulsion cases? ( ) yes ( ) no Have you ever treated any tooth avulsion case? ( ) yes ( ) no Figure 1 – Questionnaire regarding the professionals’ data and knowledge level on dental avulsion

If a child accidentally fall on the street and the maxillary right permanent central incisor (tooth #11) is avulsed without bone fracture and the patient is referred to you, answer the following questions: 1) Concerning to avulsed tooth socket, you: ( ) would not clean it ( ) would only clean it with saline solution ( ) would perform the curettage and clean it with saline solution 2) In case of tooth replantation, you: ( ) would maintain the tooth without splinting ( ) would use semi-rigid splinting

Material and methods

( ) would use rigid splinting

A quantitative research was conducted through an objective questionnaire on the students enrolled in the Dentistry Post-Graduation Program, lato sensu, of São Leopoldo Mandic (SP) Post-Graduation Center – Porto Alegre (RS) unit, in October 2012.

The st udents pa rt icipat i ng i n t he st udy were enrolled in the specialization courses in Endodontics, Prosthodontics, Implant Dentistry, Orthodontics and Radiology.

3) For how long would you maintain the splinting? ( ) I would not use splinting ( ) 7 days ( ) 15 days ( ) more than 30 days (Continues on the next page)

25 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

4) Considering the avulsion of the maxillary right permanent central incisor, the splinting should include, at least: ( ) one tooth at each side of the avulsed tooth ( ) two teeth at each side of the avulsed tooth ( ) up to the maxillary second premolars ( ) all maxillary teeth 5) How would you manage the avulsed tooth elapsed two hours after the trauma: ( ) would not replant ( ) would replant without prior endodontic treatment ( ) would perform endodontic treatment before replanting ( ) would remove all periodontal tissues adhered to root surface, treat the root surface, treat the root canal before replanting For you, which would be the most important factor for tooth replantation success? ( ) extra-alveolar time of avulsed tooth ( ) periodontal ligament condition ( ) rhizogenesis stage ( ) storage of the avulsed tooth Facing the avulsion of a maxillary primary central incisor, with 2/3 of sound root, what would you do? ( ) tooth replantation and follow-up ( ) would not replant Figure 2 – Questionnaire to evaluate the knowledge on the treatment of avulsed teeth

The students were asked to mark only one answer per question, not being allowed to consult the scientific literature on the subject.

After collection, the data were tabulated and verified statistically by using the Chi-square test at a significance level of 5%.

Results Of 214 dental graduates enrolled in São Leopoldo Mandic (SP) Post-Graduation Center – Porto Alegre (RS) unit, 159 graduates participated in this present study (74%).

Table I shows the graduates’ distribution according to the graduation time, specialty and level of previous knowledge on tooth avulsion.

Table I – Distribution of the graduates regarding to professional data and level of previous knowledge on tooth avulsion

Frequency (n)

Percentage (%)

Up to 5 years

112

70.44%

5 to 10 years

31

19.49%

More than 10 years

16

10.06%

Endodontics

23

14.46%

Implant Dentistry

9

5.66%

Orthodontics

73

45.91%

Dental Prosthesis

46

28.93%

Radiology

8

5.03%

Yes

158

99.37%

No

1

0.62%

Yes

30

18,86%

No

129

81,13%

Variables Graduation time

Post-graduation Course

Previous knowledge on avulsion

Treatment of tooth avulsion

Concerning to tooth avulsion approach and treatment, the results are seen in figures 3 to 9.

26 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

Would not clean

Counting % inside the time

14 12.5%

4 12.9%

6 37.5%

clean with saline

Counting % inside the time

79 70.5%

23 74.2%

7 43.8%

curettage+ clean with saline

Counting % inside the time

19 17%

4 12.9%

3 18.8%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Asymp sig (2-sided)

Pearson’s chi-square

a

7.871

4

.096

Likelihood ratio

6.560

4

.161

linear by linear association

2.083

1

.149

N of valid cases

159

a. 3 cells (33.33%) expected counting lower than 5. The minimum expected counting is 2.42.

Figure 3 – Results regarding to the procedure performed in the socket of the avulsed tooth in function of the graduation time

Through Chi-square test, with p = 0.096, it was verified no association between the graduation time and the response on the procedure carried out in the socket of the avulsed tooth.

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

no splinting

Counting % inside the time

0 0%

0 0%

1 6.3%

semi-rigid splinting

Counting % inside the time

82 73.2%

27 87.1%

6 37.5%

rigid splinting

Counting % inside the time

30 26.8%

4 12.9%

9 56.3%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Asymp sig (2-sided)

Pearson’s chi-square

19.909a

4

.001

Likelihood ratio

15.431

4

.004

linear by linear association

.773

1

.379

N of valid cases

159

a. 4 cells (44.4%) expected counting lower than 5. The minimum expected counting is .10.

Figure 4 – Results regarding to the splinting type in function of the graduation time

Through Chi-square test, complemented by the Analysis Of Adjusted Residuals, at level of significance of 5%, it was verified that the professional who graduated from 5 to 10 years were locally associated with the use of semi-rigid splinting and those who graduated from more than 10 years with rigid splinting.

27 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

no splinting/up to 7 years

Counting % inside the time

8 7.1%

2 6.5%

2 12.5%

15 days

Counting % inside the time

58 51.8%

16 51.6%

3 18.8%

more than 30 days

Counting % inside the time

46 41.1%

13 41.9%

11 68.8%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Pearson’s chi-square

6.304

4

.178

Likelihood ratio

6.784

4

.148

linear by linear association

1.343

1

.246

N of valid cases

159

a

Asymp sig (2-sided)

a. 2 cells (22.2%) expected counting lower than 5. The minimum expected counting is 1.21

Figure 5 – Results regarding to the splinting time in function of the graduation time

Through Chi-square test, with p = 0.178, no association was verified between the graduation time and the response on the splinting time.

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

one tooth at each side

Counting % inside the time

25 22.3%

9 29%

6 37.5%

two teeth at each side

Counting % inside the time

84 75%

22 71%

9 56.3%

up to 2nd premolar area/ all maxilla

Counting % inside the time

2 2.7%

0 0%

1 6.3%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Asymp sig (2-sided)

Pearson’s chi-square

3.881a

4

.422

Likelihood ratio

4.322

4

.364

linear by linear association

1.411

1

.235

N of valid cases

159

a. 4 cells (44.4%) expected counting lower than 5. The minimum expected counting is .40.

Figure 6 – Results regarding to the splinting extension in function of the graduation time

Through Chi-square test, with p = 0,422, no association was verified between the graduation time and the splinting extension.

28 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

would do nothing

Counting % inside the time

6 5.4%

3 9.7%

1 6.3%

would only replant

Counting % inside the time

54 48.2%

12 38.7%

7 43.8%

replantation + endodontics

Counting % inside the time

20 17.9%

8 25.8%

7 43.8%

replant+surface treat+ endodontics

Counting % inside the time

32 28.6%

8 25.8%

1 6.3%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Asymp sig (2-sided)

Pearson’s chi-square

8.437a

4

.208

Likelihood ratio

8.697

4

.191

linear by linear association

.480

1

.489

N of valid cases

159

a. 4 cells (33.3%) expected counting lower than 5. The minimum expected counting is 1.01

Figure 7 – Results regarding to the procedure performed 2 hours after the avulsion in function of the graduation time

Through Chi-square test, with p = 0.208, no association was verified between the graduation time and the response on the procedure performed 2 hours after the avulsion.

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

extra-alveolar time

Counting % inside the time

59 52.7%

19 61.3%

11 68.8%

periodontal ligament condition

Counting % inside the time

13 11.6%

2 6.5%

2 12.5%

rhizogenesis stage

Counting % inside the time

6 7.1%

2 6.5%

2 12.5%

storage

Counting % inside the time

32 28.6%

8 25.8%

1 6.3%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test

Pearson’s chi-square

Value

df

Asymp sig (2-sided)

4.797a

6

.570 (Continues on the next page)

29 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

Likelihood ratio

5.801

6

.446

linear by linear association

2.456

1

.117

N of valid cases

159

a. 5 cells (41.7%) expected counting lower than 5. The minimum expected counting is 1.21

Figure 8 – Results regarding to the most important factor for replantation success in function of the graduation time

Through Chi-square test, with p = 0.570, no association was seen between the graduation time and the response on the most important factor for replantation success.

Time

Situation

Up to 5 years

5 to 10 years

More than 10 years

would replant the tooth

Counting % inside the time

37 33%

7 22.6%

3 18.8%

would not replant the tooth

Counting % inside the time

75 67%

24 77.4%

13 81.3%

Counting % inside the time

112 100%

31 100%

16 100%

Total

Chi-square test Value

df

Asymp sig (2-sided)

Pearson’s chi-square

2.273a

2

.321

Likelihood ratio

2.381

2

.304

linear by linear association

2.154

1

.142

N of valid cases

159

a. 1 cell (16.7%) expected counting lower than 5. The minimum expected counting is 4.73

Figure 9 – Results regarding to execution of primary tooth replantation in function of the graduation time

Through Chi-square test, with p = 0.321, no association was verified between the graduation time and the response on the primary tooth replantation.

Discussion The care provided immediately or the first care attitudes to the patient injured with dentoalveolar trauma, especially in cases of avulsed teeth, can decide either the success or failure in clinical prognosis [24]. Therefore, it is necessary that the population and health professionals are better informed on the emergency care for these types of injuries.

Thus, this study was conducted with a group of graduate students in dentistry in order to verify the knowledge on avulsion treatment, similarly to the studies of Kostopoulou and Duggal [16], França

et al. [12], Westphalen et al. [29], Vasconcellos et al. [28], and Zhao and Gong [31], who also applied a questionnaire to dentists.

The definition of the target group was based on the fact that the dentists educate and make the population aware about this subject.

Although 81.13% of the participants never treated an avulsion case, – as observed in the study of Pacheco et al. [23] in which 88.3% of the professors never treated tooth avulsion and Mori et al. [21] with 77% –, of the 159 graduates answering the questionnaire, 99.37% reported they had already received instruction on tooth avulsion,

30 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

corroborating the studies of Díaz et al. [9] and Krastl et al. [17].

Concerning to the treatment of the socket of the avulsed tooth, most of the respondents only would clean it with saline solution. This information was also observed in the study of Vasconcellos et al.

[28], in which 64.1% of the dentists would also clean the tooth socket.

With regard to the splinting type, although without statistically significance in relation to the graduation time, most of the dentists would execute the semi-rigid splinting, similarly to the studies of Westphalen et al. [29] (73%) and Vasconcellos et al. [28] (82.2%). On the other hand, in the study of Zhao and Gong [31], of the 258 dentists, 49% would use rigid and 45.1% semi-rigid splinting.

According to Diangelis and Bakland [8], Flores et al. [11] and Trope [27], semi-rigid splinting favors pulp and periodontal healing and stabilizes the tooth during the healing period, providing the regeneration of the periodontal ligament, consequently reducing the chances for ankylosis and resorption.

In this present study, no difference was seen between splinting time for 15 and 30 days. This was also verified by the studies of Kostoupoulou and Duggal [16], Westphalen et al. [29],and Vasconcellos et al. [28].

Accordi ng to A ndreasen a nd A ndreasen [4], a period of one week is enough to assure a proper periodontal support because the gingival fibers would be already repaired within this time interval.

Concerning to the most important factor for replantation success, most of the students identified the extra-alveolar time, similarly to the study of Zhao and Gong [31], in which 78.8% of the dentists considered the time factor as mandatory for the success of avulsion cases.

The survival of the periodontal ligament present on the root surface is related to short extra-alveolar period and several studies [6, 15, 30] have reported this as the most important factor for replantation success. When the tooth is not replanted at the time of avulsion, the patient should be instructed to store it in appropriate media and search a dentist as soon as possible. The storage, according to Trope [27], aims at minimizing the post-replantation inflammatory response because it avoids dryness and keeps the periodontal ligament cell viability for longer time.

In the case of avulsed teeth with complete root formation that remained in dry medium for more than 2 hours, the treatment of choice consists in

removing the periodontal ligament of the tooth, treating the root surface, performing the endodontics prior to replantation [26, 27].

With regard to the replantation of primary teeth, the vast majority of dentists would not replanted the tooth in its socket, which agrees with the data obtained in the studies of Cohenca et al. [7] (85.3%), Al-Asfour et al. [1] (71%), and Zhao and Gong [31] (87.1%).

According to the American Academy of Pediatric Dentistry [3], the replantation of avulsed primary teeth is contraindicated due to possible consequences for the development of the permanent tooth.

Conclusion Based on the results obtained, it could be verified a variability of opinion on the subject. It is important to highlight that although 99.37% of the participants had already been instructed on the treatment of avulsed teeth during graduation, their knowledge could be improved regardless of the graduation time.

References 1. Al-Asfour A, Andersson L, Al-Jame Q. School teachers’ knowledge of tooth avulsion and dental first aid before and after receiving information about avulsed teeth and replantation. Dent Traumatol. 2008 Feb;24(1):43-9.

2. Al-Obaida M. Knowledge and management of traumatic dental injuries in a group of Saudi primary schools teachers. Dent Traumatol. 2010 Aug;26(4):338-41.

3. American Academy of Pediatric Dentistry.

Clinical guideline on management of acute dental trauma. Manual de referência – ano 2004/2005.

4. Andreasen JO, Andreasen FM. Texto e atlas colorido de traumatismo dental. 3. ed. Porto Alegre: Artmed; 2001.

5. Andreasen JO, Lauridsen E, Gerds TA, Ahrensburg SS. Dental trauma guide: a source of evidence-based treatment guidelines for dental trauma. Dent Traumatol. 2012 Oct;28(5): 345-50.

6. Boyd DH, Kinirons MJ, Gregg TA. A prospective study of factors affecting survival of replanted permanent incisors in children. Int J Pediatric Dent. 2000 Sep;10(3):200-5.

31 – RSBO. 2015 Jan-Mar;12(1):23-31 Melo and Couto – Evaluation of graduate dental students’ knowledge on the therapeutic approach of dental avulsion

7. Cohenca N, Forrest JL, Rotstein I. Knowledge of oral health professionals of treatment of avulsed teeth. Dent Traumatol. 2006 Dec;22(6):296-301.

8. Diangelis AJ, Bakland LK. Traumatic dental injuries: current treatment concepts. J Am Dent Assoc. 1998 Oct;129(10):1401-14.

9. Díaz J, Bustos L, Herrera S, Sepulveda J. Knowledge of the management of paediatric dental traumas by non-dental professionals in emergency rooms in South Araucania, Temuco, Chile. Dent Traumatol. 2009 Dec;25(6):611-9.

10. Fernandes AV. Programa “Salve um dente”: reimplante dentário. Rev CROMG. 1995 Fev;1(1):37-9.

20. Miranda ACE, Habitante SM, Candelária LFA. Revisão de determinados fatores que influenciam no sucesso do reimplante dental. Rev Biociênc Unitau. 2000 Jan/Jul;6(1):35-9.

21. Mori GG, Castilho LR, Nunes DC, Turcio KH, Molina RO. Avulsion of permanent teeth: analysis of the efficacy of an informative campaign for professionals from elementary schools. J Appl Oral Sci. 2007 Dec;15(6):534-8.

22. Oliveira TM, Sakai VT, Moretti AB, Silva TC, Santos CF, Machado MA. Knowledge and attitude of mothers with regards to emergy management of dental avulsion. J Dent Child. 2007 SepDec;74(3):200-2.

11. Flores MT, Andreasen JO, Bakland LK, Feiglin B, Gutmann JL, Oikarinen K et al. Guidelines for the evaluation and management of traumatic dental injuries. Dent Traumatol. 2001 Apr;17(2):49-52.

23. Pacheco LF, Filho PF, Letra A, Menezes R, Villoria GE, Ferreira SM. Evaluation of the knowledge on the treatment of avulsions in elementary school teachers in Rio de Janeiro, Brazil. Dent Traumatol. 2003 Apr;19(2):76-8.

12. França RI, Traebert J, Lacerda JT. Brazilian dentists’ knowledge regarding immediate treatment of traumatic dental injuries. Dent Traumatol. 2007 Oct;23(5):287-90.

24. Pohl Y, Filippi A, Kirschner H. Results after replantation of avulsed permanent teeth. I. Endodontic considerations. Dent Traumatol. 2005 Apr;21(2):80-92.

13. Fujita Y, Shiono Y, Maki K. Knowledge of emergency management of avulsed tooth among Japanese dental students. BMC Oral Health. 2014 Apr 8;14(1):34.

25. Santos ME, Habecost AP, Gomes FV, Weber JB, Oliveira MG. Parent and caretaker knowledge about avulsion of permanent teeth. Dent Traumatol. 2009 Apr;25(2):203-8.

14. Ghaderi F, Adl A, Ranjbar Z. Effect of a leaflet given to parents on knowledge of tooth avulsion.

Eur J Paediatr Dent. 2013 Mar;14(1):13-6.

26. Trope M. Treatment of the avulsed tooth.

Pediatric Dent. 2000 Mar-Apr;22(2):145-7.

15. Kenny DJ, Barrett EJ, Casas MJ. Avulsions and intrusions: the controversial displacement injuries.

J Can Dent Assoc. 2003 May;69(5):308-13.

16. Kostopoulou MN, Duggal MS. A study into dentists’ knowledge of the treatment of traumatic injuries to young permanent incisors. Int J Paediatr Dent. 2005 Jan;15(1):10-9.

17. Krastl G, Fillipi A, Weiger R. German general dentists’ knowledge of dental trauma. Dent Traumatol. 2009 Feb;25(1):88-91.

18. Lieger O, Graf C, El-Maaytah M, Von Arx T. Impact of educational posters on the lay knowledge of school teachers regarding emergency management of dental injuries. Dent Traumatol.

2009 Aug;25(4):406-12.

19. Mesgarzadeh AH, Shahamfar M, Hefzollesan A. Evaluating knowledge and attitudes of elementary school teachers on emergency management of traumatic dental injuries: a study in an Iranian urban area. Oral Health Prev Dent.

2009;7(3):297-308.

27. Trope M. Clinical management of the avulsed tooth: present strategies and future directions.

Dent Traumatol. 2002 Feb;18(1):1-11.

28. Vasconcellos LG, Brentel AS, Vanderlei AD, Vasconcellos LM, Valera MC, Araújo MA. Knowledge of general dentists in the current guidelines for emergency treatment of avulsed teeth and dental trauma prevention. Dent Traumatol.

2009 Dec;25(6):578-83.

29. Westphalen VP, Martins WD, Deonizio MD, Silva Neto UX, Cunha CB, Fariniuk LF. Knowledge of general practitioners dentists about the emergency management of dental avulsion in Curitiba, Brazil.

Dent Traumatol. 2007 Feb;23(1):6-8.

30. Wong KS, Sae-Lim V. The effect of intracanal Ledermix on root resorption of delayedreplanted monkey teeth. Dent Traumatol. 2002 Dec;18(6):309-15.

31. Zhao Y, Gong Y. Knowledge of emergency management of avulsed teeth: a survey of dentists in Beijing, China. Dent Traumatol. 2010 Jun;26(3):281-4.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):32-40

Original Research Article

Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation Simone Scandiuzzi Francisco1 Adriana de Jesus Soares2 Rodrigo Dutra Murrer1 Corresponding author: Simone Scandiuzzi Francisco Rua João Francisco Sampaio, s/n, Cond. Terra dos Kariris, casa 1 CEP 63180-000 – Barbalha – CE – Brasil E-mail: simonescan@gmail.com 1 2

Dentistry Course, Leão Sampaio School – Juazeiro do Norte – CE – Brazil.

São Leopoldo Mandic School – Campinas – SP – Brazil.

Received for publication: February 28, 2014. Accepted for publication: September 2, 2014

Keywords: dental trauma; education health; dental avulsion.

Abstract Introduction: Dental trauma care emergency is very important issue, especially in cases of avulsion and it is crucial for the prognosis.

A preventive-educational approach had not been effective and there are many failures in handling dental trauma, mainly by lack of knowledge by health professionals, teachers and lay people. Objective: The aim of this study was to assess the knowledge of 89 teachers about dental trauma. Material and methods: A questionnaire divided into three parts containing questions about the emergency procedures in cases of dental trauma was applied. Results: Only 13% of teachers would replant the tooth in the socket, and only 7% said they would put the tooth in some liquid and 58% would store in a piece of paper, cloth or clean container. In relation to replantation, 75% reported that they would hold the tooth by the crown, 79% reported that first they would refer to the dentist, and 80% thought that the treatment had to be immediate. With regard to tooth preparation, 46% would keep it in saline, 24% in water, and only 11% in milk. Concerning to the avulsed tooth, only 15% correctly answered that they would replant the avulsed tooth and then referred to the dentist. Conclusion: It was concluded that the knowledge of teachers must be improved by educational and preventive campaigns on management of traumatized teeth.

33 – RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. – Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation

Introduction The Dentistry prioritizes the maintenance and integrity of teeth in the mouth, and the occurrence of dental trauma is difficult to reach this target, since its consequences involve functional, aesthetic, psychological, social and therapeutic damage, in addition to high costs for rehabilitation and monitoring for long periods of time [7, 17, 24].

In the presence of dental trauma, the oral structures are damaged on impact, which may cause changes in pulp and periodontal tissues, requiring a n adequate emergency ca re a nd t reat ment.

Treatment may be only the diagnosis of pulp and periodontal status, requiring palliative conduct to more complex treatments, in order to keep the tooth in a position to perform normal functions. The most common traumatic dental injuries are crown fractures involving enamel and enamel / dentine, but some injuries may be more serious, such as dental avulsion and intrusion, which require urgent immediate care as they could generate irreversible damage to the pulp and periapical tissues, leading to tooth loss [9].

Traumatic lesions such as crown fractures have a favorable prognosis for maintaining the vitality of the pulp compared with complicated crown fractures. The crown fracture not always develops pulp changes as obliteration of the canal or necrosis, however, when associated with tooth luxation, presents a significant deleterious effect on pulp prognosis, developing endodontic complications [7]. On the other hand, the root fractures involve a combination of damage to the periodontal ligament, cementum, dentin, and pulp which are results from frontal impacts that force the tooth crown to the palatal region and the apical root portion labially.

There is a more favorable prognosis when there is no compromise of the integrity of the pulp and periapical tissues, with the control of mobility and maintenance of pulp vitality of the fragments [9].

In periodontium, when low intensity impacts occur, small resorptions may develop whose prognosis is favorable because the newly formed cementum promotes repair. Most severe impacts results in luxations that cause periodontal ligament rupture, leading to tooth extrusion and even avulsion or intrusion by the impaction of the tooth in the socket.

Tooth luxation comprises the injuries that affect the periodontal ligament whose injury severity increases according to the tooth displacement after the impact. The lesions such as concussion and subluxation are those that cause no movement of the teeth, while the lateral luxation and extrusion, intrusion, and avulsion are those in which there

is a large displacement of the tooth in the socket developing immediate or late complications, which favors the development of pulp necrosis and resorption [9].

Tooth avulsion is the complete removal of the tooth out of the socket and is considered a serious injury, which generates damage often irreversible with aesthetic and functional impairment, and may even lead to tooth loss, which directly affects the self-esteem and interpersonal relationship among people [1, 6, 14]. The prevalence is 0.5% to 16%, involving children between 7 and 15 years of age, in whom the incidence is higher in upper central incisors [7]. The treatment for avulsed teeth is the immediate dental replantation in an attempt to reinstate it to its original anatomical position, maintaining the function and integrity [8]. Therefore, emergency care is crucial in trying to keep the tooth. Thus, the chances of replantation depend on an immediate response of the person injured in performing their own replantation or persons who are at the scene. And in cases where it is not possible to perform immediate replantation, management of injured teeth is equally important in order to maintain viable periodontal ligament fibers. In cases of tooth extraction, the shorter tooth staying out of the socket, the better the chances of success. The time from trauma to the tooth repositioning predisposes the development of complications, directly influencing the prognosis, making it unfavorable [7].

Currently, there is an increase of traumatic injuries among children and adolescents. Accidents occur mainly at home, on the streets and in schools, because of the type of play and the large number of activities and sports practices involving various modalities [7]. For a good prognosis of traumatic injuries agility and knowledge about treatment are important, together with necessary information on the management of traumatic accidents for people who deal daily with children and adolescents, as well as to the lay population.

Studies on the knowledge of health professionals a nd teachers have demonst rated t he lack of knowledge on the management of traumatic injuries in permanent and deciduous teeth [3, 11, 13, 22-24, 27, 31, 32, 34]. Thus, this study aims to verify the primary education teachers' knowledge working at private and public schools about the steps to be taken after the occurrence of dental trauma.

Material and methods This study was submitted and approved by the Ethical Committee in Research of the UniEvangélica University Center (Anápolis – GO). The professors

34 – RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. – Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation

aged from 18 to 65 years were randomly evaluated and were willing in answering the questionnaire on the knowledge about the care after tooth trauma.

A specific questionnaire was distributed for private and public primary schools.

The questionnaire was modified according to other studies in the literature [12, 26, 31], divided into three parts: part 1 verified the personal data of the professor; the part 2 dealt with the emergency care of tooth trauma, tooth avulsion experience; and what they would do facing tooth avulsion; part 3 assessed the professors’ approach towards simulated tooth trauma situations. The answers were tabulated and presented as percentages.

Results Eighty-nine professors participated in the study from private (46) and public (43) schools. All of

them responded a questionnaire on tooth trauma.

Part 1 comprised the personal and professional characteristics regarding age, gender, education level, professional experience, and instruction on first-aid care and tooth trauma (table I). Part 2 was composed of basic questions on the importance of emergency situations, experience on tooth avulsion and which attitude toward the child experiencing tooth avulsion (tables II and III). Part 3 evaluated the knowledge through simulating clinical cases of tooth fracture and avulsion.

Most of the participants were female (83%), aged from 20-39 years (62%), with high education (84%), and professional expertise of 5-15 years (41%). About 47% of the professors received firstaid training, 98% were not instructed about tooth trauma, and 78% reported they did not know this subject. Of all professors, 96% would like to be instructed on tooth trauma (table I).

Table I – Frequency distribution according to gender, age, educational level of the primary education teachers of the schools of Anápolis (GO)

Gender F 74 (83%)

M 15 (17%)

Total 89

% (100%)

M 0% 6 (40%) 4 (26.5%) 4 (26,5%) 1 (7%) 15 (100%)

Total 4 28 28 21 8 89

% 4% 31.5% 31.5% 24% 9% 100%

Educational level F M 1 (1%) 0 (0%) 62 (84%) 11 (73%) 11 (15%) 4 (27%) 74 (100%) 15 (100%)

Total 1 73 15 89

% 1% 82% 17% 100%

Age Below 20 years 20 to 29 years 30 to 39 years 40 to 49 years More than 50 years General total

Full secondary education Full higher education Incomplete higher education General total

F 4 (5%) 22 (30%) 24 (32%) 17 (23%) 7 (10%) 74 (100%)

Part 2 demonstrated the lack of experience of the professor regarding to tooth trauma, because only 19% faced some case, and 79% would not replanted the avulsed tooth. Notwithstanding, if they had to replant, 75% would touch the tooth by the crown and 55% would wash the tooth in running water in case of dirty (table II).

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Table II – Frequency distribution of the emergency care of the primary education professors of the schools of Anápolis (GO) towards tooth avulsion and replantation

Suppose that you decide to put it back, but the tooth fell to the ground and it is covered by dirty, what would you do?

Brush the tooth gently with a toothbrush

6

7%

Wash the tooth in plenty running water

49

55%

Put the tooth back into the socket without doing nothing

0

0%

Do not know what to do

21

24%

Wash the tooth in water and soap

2

2%

Throw the tooth in convenient waste to prevent contamination

4

4%

Did not respond

3

3%

Answered more than one alternative: Brush the tooth gently and wash in running water

4

4%

89

100%

General total

During the placement of the tooth back in its socket, how do you hold the tooth?

By the crown

67

75%

By the root

4

4%

Either way (crown or root)

4

4%

Did not respond

14

16%

General total

89

100%

Concerning to the storage of the avulsed tooth, 58% of the professors would store it in dry environment, such as the student’s hand, piece of paper or cloth, clean plastic flask; only 3% would place it inside the student’s mouth and 7% would store it in wet environment. With regard the storage medium, 46% would use saline solution, 24% running water, and 11% milk (table III).

Table III – Frequency distribution of the emergency care of the primary education professors towards the storage of avulsed teeth

If you had not put the tooth back into its socket, how would you carry it to be taken to the dentist?

Inside ice

23

26%

Inside any liquid

6

7%

Inside the student’s mouth

3

3.5%

On the student’s hand

2

2%

On a clean pape ror cloth

26

29%

Inside a clean plastic flask

24

27%

Did not respond

2

2%

Responded more than one alternative

3

3.5%

89

100%

General total

36 – RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. – Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation

Table III (continued)

If you had used a liquid to carry the tooth, which one would you choose?

Running water Fresh milk Student’s saliva Alcohol Juice Saline solution Antiseptic solution Did not respond Responded more than one alternative General total Also, in case of tooth avulsion, 79% of the participants would refer the patient to a dentist and 80% considered that immediate treatment must be provided. Concerning to primary tooth, 52% reported that they knew how to differentiate a primary from permanent tooth, 16% indicated that the primary tooth should be replanted, and 47% did not know if the primary tooth should or should not be replanted. About 51% of the professors reported that they would search about tetanus vaccination, 37% reported that they would give medicaments to the child in case of pain after tooth trauma; of these, 82% would give analgesic drug, 12% anti-inflammatory drug, and 6% both analgesic and anti-inflammatory drugs.

Part 3 hypothetically simulated two tooth trauma situations to evaluate the attitude and knowledge of the professors, following the questionnaire of the clinical cases of tooth trauma. In case 1, we verified which the best attitude to be taken by the professors facing the following case: 9-year-old child fell down and hit the face, broking the front tooth, without injury and loss of consciousness.

About 62% knew how to differentiate the maxillary permanent tooth involved in the case on enamel/ dentin fracture, 20% thought that the traumatized tooth was primary and 18% did not know how to answer. With regard to the immediate approach, 84 (94%) answered that first, they would call the parents and instruct to seek a dentist; of these only 42 answered that they would also search for pieces of the broken tooth.

In case 2, we verified which would be the best attitude of the professors towards the following case: 12-year-old girl fell from the stairs and injured the mouth with bleeding and tooth avulsion. Only 13 (15%) reported they would replant the tooth and send the child to the dentist immediately. About 61 (69%) professors answered that they would store the tooth in some liquid and refer the child to the dentist immediately.

21 10 1 4 5 41 2 1 4 89

24% 11% 1% 4% 6% 46% 2% 1% 4% 100%

Discussion During the last decades, several studies have been published with worrying results regarding the lack of knowledge about dental trauma and management of traumatized teeth, both by lay people and health professionals [1-4, 10, 12, 13, 15, 18-23, 27, 29, 31, 32, 34, 37, 38]. The results of this study confirmed the lack of knowledge about dental trauma in the training of elementary school teachers, similarly to international [2, 12, 25] and Brazilian [27, 31, 32] studies. During the academic training of teachers, 47% had first aid training that not addressed the issue of dental trauma and 78% of teachers were unaware of it. This is worrisome because the school is considered an important and potentially favorable site to the occurrence of dental trauma for the children involved in physical activities and social [36]. This result leads to the perception that the inclusion of this issue on first aid orientation during the pedagogical training of teachers is required.

Several factors also influence on the prognosis of avulsed teeth, such as trauma extension, extraalveolar time, handling and contamination of avulsed teeth, and storage medium [7]. Tooth reimplantation success varies between 4% and 50%. This disparity is attributed to the conditions of the teeth and diversity of treatments. The literature recommends that avulsed teeth are immediately replanted because of the fragility of the periodontal ligament cells (PL) [7, 16]. About 80% of the teachers answered correctly that the tooth should be replanted immediately and the dentist would be the first professional of choice, only 13% would replant the tooth. For measures to be taken in cases of tooth extraction, 24% of the respondents said they did not know what to do to help the child and 70% said they would not replanted the tooth. In this study there was a low rate of dental replantation, as in other studies in the

37 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. â&#x20AC;&#x201C; Evaluation of elementary education teachersâ&#x20AC;&#x2122; knowledge on avulsion and tooth replantation

literature [4, 12]. Although 75% of teachers answer correctly that the avulsed tooth should be handled by the crown and 55% respond that would wash in running water abundantly, few would realize the dental reimplantation.

A short extra-alveolar length time is best for the preservation of avulsed teeth, because of the development of the few areas of root resorption. In 1990, Andersson and Bodin [5] investigated human teeth replanted after 15 minutes and observed that most of the teeth had preserved its integrity and is recommended reimplantation as soon as possible.

However, it is not always possible that the tooth is replanted just after avulsion, so that tooth must be properly stored [7].

The storage medium is a major factor influencing the prognosis of dental replantation because the tooth must be kept in a medium in which the pH, osmolarity and metabolism are physiologically compatible with the vitality of LP cells present on the root and in some cases even to stimulate its proliferation. The primary means of transport are: water, milk, physiological saline, Hank's balanced salt solution, ViaSpan and saliva.

Currently milk is considered one of the best storage medium because of their ideal physiological properties for maintaining the LP vitality for up to 6 hours, in addition to its easy access at the time of the accident, providing an adequate medium until searching for a dentist [7, 8, 27]. In this study, for the storage, 58% of teachers would store the tooth on a piece of paper, clean cloth, clean plastic or hand of the student, that is, in a dry environment.

In the case of transporting in liquid medium, only 11% knew that milk is the best storage medium, 46% would store in saline and 24% water. The lack of knowledge on the storage medium and dental replantation has been reported by previous studies [12, 27, 31].

Of the most frequent traumatic dental injuries, crown fractures involving enamel and enamel/ dentine are those that most affect young people [7, 14]. Evidence shows the negative impact of dental trauma among teenagers, because the smile's appearance plays an important role in the composition of facial aesthetics and the presence of traumatic injuries can hinder social interaction of individuals affected [14]. The dental trauma involves several cosmetic changes, in addition to dental fracture it may result in color change of teeth, tooth mobility, pulp pathologies and pain.

The restoration of a fractured tooth must have a satisfactory level in relation to aesthetics, because even in cases of simple fractures, there is need for

appropriate follow-up, since the prognosis of crown fractures depends not only on an accurate diagnosis, but also on appropriate restorative procedures [30]. The treatment of traumatic dental injuries is an important health promotion strategy that can significantly prevent negative biological and social impacts [19, 33].

In the clinical case describing the crown fracture, about 62% of the teachers recognized that the incisor tooth is one of the permanent dentition in a 9 year-old child and 94% said they first come into contact with parents and would advise to look for the dentist; of these, 47% said they also seek the pieces of the broken tooth. Although most teachers consider important to refer to the dentist, is still low the number of teachers who seek the dental fragment, showing lack of proper care. Also in relation to the first case, 52% said they knew the difference between a primary from a permanent tooth. This is worrisome because the emergency treatment for primary teeth, especially in cases of avulsion, is not the replantation, to avoid compromising the development of permanent tooth [16].

In the case in which the child suffered tooth avulsion, only 15% reported that they would place the tooth back in its place and would take the child to the dentist immediately. The time between avulsion of the tooth and its replantation is considered of paramount importance for the prognosis of the avulsed tooth. Often lay people do not have proper evaluation of how critical this period is. Over time, the periodontal ligament cells adhered to tooth will necrotizing rapidly and success rate decreases vertically. Extra-alveolar periods longer than two hours almost always determine intense resorptions and therefore a poor prognosis [8].

In cases of av ulsion, it is recommended prophylactic administration of tetanus vaccine and antibiotics because of tooth infection and also to prevent inflammatory resorption [7, 9, 16]. In this study, 51.0% of teachers reported that they would investigate about the tetanus vaccination and 37% reported that they would give medications to the child in case of pain after suffering dental trauma, with the analgesic being the drug of choice, similar to other studies. Although the analgesic drug is beneficial in aiding the pain relief, the drug prescription by lay people should not be performed because of the possibility of occurrence of allergy or even drug interactions.

This study revealed that most teachers were not able to make the correct emergency care and did not receive adequate training on this.

38 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. â&#x20AC;&#x201C; Evaluation of elementary education teachersâ&#x20AC;&#x2122; knowledge on avulsion and tooth replantation

W hereas a favorable prognosis for av ulsed / replanted depends significantly on the triad time the tooth remained outside the mouth, storage and appropriate transport medium, and minimal aggression to the root surface, knowledge of the emergency care of traumatic injuries is essential for tooth reestablishment and permanence in the mouth [19, 29, 32, 35].

Lay people, such as teachers and parents, are usually present at the time of the accident and may be the first to provide initial care. Nevertheless, several studies show the unpreparedness of them to properly handle the situation [19, 22, 23, 29].

According to Al-Asfour et al. [2], a lecture followed by discussion seems to be an efficient method to increase the knowledge and management of traumatic injuries. Following administration of a lecture, the authors found that there was an improvement of 39% to 97% in the general knowledge of avulsion. Given the above, it is highlighted the need for multidisciplinary interaction between health professionals (dentists, doctors, nurses) and teachers, who are information multipliers. So, there will be a positive interaction in health promotion and prevention of post-traumatic complications.

Halawany et al. [19] found that well-qualified teachers are better able to make the right decisions in the management of emergencies related to tooth avulsion.

Mori et al. [26] obtained positive results after conducting an educational campaign, with leaflets, posters and lectures for health promotion and expansion of knowledge about dental trauma for professionals in schools. Thus, the use of clear and simple information is one of the best ways to improve the treatment success of avulsed permanent teeth and emergency management of traumatic injuries.

It is essential to implement public health policies that enable the reduction in the prevalence of traumatic dental injuries through legislation, prevention and education. More efforts are needed to expand the knowledge related to the promotion and maintenance of health, with parents, teachers and professionals the main people involved. One of the strategies for health promotion related to dental trauma is the expansion and recognition by health professionals and the general public that traumatic injuries can be prevented when associated with education campaign on dental trauma in schools and in the community. Health professionals can contribute in this sector through information and awareness of the importance of the use of

mouthguards during sports and in treating dental trauma by correctly registering the place, time, cause, and human intention. Thus, we can identify acts of violence, whose information can contribute to the responsible agencies in the development of an individual protection efficient policy. The school environment is considered a suitable place to start an education program in oral health and dental trauma prevention , because more than one billion children are present in schools all over the world, in addition to teachers, school employees, students of parents and community involved.

Programs of prevention and health promotion can strengthen, throughout the school life of children, basic health concepts to improve self-esteem, social behaviors, and life skills. In addition, these programs can humanize the school environment and implement policies and practices that offer multiple opportunities for health [28]. Educational campaigns to prevent accidents involving dental trauma should be instituted in order to minimize the damage caused by traumatic injuries.

Conclusion Based on the analysis of the data, it was concluded that there are many failures in the management of dental trauma, mainly by the lack of knowledge and, therefore, development of instruction programs for elementary school teachers and staff on emergency procedures in cases of trauma and tooth extraction should be consider.

References 1. Abu-Dawoud M, Al-Enezi B, Andersson L. Knowledge of emergency management of avulsed teeth among young physicians and dentists. Dent Traumatol. 2007;23(6):348-55.

2. Al-Asfour A, Andersson L, Al-Jame Q. School teachers' knowledge of tooth avulsion and dental first aid before and after receiving information about avulsed teeth and replantation. Dent Traumatol. 2008;24(1):43-9.

3. Al-Jundi SH. Knowledge of Jordanian mothers with regards to emergency management of dental trauma. Dent Traumatol. 2006;22(6):291-5.

4. Andersson L, Al-Asfour A, Al-Jame Q. Knowledge of first-aid measures of avulsion and replantation of teeth: an interview of 221 Kuwaiti schoolchildren.

Dent Traumatol. 2006;22(2):57-65.

39 – RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. – Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation

5. Andersson L, Bodin I. Avulsed human teeth replanted within 15 minutes – a long-term clinical follow-up study. Endod Dent Traumatol.

1990;6(1):37-42.

17. Frujeri ML, Costa Jr ED. Effect of a single dental health education on the management of permanent avulsed teeth by different groups of professionals.

Dent Traumatol. 2009;25(3):262-71.

6. Andreasen JO. Luxation of permanent teeth due to trauma. A clinical and radiographic followup study of 189 injured teeth. Scand J Dent Res. 1970;78(3):273-86.

18. Fujita Y, Shiono Y, Maki K. Knowledge of emergency management of avulsed tooth among Japanese dental students. BMC Oral Health.

2014;14(1):34.

7. Andreasen JO, Andreasen FM. Textbook and color atlas of traumatic injuries to the teeth. 3. ed.

Copenhagen: Mosby; 1994.

19. Halawany HS, AlJazairy YH, Alhussainan NS, AlMaflehi N, Jacob V, Abraham NB. Knowledge about tooth avulsion and its management among dental assistants in Riyadh, Saudi Arabia. BMC Oral Health. 2014;14:46.

8. Andreasen JO, Borum MK, Jacobsen HL, Andreasen FM. Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing. Endod Dent Traumatol. 1995;11(2):76-89.

9. Araujo M, Valera M. Injúrias por luxação. In: Araujo M, Valera M (eds.). Tratamento clínico dos tramatismos dentários. São Paulo: Artes Médicas; 1999. p. 189-205.

10. Blakytny C, Surbuts C, Thomas A, Hunter ML. Avulsed permanent incisors: knowledge and attitudes of primary school teachers with regard to emergency management. Int J Paediatr Dent.

2001;11(5):327-32.

11. Caglar E, Ferreira LP, Kargul B. Dental trauma management knowledge among a group of teachers in two south European cities. Dent Traumatol.

2005;21(5):258-62.

12. Chan AW, Wong TK, Cheung GS. Lay knowledge of physical education teachers about the emergency management of dental trauma in Hong Kong. Dent Traumatol. 2001;17(2):77-85.

13. Cohenca N, Forrest JL, Rotstein I. Knowledge of oral health professionals of treatment of avulsed teeth. Dent Traumatol. 2006;22(6):296-301.

14. Cortes MI, Marcenes W, Sheiham A. Impact of traumatic injuries to the permanent teeth on the oral health-related quality of life in 12-14-year-old children. Community Dent Oral Epidemiol. 2002; 30(3):193-8.

15. De Franca RI, Traebert J, De Lacerda JT. Brazilian dentists' knowledge regarding immediate treatment of traumatic dental injuries. Dent Traumatol. 2007;23(5):287-90.

16. Flores MT, Andersson L, Andreasen JO, Bakland LK, Malmgren B, Barnett F et al.

Guidelines for the management of traumatic dental injuries. II. Avulsion of permanent teeth. Dent Traumatol. 2007;23(3):130-6.

20. Hu LW, Prisco CR, Bombana AC. Knowledge of Brazilian general dentists and endodontists about the emergency management of dento-alveolar trauma. Dent Traumatol. 2006;22(3):113-7.

21. Jorge KO, Ramos-Jorge ML, de Toledo FF, Alves LC, Paiva SM, Zarzar PM. Knowledge of teachers and students in physical education's faculties regarding first-aid measures for tooth avulsion and replantation. Dent Traumatol.

2009;25(5):494-9.

22. Karande N, Shah P, Bhatia M, Lakade L, Arora MNABN, Bhalla M. Assessment of awareness amongst school teachers regarding prevention and emergency management of dentoalveolar traumatic injuries in school children in Pune City, before and 3 months after dental educational program. J Contemp Dent Pract. 2012;13(6):873-7.

23. Kaur H, Kaur S, Kaur H. Prehospital emergency management of avulsed permanent teeth: Knowledge and attitude of school teachers. Indian J Dent Res. 2012;23(4):556.

24. Losso EM, Tavares MCR, Bertoli FMP, BarattoFilho F. Traumatismo dentoalveolar na dentição decídua. RSBO. 2011;8:e1-e20.

25. McIntyre JD, Lee JY, Trope M, Vann Jr WF. Elementary school staff knowledge about dental injuries. Dent Traumatol. 2008;24(3):289-98.

26. Mori GG, Castilho LR, Nunes DC, Turcio KH, Molina RO. Avulsion of permanent teeth: analysis of the efficacy of an informative campaign for professionals from elementary schools. J Appl Oral Sci. 2007;15(6):534-8.

27. Mori GG, Turcio KH, Borro VP, Mariusso AM. Evaluation of the knowledge of tooth avulsion of school professionals from Adamantina, Sao Paulo, Brazil. Dent Traumatol. 2007;23(1):2-5.

40 – RSBO. 2015 Jan-Mar;12(1):32-40 Francisco et al. – Evaluation of elementary education teachers’ knowledge on avulsion and tooth replantation

28. Moyses ST, Moyses SJ, Watt RG, Sheiham A. Associations between health promoting schools' policies and indicators of oral health in Brazil.

Health Promot Int. 2003;18(3):209-18.

29. Murali K, Krishnan R, Kumar VS, Shanmugam S, Rajasundharam P. Knowledge, attitude, and perception of mothers towards emergency management of dental trauma in Salem district, Tamil Nadu: a questionnaire study. J Indian Soc Pedod Prev Dent. 2014;32(3):202-6.

30. Olsburgh S, Jacoby T, Krejci I. Crown fractures in the permanent dentition: pulpal and restorative considerations. Dent Traumatol.

2002;18(3):103-15.

31. Pacheco LF, Filho PF, Letra A, Menezes R, Villoria GE, Ferreira SM. Evaluation of the knowledge of the treatment of avulsions in elementary school teachers in Rio de Janeiro, Brazil. Dent Traumatol. 2003;19(2):76-8.

32. Panzarini SR, Pedrini D, Brandini DA, Poi WR, Santos MF, Correa JP et al. Physical education undergraduates and dental trauma knowledge.

Dent Traumatol. 2005;21(6):324-8.

33. Ramos-Jorge ML, Peres MA, Traebert J, Ghisi CZ, de Paiva SM, Pordeus IA et al. Incidence of dental

trauma among adolescents: a prospective cohort study. Dent Traumatol. 2008;24(2):159-63.

34. Sae-Lim V, Lim LP. Dental trauma management awareness of Singapore pre-school teachers. Dent Traumatol. 2001;17(2):71-6.

35. Santos ME, Habecost AP, Gomes FV, Weber JB, Oliveira MG. Parent and caretaker knowledge about avulsion of permanent teeth.

Dent Traumatol. 2009;25(2):203-8.

36. Traebert J, Bittencourt DD, Peres KG, Peres MA, de Lacerda JT, Marcenes W. Aetiology and rates of treatment of traumatic dental injuries among 12-year-old school children in a town in southern Brazil. Dent Traumatol.

2006;22(4):173-8.

37. Traebert J, Traiano ML, Armenio R, Barbieri DB, de Lacerda JT, Marcenes W. Knowledge of lay people and dentists in emergency management of dental trauma. Dent Traumatol. 2009;25(3):27783.

38. Westphalen VP, Martins WD, Deonizio MD, da Silva Neto UX, da Cunha CB, Fariniuk LF. Knowledge of general practitioners dentists about the emergency management of dental avulsion in Curitiba, Brazil. Dent Traumatol. 2007;23(1):6-8.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):41-9

Original Research Article

Assessment of knowledge about oral cancer: study with students of public education Iara Fiorentin Comunello1 Elisabete Rabaldo Bottan1 Constanza Marín1 Eduardo Mazzetti Subtil2 Corresponding author: Elisabete Rabaldo Bottan Curso de Odontologia – Grupo de Pesquisa Atenção à Saúde Individual e Coletiva em Odontologia Universidade do Vale do Itajaí Rua Uruguai, n. 458 – Centro CEP 88302-202 – Itajaí – SC – Brasil E-mails: erabaldo@univali.br / erabaldo@gmail.com 1 2

Dentistry Course, University of Vale do Itajaí – Itajaí – SC – Brazil.

Medicine Course, University of Vale do Itajaí – Itajaí – SC – Brazil.

Received for publication: May 5, 2014. Accepted for publication: September 15, 2014.

Keywords: primary health care; oral neoplasm; disease prevention.

Abstract Introduction and Objective: To evaluate the level of knowledge about oral cancer of students attending public school in one city of Santa Catarina (Brasil). Material and methods: A descriptive crosssectional study, using primary data collection. Students of last year of elementary school and first year of high school, enrolled in public schools in the city of Itajaí (SC), in 2012, were the target population.

The non-probability sample was obtained by convenience. Data were collected through a self-administered questionnaire structured with 13 questions divided into three fields. The level of knowledge was made based on pre-established scores. Results: 1149 instruments were analyzed (80.8% of the target population). The average age of the group was 15.5 years and 54.5% were female. The majority (78%) never had received information about oral cancer. Only 27.9% had cognizance about self-examination of the oral cavity. With regard to knowledge, 87.5% classified as unsatisfactory. For most issues the cognitive field did not identify a significant correlation between knowledge and the variables gender and education. When asked if they would like to participate in educational and preventive activities

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about oral cancer and other issues related to health, 72.6% expressed interest. Conclusion: The group did not have adequate knowledge on the subject of oral cancer. Facing this reality, and the positive attitude of respondents, the researchers designed and offered an educational program to the research subjects.

Introduction Oral cancer, usually because of its treatment, can cause impairment in areas of the face, resulting in permanent dysfunction in essential activities for survival, such as feeding and socializing. This disease is considered a public health problem. In Brazil, it ranks the seventh place among all cancers diagnosed. To reverse this scenario, investment in public policies is necessary to support actions that lead to the reduction of morbidity and mortality for oral cancer [1, 3, 19, 24, 25].

The Primary Health Care (PHC) based on educational measures, governed by the principles of health promotion, is considered essential to the improvement of health indicators and the population's quality of life. Therefore, with respect to oral cancer, the early diagnosis can create opportunities better life condition to people [5, 8, 14].

The Declaration of Alma-Ata, synthesis document of the International Conference on Primary Health Care which took place in September 1978, already described minimum actions required to implement the primary health care to be developed in different countries. And among the actions, are those aimed at prevention and protection. Health education should be understood as a combination of opportunities that favor the maintenance and health promotion.

Educational practices should be designed to target the subjects’ autonomy in the conduct of their lives [1].

Thus, among social spaces that enable the promotion of the educational process in health care, it is understood that the school is a fundamental place. Therefore, health education programs in schools should be encouraged, involving students, teachers, health workers, parents, dentists, and other health professionals.

This research was based such assumptions, because it aimed to evaluate the knowledge level of scholars from the public schools of Itajaí (SC, Brazil) on oral cancer.

Itajaí is a city of Santa Catarina (Brazil), located at the north central coast of Santa Catarina. It occupies a land area of 288 km2, with a population of 183,373 inhabitants, resulting in a population

density of 636 inhabitants/km 2. The Municipal Human Development Index in 2010 was 0.795.

The territory space of the city is divided into 17 districts [9].

According to data from the Brazilian Institute of Geography and Statistics [9], in the city, in 2012, there were 12 public schools with high school, with a total enrollment of 6,092 students. And, there were ten public schools with basic education (5th to 9th grades), with 3,838 students. And among these schools, some offer both primary and secondary education.

The sociodemographic characteristics of Itajaí, together with its location (coastal region), justify the concern of the researchers on the prevention of oral cancer, so the results of this research are essential to the proposition of education-prevention activities aimed to these individual’s profile.

Material and methods The research is characterized as a descriptive, cross-sect iona l study t hrough prima r y data collection, which was conducted in Itajaí (SC, Brazil). The project was submitted and approved by the Ethics Committee in Research of Univali under protocol n. 171/11a.

To define the target population of the survey, only the students enrolled in 2012, at the last year of primary school and junior high first from 12 public schools located in nine districts were selected by raffle. According to records of the Department of Regional Development / Regional Education Management, the total number of enrolled students was 1,422.

To this target population, a non-probability sampling design was defined. The subjects were included in the study, since, after being informed about the research, they signed the Free and Clarified Consent Form (FCCF).

The instrument for data collection was a questionnaire with 13 open and closed ty pe questions. The questions were divided into three fields. The first field, with three questions of the closed type, referred to the sociodemographic characteristics of the sample. In the second field

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were included five types of closed type on attitudes of respondents regarding the educational-preventive process in relation to oral cancer. The third field contained five questions of closed type involving specific knowledge on the subject of oral cancer.

The instrument of data collection was pre-tested in 2.5% (n = 36) of the target population through a pilot study in order to assess the applicability of the questionnaire and the adequacy of the questions.

The pilot result denoted the need to reformulate t wo questions, which was performed. These questionnaires did not comprise the search.

D at a col le ct ion w a s p er for me d by t wo researchers, by defined schedule in agreement with the schools. In each group, the researchers provided explanations on the project and then gave the FCCF to those interested in participating, to express their agreement by signing it. Students below 18 years, in addition to signing the FCCF, also had their parents sign the FCCF. Only after this ethical care, the questionnaire was delivered, which was answered in the classroom, anonymously.

The assessment of the level of knowledge (field three of the questionnaire) was made based on the following scores: excellent – for a percentage of correct answers between 100% and 85%, satisfactory – for a percent of correct answers between 84% and 70%; regular – for a percentage of correct answers

between 69% and 60%; and unsatisfactory – for a percentage of correct answers less than 60%.

Data were tabulated with the aid of Excel software for Windows and submitted to descriptive statistics. To assess the association between the level of knowledge of the students and the variables sex and education, nonparametric test (Chi-square) was applied, with level of significance set at lower than 0.01 (p < 0.01).

Results 1,149 questionnaires fully completed returned, representing 80.8% of the target population.

The female subjects percentage was 54.5% (n = 626) and 45.5% were males (n = 523). The age of respondents ranged from 13 to 37 years, with mean age of 15.5 years.

Most of the respondents (78%; n = 896) claimed never received information about oral cancer. Among those who had received some instruction (n = 253), the main sources mentioned were: school, lectures, or content addressed in sciences/biology classes, and health professionals, with the dentist being the most cited (graph 1).

Graph 1 – Information source on oral cancer

A very low frequency (27.9%; n = 320) stated that they had heard about the self-examination of the oral cavity for the detection of signals that may be related to oral cancer. And among these subjects, only 17.5% (n = 56) had performed selfexamination.

When they were asked if they would like to participate in educational and preventive activities on oral cancer and other thematic related to health, the majority (72.6%; n = 834) showed interest. When inquiring about the strategies they considered important for the development of educational and preventive activities, most reported lectures (graph 2).

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Graph 2 – Strategies suggested for the developing of educative-preventive actions

Regarding the level of knowledge, the percentage of correct answers was very low, ranging from 3.8% to 13%, on the questions related to signs/ symptoms, location and age of occurrence of oral cancer (table I).

Table I – Frequency of the correct answers of cognitive domain

Question

Correct answers N %

Age range of most frequent occurrence of OC

44

Anatomic areas most affected

by OC

149

13.0

Most common signs of OC at initial phase

128

11.1

Alterations suspected as possible OC

of elementary school and junior high school), a significant association was found (p < 0.01), by Chi-square test, only to the question “What is the most frequent age of occurrence of oral cancer?” (table II), showing a better understanding of high school subjects, in this question.

Table II – Chi-square results for the ratio of correct answers in questions of the cognitive domain and the variables gender and the level of education

p value

3.8 Question

87

7.6

To this set of questions no significant association was found, by Chi-square test, between the level of knowledge (defined by the frequency of correct answers) and sex of respondents (table II). When we analyzed the association between level of knowledge and level of education (the last year

Age range of most frequent occurrence of OC Anatomic areas most affected by OC Most common signs of OC at initial phase Alterations suspected as possible OC *

Signifcante correlation

Knowledge X Sex

Knowledge X Education level

0.123

0.000*

0.133

0.238

0.134

0.264

0.693

0.401

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In the question of risk factors and cofactors related to ora l ca ncer, a mong t he 12 listed alternatives, only tobacco and poor oral hygiene items, the correct answer rate was just over 50% (table III).

Table IV – Chi-square results for the ratio of correct answers on the question on factors and cofactors and risk for oral cancer and the variables gender and education

Factors/Cofactors

Table III – Frequency of correct answers of each risk factor/cofactor for oral cancer

Factors/Cofactors

N

%

Excessive alcohol consumption

p value Knowledge Knowledge X X Education Sex level 0.0000* 0.1510 (1st gr) 0.0000* 0.0330 (2nd gr)

Excessive alcohol consumption

460

40.0

Tobacco consumption

746

64.9

Excessive consumption of spicy foods

85

7.4

Poor oral hygiene

692

60.2

Excessive exposure to sun

81

7.0

Prolonged consume of hot beverages and food

162

14.1

Use of poor adapted prostheses

270

23.5

Prolonged consume of hot beverages and food Use of poor adapted prostheses

Hereditary factors

184

16.0

Hereditary factors

0.9489

Low consume of fruits and vegetables

148

12.9

0.0008* (male)

0.0210

Fisherman, sailor and farmer

30

2.6

Low consume of fruits and vegetables Fisherman, sailor and farmer

0.1213

0.0000* (1st gr)

Pale skin

35

3.0

0.9780

485

42.2

0.0025* (female)

Use of oral piercing

The association between level of knowledge and sex and educational level was significant (p < 0.01), by Chi-square test in some of the items listed (table IV).

Tobacco consumption Excessive consumption of spicy foods Poor oral hygiene Excessive exposure to sun

Pale skin

0.4611

0.3531

0.0001* (female) 0.4103 0.6429

0.0000* (2nd gr) 0.3318 0.4162

0.3731

0.6765

0.1411

0.0000* (2nd gr) 0.0020* (1st gr)

The classification of the knowledge level of the group on oral cancer, according to the criteria established in this present study, was between regular and unsatisfactory, as it can be seen in graph 3.

Graph 3 – Criteria of the knowledge level of the study group

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Discussion The fight against cancer has been growing in recent years. However, unfortunately, all over the world, 50% of patients with oral cancer are at an advanced stage. Among the factors that may be associated to the problem and justify the high percentage of late diagnosis is: poor training in this area and population’s lack of knowledge about the disease [1, 3, 24, 25].

The understanding of the risk factors and cofactors, the natural history and epidemiology of oral mucosa lesions is essential to promote primary prevention, early diagnosis, and proper planning of health services. The guarantee of health education programs aimed at general population screening, appropriate treatment, and quality of life associated with the improvement of knowledge of health professionals on oral cancer are needed to reduce the morbidity and mortality resulting from this neoplasia [1, 3, 4, 7, 12, 16, 19, 20, 21, 26, 27].

The recognition, by the population, of the risk factors and cofactors, the most common signs and symptoms at the early stage of the disease, and the importance of early diagnosis, is essential to lower rates of cases of oral [1, 4, 5, 14, 19, 26].

However, in the population studied, the frequency of subjects that inform had received information, known, or have carried out self-examination of the oral cavity for the detection of signals that may be related to oral cancer was very low.

The assessment of knowledge of these subjects was seen as a motivating and mobilizing element of the target population as they noted the need to increase their knowledge on the subject of oral cancer and analyze the care they routinely engaged in oral health. Thus, we consider as a guiding principle of this research the Primary Health Care based on educational activities, governed by the principles of health promotion. Therefore, the discussion developed based on this perspective.

One aspect that should be highlighted is the age profile of the target population. Because they are young, it is considered that they are much more vulnerable to the action of environmental factors, especially those related to habits and lifestyles.

It is therefore unquestionably the importance of giving attention to this group and by analyzing which information they have in order to enhance educational and preventive activities.

On the literature reviewed, there is a consensus that the primary prevention of disease, through an educational process, can contribute to the awareness of the people. Knowledge influences the

behavior at all social levels of organization. Lack of awareness of individuals about signs, symptoms and risk factors associated with oral cancer is a powerful barrier to early detection [1-5, 7, 11, 13, 14, 16, 19-23, 26, 27].

The transmission of basic information can strengthen the population’s ability to deal with health problems. The acquired knowledge allows the subjects to be able to make choices that promote health or predispose to disease. In this context, knowledge about the development of malignancies is essential to prevention. Notwithstanding, researches have shown that there is a significant lack of knowledge of the population in general about the risk factors/cofactors for oral cancer [14, 16, 19, 21, 26, 27].

The results of this present study indicated that the knowledge of the respondents on the subject of oral cancer is unsatisfactory, confirming the findings reported in studies conducted in different contexts [14, 16, 19, 21, 26, 27]. It is noteworthy, in this study, the low percentage of correct answers on the factors associated with oral cancer, which are already established in the literature, such as sunlight, tobacco, and alcohol.

With regard to the consumption of tobacco and alcohol as risk factors associated with oral cancer, although they were the most cited by the subjects of this research, the rate of correct answers was low because fluctuated between regular and unsatisfactory levels. This result deserves attention because according to the Brazilian Survey on the Scholar Health [10], the higher frequency of experimentation of this two risk factors among adolescents was observed in the south region.

Concerning to exposure to sunlight and related conditions, such as certain professions and paleskin people who are part of the risk group for developing oral cancer, it was observed that few subjects that related that to oral cancer. This finding is very worrying, because the studied population lives in a coastal region.

The literature is consistent with regard to the etiology of oral cancer, noting that the disease results from a sum of carcinogenic factors, and key are extrinsic, such as smoking, alcohol, and chronic exposition to sunlight [3, 4, 6, 7, 12, 13, 15, 18, 19, 21-27]. However, other factors can contribute to the development of oral cancer, although the literature is not yet clear. Consequently, the unsatisfactory level of correct answers for factor/cofactors as: excessive consumption of spicy foods, prolonged use of drinks and hot food, use of poor-fitting dentures, low consumption of fruits and vegetables did not prove out the expectations of the researchers.

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Currently, there are records that poor oral hygiene, poorly fitting dentures, broken teeth or dental remains, over the years, are causes of hyperplastic lesions, and therefore, the constant and long action of these oral conditions can be a cofactor for development of oral cancer, by favoring the action of other carcinogens, particularly tobacco and alcohol [2, 6, 15, 18, 19, 22].

Other behaviors also have been linked to oral cancer. Current knowledge has emphasized the important role of diet in cancer etiology. Studies have shown that nutritional deficiencies and inadequate diets act as sources of free radicals, which would be responsible for alterations in DNA and can foster the development of oropharyngeal cancer. Fruits and vegetables probably can reduce the risk of cancer of the oral cavity [6, 2, 12, 13, 15, 22]. And the consumption of hot beverages or foods due to thermal injury to mucosal cells can increase oral cancer risk, even though few conclusive studies have been carried out [2, 3, 12, 22].

The low level of knowledge about oral cancer evidenced by volunteers in this study probably is related to the fact that most had never received information on the subject. To reverse this situation it is suggested to offer campaigns on the subject, in accessible language, because of the very high percentage of respondents expressed interest in receiving instructions on this and other themes related to health and pointed out the lecture as the preferred strategy for the information transfer.

Although there is no conclusive studies on the impact of primary prevention strategies [23], many researchers [1-8, 12, 13, 16, 19-22, 24-27] admit that it is necessary to increase public awareness about cancer and precancerous lesions, including knowledge about the risk factors.

Information campaigns in the media, according to Van Der Waal et al. [24], have little effect; however, the distribution of leaflets can be very useful. Among the participants of this present study, this assertion is corroborated, since many of those who had received information reported educational materials as a major source available in the basic health units.

The problem regarding to this strategy type is that the specific educative materials on the oral cancer are still few and those available generally are in a language not accessible to the understanding of the lay population [19, 20, 24, 27]. Ent Thus, there is a failure to produce this material type to be shown among the population, so it is necessary

that the professionals responsible for preparing the material to consider the population level with which they will work.

As evidenced by Herr et al. [7], it is important that professionals of health services act in different social spaces, spreading accessible technical and scientific knowledge, and demystifying the disease, because the more informed the population are, the greater is the possibility to enable the identification of risk factors and to seek the prevention and diagnosis.

It should be noted that, although the nonprobability sampling design used in this study might be considered a limitation, our understanding is that the sample size and the fact that these subjects coming from different geographical areas of the city are factors that minimize the possibility of a bias in the selection of subjects. Therefore, we believe that the results can be extrapolated to the entire school population of the public school system in the city where the research took place. We also understand that the reality identified in this youth group should be occurring in other contexts of Santa Catarina, as well as in other regions of the country.

Given this reality and the positive attitude of respondents as to obtain more knowledge on the subject, the research team has developed lectures with distribution brochures to and the students comprising the target population. Therefore, the research motivated the scholars regarding the acquisition of knowledge that promote attitudes for prevention of oral cancer.

Finally, we point out that these data can be used by city managers responsible for planning educational and preventive actions, strengthening the work already begun with the subjects researched and extending it to the entire population.

Conclusion Based on the obtained results, it can be concluded that the students of the Public school system in the city of Itajaí do not have adequate knowledge on oral cancer.

Acknowledgements The authors thank the Program of Research Fellowship, Article no. 171/FUMDES/ Government of the State of Santa Catarina.

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References 1. Almeida FCS, Silva DP, Amoroso MA, Brito e Dias R, Crivello Junior O, Araújo ME. Popularização do autoexame da boca: um exemplo de educação não formal – parte II. Ciênc Saúde Coletiva.

2011;16(supl.1):1589-98.

2. Brasil. Ministério da Saúde. Secretaria de Assistência à Saúde. Instituto Nacional de Câncer – INCA. Falando sobre câncer da boca. Rio de Janeiro: INCA; 2002.

3. Dib LL, Souza RS, Tortamano N. Avaliação do conhecimento sobre câncer bucal entre os alunos de Odontologia, em diferentes unidades da Universidade Paulista. Rev Inst Ciênc Saúde. 2005 Oct-Dec;23(4):287-95.

4. Elango KJ, Anandkrishnan N, Suresh A, Iver SK, Kuriakose MA. Mouth self-examination to improve oral cancer awareness and early detection in a highrisk population. Oral Onc. 2011;47(7):620-4.

5. França DCC, Pinto MMO, Monteiro AD, Silva AAS, Zina O, Lima GS et al. Programa de diagnóstico e prevenção de câncer de boca: uma estratégia simples e eficaz. ROBRAC. 2010;19(49):159-61.

6. Garrote LF, Herrero R, Reyes RM, Vaccarella S, Anta JL, Ferbeye L et al. Risk factors for cancer of the oral cavity and oro-pharynx in Cuba. Br J Cancer. 2001;85:46-54.

7. Herr GE, Kolankiewicz ACB, Berlezi EM, Gomes JS, Magnago TSBS, Rosanelli CP et al. Avaliação de conhecimentos acerca da doença oncológica e práticas de cuidado com a saúde. Rev Bras Cancerol. 2013;59(1):33-41.

8. Hertrampf K, Wenz HJ, Koller M, Grund S, Wiltfang J. Early detection of oral cancer: dentists’ opinions and practices before and after educational interventions in Northern-Germany. J Craniomaxillofac Surg. 2013;41(8):e201-7.

11. Jung M. Cancer control and the communication innovation in South Korea: implications for cancer disparities. Asian Pacific J Cancer Prev.

2013;14(6):3411-7.

12. Key TJ, Schatzkin A, Willett WC, Allen NE, Spencer EA, Travis RC. Diet, nutrition and the prevention of cancer. Public Health Nutr.

2004;7(1A):187-200.

13. Leite ACE, Guerra ENS, Melo NS. Fatores de risco relacionados com o desenvolvimento do câncer bucal: revisão. Rev Clín Pesq Odontol.

2005;1(3):31-6.

14. Melo AUC, Ramalho LMP, Ribeiro CF, Rosa MRD. Informação e comportamento preventivo de pacientes do Programa de Saúde da Família de Aracaju a respeito de câncer de boca. Pesqui Bras Odontopediatria Clín Integr. 2012;12(3):377-82.

15. Meurman JH. Infectious and dietary risk factors of oral cancer. Oral Oncol. 2010;46:411-3.

16. Parizi JLS, Castro SD, Ponga CMQ, Parizi AGS. Conhecimento de acadêmicos de odontologia, cirurgiões-dentistas e população em geral sobre câncer de boca. Rev Assoc Paul Cir Dent.

2011;65(1):66-70.

17. Rahman B, Hawas N, Rahman MN, Rabah AF, Kawa S. Assessing dental students’ knowledge of oral cancer in the United Arab Emirates. Int Dent J. 2013;63(2):80-4.

18. Rosenquist K. Risk factors in oral and oropharyngeal squamous cell carcinoma: a population-based case-control study in southern Sweden. Swed Dent J Suppl. 2005;179:1-66.

19. Souza LRB, Ferraz KD, Pereira NS, Martins MS. Conhecimento acerca do câncer de boca e atitudes frente à sua etiologia e prevenção em um grupo de horticultores de Teresina (PI). Rev Bras Cancerol. 2011;52(1):31-9.

9. Instituto Brasileiro de Geografia e Estatística.

Cidades@ [cited 2013 Nov 26]. Available from: URL:http:// www.cidades.ibge.gov.br/xtras/home. php.

20. Srikanth Reddy B, Doshi D, Padma Reddy M, Kulkarni S, Gaffar AAM, Reddy V. Oral cancer awareness and knowledge among dental patients in South India. J Craniomaxillofac Surg.

2012;40(6):521-4.

10. Instituto Brasileiro de Geografia e Estatística.

Pesquisa Nacional de Saúde do Escolar 2012. Rio de Janeiro: IBGE; 2013 [cited 2013 Nov 26]. Available from: URL:http://www.ibge.gov.br/home/estatistica/ populacao/pense/2012/pense_2012.pdf.

21. Tadbir AA, Ebrahimi H, Pourshahidi S, Zeraatkar M. Evaluation of levels of knowledge about etiology and symptoms of oral cancer in southern Iran. Asian Pacific J Cancer Prev.

2013;14(4):2217-20.

49 – RSBO. 2015 Jan-Mar;12(1):41-9 Comunello et al. – Assessment of knowledge about oral cancer: study with students of public education

22. Toporcov TN, Biazevic MGH, Rotundo LDB, Andrade FP, Carvalho MB, Brasileiro RS et al.

Alimentos de origem animal e câncer de boca e de orofaringe. Rev Panam Salud Publica.

2012;32(3):185-91.

23. Torres-Pereira C, Angelim-Dias A, Melo NS, Lemos Jr CA, Oliveira EMF. Abordagem do câncer da boca: uma estratégia para os níveis primário e secundário de atenção em saúde. Cad Saúde Pública. 2012;28(Supl.):s30-9.

24. Van der Waal I, De Bree R, Brakenhoff R, Coebergh J. W. Early diagnosis in primary oral cancer: is it possible? Med Oral Patol Oral Cir Bucal. 2011;16(3):e300-5.

25. Van der Waal I. Are we able to reduce the mortality and morbidity of oral cancer: some considerations. Med Oral Patol Oral Cir Bucal.

2013;18(1):e33-7.

26. Vidal KL, Tenório APS, Brito BHG, Oliveira TBT, Pessoa ID. Conhecimento de escolares do sertão pernambucano sobre o câncer de boca. Pesqui Bras Odontopediatria Clín Integr.

2009;9(3):283-8.

27. Zanetti F, Azevedo MLC, Perez DEC, Silva SRC. Conhecimento e fatores de risco do câncer de boca em um programa de prevenção para motoristas de caminhão. Odontol Clín-Cient.

2011;10(3):233-41.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):50-5

Original Research Article

Evaluating of oral and salivary conditions of two specific groups of workers Nicolae Carvalho de Paula1 Carolina Dea Bruzamolin1 Paulo H. Tomazinho1 Luciane Variani Pizzatto1 Wellington M. Zaitter1 Eduardo Pizzatto1 Corresponding author: Eduardo Pizzatto Rua Professor Pedro Viriato Parigot de Souza, n. 5.300 – Campo Comprido CEP 81280-330 – Curitiba – PR – Brasil E-mail: epizzatto1@gmail.com 1

School of Dentistry, Positivo University – Curitiba – PR – Brazil.

Keywords: oral health; occupational dentistry; DMF index; saliva.

Abstract Introduction and Objective: Tooth decay is one of the most common chronic oral diseases found in industrial countries and is a multifactorial disease which has sugar as a key dietary factor. The amount of saliva concentration and presence of cariogenic bacteria will favor the development of caries. Because of this, the aim of this study was to collect and analyze data on oral alterations referred to tooth decay, oral pH changes, and changes of the oral microbiota in two distinct groups of workers. Material and methods: 30 individuals belonging to two different groups of workers: group A (GA) – workers who maintain daily contact with the confectionery; group B (GB) – workers who do not have such contact. Saliva collection was done by analysis of the salivary pH in both groups, as well as cultivation of Lactobacillus spp and S. mutans. We also evaluate the dental status of individuals belonging to the two groups through the DMFT index. Results: After the examinations of 30 workers (17 from the GA [9 men and 8 women] and 13 in the GB [7 men and 6 women]), the mean DMFT of the individuals in the group A and group B, was 7.41 (SD 5.14) 7.08 (SD 5.56), respectively, without statistically significant differences (p < 0.05). The count of S. mutans and Lactobacillus spp, was not statistically significant.

Conclusion: There was no statistically significant relationship between presence of dental caries and the fact that workers are in contact with sugar because they work on candy food industry, but new studies are needed for more precise research.

51 – RSBO. 2015 Jan-Mar;12(1):50-5 Paula et al. – Evaluating of oral and salivary conditions of two specific groups of workers

Introduction

Material and methods

Tooth decay is one of the chronic oral diseases more common found in industrial countries. Despite the reduction in the severity and prevalence of the disease, caries still has gradually increased with age and remains a problem of public health [15].

Dental caries is a multifactorial disease and occurs due to the diet, negligent oral hygiene, biofilm maturation time, and the presence of acids and bacteria in the oral cavity [6, 10].

The dietary factor known as major cause of tooth decay is sugar. This is associated with the presence of acids in the mouth by the action of bacteria, causing a process of dissolution and mineral loss of dental enamel [10, 11].

In the study of Sigh et al. [16] there was a correlation between exposure to sugar with caries incidence in workers with and without dental health insurance in India. The oral health was assessed and a survey on social-demographic factors, including: exposure to sugar, smoking, and oral hygiene habits.

It was found that workers who had frequency of exposure to sugar of three or more times a week were shown to have a higher caries incidence than workers who had no exposure.

Saliva has a fundamental role in the oral cavity maintenance, because acts as a buffer solution to neutralize the acids from attack of bacteria produced during sucrose fermentation, so that the oral environment becomes neutral. Thus, the adhesion of bacteria on tooth surface and a possible loss of minerals, calcium and phosphate are avoided [6, 10, 17].

Streptococcus mutans, the main bacterium that causes dental caries, is an extracellular and acidogenic bacterium inducing dental caries in humans with a high-sucrose diet. The presence of S. mutans in the oral cavity, associated to poor hygiene and high consumption of carbohydrates, favors acidogenesis, triggering the carious lesions initially in dental enamel [10, 12, 18]. For a better determination of the patient's risk to develop caries, some tests have been performed: salivary test (to check flow and salivary pH) and bacterial count (which is done by counting bacterial colonies forming units) [6, 17].

This research is justified because there is no evidence of dental caries and salivary change caused by the work environment in the confectionery industry workers. The aim of this study was to collect and analyze data on oral alterations referred to caries, oral pH changes, and changes in the oral microbiota in two groups: candy industry and real estate workers.

Previously, this study was evaluated and submitted to the Ethics Committee in Research of Positivo University, according to Resolution n. #196/96. A total of 30 workers of two distinct groups were evaluated: Group A (GA) – workers who maintain daily contact with sweet production; and Group B (GB) – workers who do not have such contact. The age group of the subjects in both groups was matched in 18-45 years with working time over six months on the activity and did not use orthodontic appliances.

Caries assessment The clinical intraoral examination performed in the sample group followed the model recommended by the World Health Organization (WHO). The following variables were evaluated: age, sex, length of stay in employment and dental caries (this through the DMFT index) [11].

That exam was performed with the aid of n. 5 flat mirror, WHO periodontal probe, and wooden spatula. These objects made up kits that were opened only at the time of the examination, passing through a washing process and autoclaving at the end of the day. The data were recorded in individual medical records. These tests were performed in-house, by a single calibrated examiner under natural light, with the person sitting and the examiner standing. It is noteworthy that the diagnosis, during the intraoral examination of pathological conditions, especially triggering of nociceptive processes, received referral to clinical treatment.

It is worth noting that prior contact was conducted explaining the objectives of this study and protocol of the examinations sent to person in charge of each company in order to obtain necessary authorization to perform this research. Moreover, all workers signed a free and clarified consent form to undergo intraoral examination.

The data collected during the diagnosis phase were entered into the statistical program Epibuco produced in Fox Base language, which were tabulated and received statistical treatment. For comparison between groups we used analysis of variance – ANOVA.

Salivary collection Two to three hours after last oral hygiene, a sterile cotton roll has been chewed for 1 minute and the saliva produced was swallowed. The saliva produced thereafter was collected by sputum for 3 minutes in sterile plastic vial. The vials containing

52 – RSBO. 2015 Jan-Mar;12(1):50-5 Paula et al. – Evaluating of oral and salivary conditions of two specific groups of workers

the saliva were stored in Styrofoam box with crushed ice and transported to the Microbiologic Laboratory of Positivo University.

Determination of salivary pH With the saliva samples in the Microbiology Laboratory of Positivo University, a 1 ml aliquot was removed from each sample and packaged under 1.8 ml sterile disposable plastic Eppendorff tubes for further saliva analysis. After this procedure, the saliva remaining in each collection flask had the pH determined by pH meter, previously calibrated with pH buffers from 4 to 7.

Figure 2 – Kits for culture in rogosa agar

Lactobacillus spp and S. mutans cultivation For S. mutans cultivation, 0.5 ml aliquots of saliva from each individual were homogenized and serial diluted in 4.5 ml of saline solution, 0.85% by 1:10000 dilution. After dilution, 0.1 ml aliquots of each dilution were plated on Agar Mitis Salivarius culture media supplemented with 20% sucrose. The plates were incubated in a bacteriological incubator (FANEM, Sao Paulo, Brazil) at 37°C for 48 hours, after which the colonies grown were counted under a stereoscopic microscope to determine the unit forming colony per ml of saliva (CFU/ml) (figure 1).

After the growth period on the medium surface was compared with template supplied by the manufacturer to determine the amount of CFU/ml in saliva (figure 3).

Figure 3 – Determination of CFU/ml in saliva

Statistics The means of the groups were statistically analyzed by Epibuco software, at significance level of 5%. The Student t test was used to verify the statistical differences between the groups.

Figure 1 – S. mutans cultivation and culture

For cultivation three kits with Rogosa agar (DENTALLABOR, Pinhais, Brazil). For that, the remaining of saliva sample was pipetted with disposable Pasteur pipette and saliva aliquots were spread on the lateral side of the pipette itself on the agar. The tubes containing the culture were also incubated at 37ºC for 48 hours (figure 2).

Results Thirty workers were examined: 17 of GA (9 men and 8 women) and 13 of GB (7 men and 6 women).

The mean DMFT of the individuals of GA was 7.41 (SD 5.14) and GB was 7.08 (SD 5.56). However, this difference was not statistically significant (p<0.05) (tables I and II).

53 – RSBO. 2015 Jan-Mar;12(1):50-5 Paula et al. – Evaluating of oral and salivary conditions of two specific groups of workers

Table I – DMFT and participants according to group

Group

H

C

O/C

O

P

DMTF

N

A

21.00

2.41

0.29

3.47

1.24

7.41

17

B

21.15

0.92

0.23

4.62

1.31

7.08

13

Table II – Mean, standard deviation (SD), 95% confidence interval, median, minimum, maximum and value numbers for DMTF

Group

Mean

SD

CI (li)

CI (Is)

Median

A

7.41

5.14

4.77

10.05

7.0

Min. 0

Max.

No.

16

17

B 7.08 5.56 3.72 10.44 6.0 0 17 13

The mean salivary pH was 7.99 for group A and 7.67 for group B, without statistically significant difference (p<0.05).

S. mutans count was not significantly different between the two groups (p <0.05), and the GA mean was 65.84x106 (CFU/ml), whereas GB mean was 68.72x106 (CFU/ml).

The mean count of Lactobacillus spp 105 (CFU/ml) both for GA and GB (p < 0.05).

Discussion At the working environment, there is exposure to various diverse factors that may cause damage to human health. Because of this, depending on the nature of the damage suffered by the worker, severe damage to oral health might occur [19].

The Dentistry at Work covers the worker’s health as a priority and seeks to find possible factors that may cause disease. However, there are few current studies in the literature that address the Dentistry at Work and worker risk. Therefore, current studies should be conducted and Dentistry must have a deeper look in relation to oral health of worker.

The methods and materials used in the study were very efficient, since, in the obtaining results, there was only time problem between the saliva collection and analysis of the obtained material.

The inf luence of saliva buffer capacity was an important factor to indicate the restoration of oral pH to both GA (mean pH 7.99) and G B (mean pH 7.67), which demonstrates that the result of oral pH values changed [18].

There was no statistical difference in the results obtained in S. mutans and Lactobacillus spp count.

It is said in some studies that the count may have certain limitations, because other predisposing factors must be taken into consideration for the development of caries, such as biofilm maturation, time, poor hygiene and cariogenic diet [6].

A st udy conducted i n 1978 veri f ied t he prevalence of dental caries in workers of candy

factories in Israel and compared with workers of textile industries. Values found in workers of candy industries were significantly higher than those of the other group, suggesting the need for special attention to workers exposed to air sugar [1].

A survey carried out the assessment in the confectionery industry workers, separated into groups: Chocolate, sweet biscuits, bakery, and sweets. Through clinical oral examination, it was found that workers of chocolates and cookies had higher caries, with a higher incidence in those who are in employment for longer and in confectioners who are exposed to sugar 4-6 hours a day. Some workers, in addition to caries, already had periodontal disease and needed treatment and more efficient control of oral diseases [14].

The statistical equality in DMFT index of the two groups is also due to the average of decayed teeth to be 2.41 in the GA and 0.92 in B and the average of restored teeth in GA to be 3.47 and in GB 4.62. These means directly altered DMFT result of the two groups, which demonstrated greater activity of caries in GA, which is exposed to sugar, and greater amount of restorations in Group B. It is assumed that workers of chocolates industries, chewing gum, and sugar are daily exposed to fine particles of raw materials suspended in t he a ir, such as f lour, refined suga r a nd sweeteners. A study was carried out to assess the incidence of caries in a group of exposed and unexposed workers, but it was not observed relation in DMFT increase resulting from exposure to sugars [20].

54 – RSBO. 2015 Jan-Mar;12(1):50-5 Paula et al. – Evaluating of oral and salivary conditions of two specific groups of workers

By evaluating the oral health status of workers in a confectionery industry in Denmark, Petersen [13] concluded that these form a risk group for dental caries, being necessary to establish a preventive oral health program as part of the occupational health program of the company. A study on Chinese airline pilots showed that pilots consumed sugar more frequently and had higher caries index than those that did not consumed. But there was no significance difference between exposure to sugar and caries, because pilots often underwent dental visits [12].

Masalin et al. [7] evaluated the oral health conditions of 298 workers in candy factories of Finland, concurrently assessed the concentrations of sugar and flour in the workplace, which were within the accepted limits. The researchers concluded that the consumption of sugary products, the frequency of use, and the behavior of workers in relation to oral health are the main responsible factors for the high rates of dental problems in these workers.

Masalin et al. [8] analyzes the state of dental caries, food behavior, and oral health. In salivary microbiological discoveries of 338 confectionery workers, caries experience was found in high quantities. Food habits were the most important factors affecting the occurrence of caries and its susceptibility. The authors concluded that the confectionery industry did not seem to be an extremely dangerous environment for oral health in general.

Conclusion Based on the results, it can be concluded that

• In the specific groups of workers statistically significant difference was not proven between the studied variables; • Due to t he lack of current literature, further studies should be conducted to analyze the correlation of oral diseases and exposure to occupational hazards by workers; • It is suggested further studies following the proposed methodology, using a more significant sample group in order to verify that the results obtained here are reproducible.

2. Carvalho VA, Espindula MG, Valentino TA, Turssi CP. Approaches used in the assessment of caries risk. RFO. 2011 Jan-Apr;16(1):105-9.

3. Chen X, Liu Y, Yu Q, Zheng L, Hong X, Yan F et al. Dental caries status and oral health behavior among civilian pilots. Aviat Space Environ Med. 2014 Oct;85(10):999-1004.

4. Hics J, Garcia-Godoy F, Flaitz C. Biological factors in dental caries: role of saliva and dental plaque in a dynamic process of demineralization and remineralization. J Clin Pediatr Dent.

2003;28:47-52.

5. Kalesinskas P, Kacergius T, Ambrozaitis A, Peciuliene˙ V, Ericson D. Reducing dental plaque formation and caries development. A review of current methods and implications for novel pharmaceuticals. Stomatologija, Baltic Dental and Maxillofacial Journal. 2014;16(2):44-52.

6. Kidd EAM, Fejerskov O. What constitutes dental caries? Histopathology of carious enamel and dentin related to the action of cariogenic biofilms.

J Dent Res. 2004;35-8.

7. Masalin K, Murtomaa H, Meurman JH. Oral health of workers in the modern finnish confectionery industry. Community Dent Oral Epidemiol. 1990;3(18):126-30.

8. Masalin KE, Murtomaa HT, Sipila KP. Dental caries risk in relation to dietary habits and dental services in two industrial populations. Journal Public Health Dent. 1994;3(54):160-6.

9. Midorikawa ET. Definição do campo de atuação e funções do cirurgião-dentista na equipe da saúde do trabalhador. Revista CIPA. 2001 May;(258):52-69.

10. Moynihan P. The interrelationship between diet and oral health. Proc Nutr Soc. 2005;64:571-80.

11. Organização Mundial de Saúde. Levantamento epidemiológico básico em saúde bucal: manual de instruções. 4. ed. Genebra: OMS; 1999.

12. Pereira AG, Neves AM, Trindade AC. Imunologia da cárie dentária. Acta Med Port. 2010;23:663-8.

References

13. Petersen PE. Evaluation of a dental preventive program for Danish chocolate workers. Community Dent Oral Epidemiol. 1989(17):53-9.

1. Anaise JZ. Prevalence of dental caries among workers in the sweetes industry in Israel. Community Dent Oral Epidemiol. 1978;6(6):286-9.

14. Rekha R, Hiremath SS. Oral health status and treatment requirments of confectionery.

2002;13(3-4):161-5.

55 – RSBO. 2015 Jan-Mar;12(1):50-5 Paula et al. – Evaluating of oral and salivary conditions of two specific groups of workers

15. Sheiham A, James WP. A reapraisal of the quantitative relationship between sugar intake and dental caries: the need for new criteria for developing goals for sugar intake. BMC Public Health. 2014 Sep 16;14(1):1-8.

16. Singh A, Purohit BM, Masih N, Kahndelwal PK. Risk factors for oral diseases among workers with and without dental insurance in a national social security scheme in India. Int Dent J. 2014;64(2):89-95.

1 7 . S t r u z˙y c k a I . T h e o r a l m i c r o b i o m e i n dental caries polish. Journal of Microbiology.

2014;63(2):127-35.

18. Takahashi N, Nyvad B. The role of bacteria in the caries process: ecological perspectives. J Dent Res. 2011 Mar;90(3):294-303.

19. Tannous RA, Silva UA. Revisão de literatura – Odontologia do trabalho: aplicabilidade e importância na saúde bucal do trabalhador. UFES Rev Odontol. 2007 Sep-Dec;9(3):43-8.

20. Tomita NE, Cordeiro R, Mendonça J, Senger V, Lopes ES. Saúde bucal dos trabalhadores de uma indústria alimentícia de centro-oeste paulista. Rev FOB. 1999;7(1/2):67-71.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):56-60

Original Research Article

Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials Kiany Scarssi Nunes1 Luiza Bonezi Boff1 Juliana Royer1 Tiago André Fontoura de Melo1 Corresponding author: Tiago André Fontoura de Melo Rua Nicola Mathias Falci, n. 151 / casa 16 – Jardim do Salso CEP 91410-330 – Porto Alegre – RS – Brazil E-mail: tafmelo@gmail.com 1

Dental School, College of Serra Gaúcha – Caxias do Sul – RS – Brazil.

Received for publication: November 19, 2014. Accepted for publication: December 22, 2014.

Keywords: Endodontics; root canal filling materials; solubility.

Abstract Introduction and Objective: This study aimed to analyze the level of radiopacity of different materials used in endodontic retrofilling procedure regarding the influence of humidity on solubilization over a period of 30 days. Material and methods: 10 specimens with 10 mm diameter and 1mm thick were made with each of the materials.

The following retrograde filling materials were tested: glass ionomer Vitro Fil LC®, IRM®, MTA Angelus®, Sealer 26® and silver amalgam capsule DFL Alloy. These materials have been handled by a single operator, according to the recommendations of their respective manufacturers. The obtained specimens were surrounded by moist gauze and incubated in a heater for thirty days at 37°C and 100% humidity. The samples were x-rayed, via the digital system Digora Optime®, at three different moments: first, 15th, and 30th day of incubation. For the analysis of radiopacity of the samples, the shades of gray were measured through ImageTool® software. Results and Conclusion: Data were subjected to statistical analysis using ANOVA, repeated measures design, followed by Tukey test with a significance level of 5%. According to the results, it could be observed that the only tested materials that have undergone changes in radiopacity, in accordance with the period of incubation in humidity, were the glass ionomer Vitro Fil LC® and Sealer 26®.

57 – RSBO. 2015 Jan-Mar;12(1):56-60 Nunes et al. – Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

Introduction The retrograde filling is a procedure often used in paraendodontic surgery in order to seal the canal with at root resection in the apical portion of the tooth root [19, 22]. To verify the correct filling of retrocavity and to facilitate surgery following-up, the retrofilling material must provide radiopacity enough to be distinguished from the surrounding anatomical structures [18]. According to Shah et al. [16], the materials used in retrofilling must show a certain level of radiopacity that enables differentiating the root dentin from support bone.

Many materials have been tested and used in paraendodontic surgery, such as silver amalgam [10], MTA [5], glass ionomer [13] and zinc oxide and eugenol-based cements [7]. But to date none behaved optimally.

The ideal retrofilling material should be easy to handle, have good radiopacity, provide dimensional stability in order to maintain a good apical sealing, be non-toxic to periapical tissues, and be insoluble or have low solubility [11].

Thus, given that the used root-end filling materials are in close and continuous contact with the tissue fluids of the periapical region, this study aimed to analyze the influence of humidity on the level of radiopacity of some dental materials used in endodontic retrofilling.

Material and methods The root-end filling materials tested were divided into five groups: group I – glass ionomer Vitro Fil LC® (DFL Produtos Odontológicos, Rio de Janeiro, Brazil), group II – IRM® (Dentsply/Maillefer Inst ruments S. A., Ba lla ig ues, Sw it zerla nd), group III – MTA Angelus® (Angelus Indústria de Produtos Odontológicos Ltda., Londrina, Paraná, Brazil), group IV – Sealer 26® (Dentsply/Maillefer Instruments S.A., Ballaigues, Switzerland), and

group V – silver amalgam capsules DFL Alloy (DFL Produtos Odontológicos, Rio de Janeiro, Brazil).

Ten specimens with 10 mm diameter and 1 mm thick were prepared with aid of a flexible silicone condensation matrix (Vigodent S.A. Indústria e Comércio, Bonsucesso, Rio de Janeiro, Brazil), for each of the materials. The root-end filling materials were handled by a single operator and according to the recommendations of the respective manufacturers.

The samples during the experiment, were wrapped in moist gauze and incubated for 30 days, at 37ºC and 100% humidity, in a bacteriological incubator403/ N (Multitec Equipamentos para L a b orat ór io, C a no a s, R io Gra nde do Su l, Brazil).

To carry out the radiographic images, the samples were placed on an image plate (sensor) digital system Digora Optime® (Soredex Corp., Tuusula, Finland). This sensitized plate, after t he radiographic shot w it h x-ray machine X Gnatus (70kVp – 7mA, Gnatus Equipamentos Odontológicos Ltda., Ribeirão Preto, São Paulo, Brazil), was introduced in laser optical reader of Digora Optime® system in order to obtain the desired image with an exposure time of 0,32 seconds at a distance of 30 cm. For standardization of distance and position of images a customized to a radiographic platform previously was made.

The radiographic images of the specimens were made at three different times: 1st, 15th, and 30th day after incubation in the heater. In total, 150 radiographic images were made.

To analyze the radiopacity the grayscale of the images were measured through the ImageTool® software (UTHSCSA, San Antonio, Texas). To measure the shades of gray, ranging from 0 to 255 pixels, the “histogram” was used in a standard area of 20 x 19 pixels positioned in a standardized manner at the central area of the images (figure 1).

58 – RSBO. 2015 Jan-Mar;12(1):56-60 Nunes et al. – Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

Figure 1 – Radiopacity measurement of the cements through the ImageTool® software

The data obtained in the assessment were treated and analyzed by ANOVA statistical analysis, using the repeated measure design, following by Tukey test for multiple comparisons, at a significance level of 5%.

Results The results with the mean and standard deviation of radiopacity in pixels of the five root-end filling materials are shown in table I. Table I – Comparative table of the mean and standard deviation of the radiopacity of root-end filling materials in relation to the time of analysis

Analysis time (day) Experimental group Group I – Ionomer Group II – IRM® Group III – MTA Angelus® Group IV – Sealer 26® Group V – Amalgam

1

15th

st

30th

Mean

SD

Mean

SD

Mean

SD

96.80A 155.10A 134.70A 148.50A 255.00A

2.22 2.03 5.57 3.07 0.00

95.30B 154.50A 133.10A 143.60B 255.00A

2.33 2.20 5.17 3.82 0.00

95.00B 154.50A 132.50A 136.60C 255.00A

2.40 2.33 5.02 4.54 0.00

Means followed by different capital letters in line differ significantly by ANOVA using repeated measure design, followed by the Multiple Comparison Tukey Test, at a significance level of 5%

59 – RSBO. 2015 Jan-Mar;12(1):56-60 Nunes et al. – Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

Discussion The sea rch for t he idea l biomateria l for paraendodontic surgery is a constant in modern Endodontics, since it is difficult to obtain in a single product all the desired physical-chemical, mechanical and biological.

The difference in radiopacity between the different retrofilling materials employed in the paraendodontic surgery exposes some deficiency in the existing products on dental market, which can serve as exclusion criteria in clinical choice for the material to be used with this purpose.

Thus, the radiopacity has received attention in several studies [4, 18, 24]. Some studies [1, 2] have used photodensitometry and aluminum scales to compare the radiopacity of sealers. However, in recent years, evaluations from digital radiographic images comparing or not to the aluminum scales have been quite frequent ly [3, 23]. Wit h t he advent of digital images, this type of assessment has become more effective and fast, since the radiographic density is directly obtained, because the pixels already have their certain shades of gray.

Based on the assessment of the gray tones, it could be appreciated in this study statistical difference in the radiopacity only for following the root-end filling materials: glass ionomer Vitro Fil LC® and Sealer 26®.

The solubilization and disintegration of the materials allow the appearance of voids within the obturator mass, promoting retrograde infiltration of tissue fluids, which may compromise the sealing and the treatment success.

In the studies of Fidel et al. [9], Tanomaru Filho et al. [20], Scelza et al. [15], and Kuga et al. [14], Sealer 26® showed low solubility index, corroborating the results obtained in this present study. Sealer 26® is an epoxy resin-based cement containing calcium hydroxide in its composition.

By having its sealing ability compared with the use of IRM® and glass ionomer cement, with the specimens filled with these materials in contact with human saliva for 60 days, it was observed that Sealer 26® showed excellent ability to seal when used as retrograde filling material, as well as great capacity to prevent bacterial leakage [17].

With regard to glass ionomer, Carvalho Júnior et al. [6] studied the solubility, disintegration and dimensional changes of Ketac-ENDO® compared to Endofill® and Sealer 26®. They verified that Endofill® and Ketac-ENDO® had higher solubility values and disintegration than those recommended by the ADA specification. According to Gorodovsky and Zidan [12], the glass ionomer presented as

inherent characteristics: solubility and power of disintegration in liquids and wet media.

Concerning to the silver amalgam capsules DFL Alloy, IRM®, and MTA Angelus® did not show radiopacity alterations at the analyzed periods.

A lt hough t he silver a ma lga m has presented satisfactory results for radiopacity, it has some limitations, such co mo high power of oxidation and tissue contamination by mercury [11]. According to the study of Crooks et al. [8], zinc oxideeugenol-based materials, such as IRM®, have good mechanical resistance and low solubility.

Notwithstanding, according to Torabinejad et al.

[21], MTA, in addition to biocompatibility, favors the formation of hard tissue after paraendodontic surgery, and does not exhibit, after setting, solubility in the presence of humidity, and thus is the best material for use in retrograde fillings.

Conclusion According to the results found, it could be seen that the glass ionomer Vitro Fil LC® and Sealer 26® underwent radiopacity alterations, according to the period of humidity incubation. Concerning to IRM®, MTA Angelus® and silver amalgam DFL Alloy did not undergo modifications.

References 1. Almeida PM, Antonio MPS, Moura AAM. Estudo comparativo da radiopacidade de quatro cimentos obturadores de canais radiculares. Rev Inst Ciênc Saúde. 1998;16(1):27-30.

2. Beyer-Olsen EM, Orstavik D. Radiopacity of root canal sealers. Oral Surg Oral Med Oral Pathol.

1981;51(3):320-8.

3. Bicheri SAV, Victorino FR. Comparative evaluation of radiopacity of MTA Fillapex ® endodontic sealer through a digital radiograph system. RSBO. 2013;10(2):149-52.

4. Bortoluzzi EA, Guerreiro-Tanomaru JM, Tanomaru-Filho M, Duarte MA. Radiographic effect of different radiopacifiers on a potential retrograde filling material. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;108(4):628-32.

5. Camilleri J, Sorrentino F, Damidot D. Investigation of the hydration and bioactivity of radiopacified tricalcium silicate cement, Biodentine and MTA Angelus. Dent Mater. 2013;29(5):58093.

60 – RSBO. 2015 Jan-Mar;12(1):56-60 Nunes et al. – Radiopacity analysis of humidity influence on the solubilization of different retrograde filling materials

6. Carvalho Júnior JR, Guimarães LF, CorrerSobrinho L, Pécora JD, Sousa-Neto MD. Evaluation of solubility, disintegration, and dimensional alterations of a glass ionomer root canal sealer.

Braz Dent J. 2003;14(2):114-8.

7. Chong BS, Pitt Ford TR, Hudson MB. A prospective clinical study of mineral trioxide aggregate and IRM when used as root-end filling materials in endodontic surgery. Int Endod J. 2003;36(8):520-6.

8. Crooks WG, Anderson RW, Powell BJ, Kimbrough WF. Longitudinal evaluation of the seal of IRM root end fillings. J Endod. 1994;20(5):250-2.

9. Fidel RAS, Spanó JCE, Barbin EL, Silva RG, Pécora JD. Estudo in vitro sobre a solubilidade e a desintegração de alguns cimentos endodônticos que contêm hidróxido de cálcio. Rev Odontol Univ São Paulo. 1994;8(3):217-20.

10. Frank AL, Glick DH, Patterson SS, Weine FS. Long-term evaluation of surgically placed amalgam fillings. J Endod. 1992;18(8):391-8.

11. Gartner AH, Dorn SO. Advances in endodontic surgery. Dent Clin North Am. 1992;36(2):35778.

12. Gorodovsky S, Zidan O. Retentive strength, disintegration, and marginal quality of luting cements. J Prosthet Dent. 1992;68(2):269-74.

16. Shah PM, Chong BS, Sidhu SK, Ford TR. Radiopacity of potential root-end filling materials.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod.

1996;81(4):476-9.

17. Siqueira Júnior JF, Rôças IN, Abad EC, Castro AJ, Gahyva SM, Favieri A. Ability of three root-end filling materials to prevent bacterial leakage. J Endod. 2001;27(11):673-5.

18. Tagger M, Katz A. A standard for radiopacity of root-end (retrograde) filling materials is urgently needed. Int Endod J. 2004;37(4):260-4.

19. Tanomaru Filho M, Luis MR, Leonardo MR, Tanomaru JM, Silva LA. Evaluation of periapical repair following retrograde filling with different root-end filling materials in dog teeth with periapical lesions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;102(1):127-32.

20. Tanomaru Filho M, Moraes IG, Duarte MAH, Arekaki OT, Nishiyama CK. Avaliação do selamento apical de dois cimentos endodônticos à base de hidróxido de cálcio. Rev Bras Odont. 1996;53(3): 2-4.

21. Torabinejad M, Hong CU, McDonald F, Pitt Ford TR. Physical and chemical properties of a new root-end filling material. J Endod. 1995;21(7): 349-53.

13. Jesslén P, Zetterqvist L, Heimdahl A. Longterm results of amalgam versus glass ionomer cement as apical sealant after apicectomy. Oral Surg Oral Med Oral Pathol Oral Radiol Endod.

1995;79(1):101-3.

22. Torabinejad M, Pitt Ford TR, McKendry DJ, Abedi HR, Miller DA, Kariyawasam SP. Histologic assessment of mineral trioxide aggregate as a root-end filling in monkeys. J Endod. 1997;23(4): 225-8.

14. Kuga MC, Campos EA, Sant’Anna Júnior A, Vasconcelos FL, Silva AN, Nascimento CA. Avaliação do pH, da solubilidade e da infiltração marginal em retrobturações com o Sealer 26® puro ou acrescido de iodofórmio. RSBO. 2010;7(4):389-95.

23. Vidotto APM, Cunha RS, Zeferino EG, Rocha DGP, Martin AS, Bueno CES. Comparison of MTA Fillapex radiopacity with five root canal sealers.

RSBO. 2011;8(4):404-9.

15. Scelza MFZ, Scelza P, Costa RF, Câmara A. Estudo comparativo das propriedades de escoamento, solubilização e desintegração de alguns cimentos endodônticos. Pesq Bras Odontoped Clín Integr. 2006;6(3):243-7.

24. Vivan RR, Ordinola-Zapata R, Bramante CM, Bernardineli N, Garcia RB, Hungaro Duarte MA et al. Evaluation of the radiopacity of some commercial and experimental root-end filling materials. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2009;108(6):35-8.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):61-7

Original Research Article

Linear setting expansion of different gypsum products César Antunes de Freitas1 Tatiana Sanches Zanotti2 Fabio Antonio Piola Rizzante1 Adilson Yoshio Furuse1 Márcia Furtado Antunes de Freitas3 Corresponding author: Adilson Yoshio Furuse Al. Dr. Octávio Pinheiro Brisolla, 9-75 – Bauru CEP 17012-901 – Bauru – SP – Brasil E-mail: furuse@usp.br Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo – Bauru – SP – Brazil.

2 Private practice – São Carlos – SP – Brazil.

3 Department of Dentistry, Regional Integrated University of High Uruguay and Missions – Erechim – RS – Brazil.

1

Received for publication: December 1, 2014. Accepted for publication: December 22, 2014.

Keywords: calcium sulfate; models, anatomic; dental impression materials.

Abstract Introduction: Stone casts are used in dentistry to allow the confection of indirect restorations. Thus, gypsum dimensional stability is fundamental in order to achieve a precise fit between dental structure and restorative material. Objective: The purpose of the present study was to evaluate the hygroscopic linear expansion of commercially available gypsum products. Material and methods: Fifteen dental stones were analyzed (4 type II, 5 type III, 4 type IV and 2 type V), with n = 5. One hundred grams of each gypsum product were mixed following the respective manufacturers’ recommendations for powder/water ratio and poured into a V-shape mold, connected to an expansion-measuring device. The hygroscopic expansion was evaluated during 120 min and the collected data was converted into percentage and compared to initial dimensions of the specimen. Results: All type II and V dental stones showed expansion values compatible to the ADA and ISO recommendations. Considering type III stones, only Rutenium 3 was compatible with the recommendations. For type IV, only Durone IV showed expansion values higher than that recommended by ADA, but lower than that of ISO recommendations.

Conclusion: The hygroscopic linear expansion of gypsum products should be periodically controlled in order to ensure their precision and reliability to dental practice.

62 – RSBO. 2015 Jan-Mar;12(1):61-7 Freitas et al. – Linear setting expansion of different gypsum products

Introduction In dentistry, in traditional indirect restoration methods, derivatives of gypsum are used, also known as calcium sulfate dihydrate. The manufacturer calcines the dihydrate, transforming it into calcium sulfate hemihydrate which is gypsum itself. After mixing the water with gypsum powder the inverse reaction occurs, so that the gypsum returns to the state of gypsite, after the centered crystal needles growth, forming the spherulites. This growth results in the so called linear setting expansion, as pointed out by several authors [6, 7, 12].

In the Specification n. 25 (since 1972) of the American Dental Association (ADA) [1], and in the similar Specification of the International Organization for Standardization (ISO) [5], dental gypsum can be classified into five types, each one will determine their application: I – Impression plaster; II – Dental plaster; III – Dental stone; IV – Dental stone (high strength); V – Dental stone (high strength, high expansion).

Among many dental applications, gypsum is used for making casts on which various types of prosthetic pieces can be constructed. In the specification of each one of the aforementioned associations, for each type of gypsum is clearly established a range of values allowed for the linear setting expansion, expressed as a percentage, as is briefly illustrated in table I. Table I – Value range (expressed in %) allowed by ADA and ISO, for the linear setting expansion of the different dental plasters

Type ADA ISO I (impression) 0.0 to 0.15 0.0 to 0.15 II (dental plaster) 0.0 to 0.30 0.0 to 0.30 III (dental stone) 0.0 to 0.20 0.0 to 0.20 IV (dental stone; high strength) 0.0 to 0.10 0.0 to 0.15 V (dental stone; high strength, high expansion) 0.10 to 0.30 0.16 to 0.30 Inadequate properties of a plaster can harm the performance of the model with which it is made, and may affect the final quality of the restorative process. Thus, there is great concern about the procedures required to obtain the corresponding plaster model [10].

The accuracy of a plaster model depends on a number of factors, such as impression technique, the molding material used therein, the type of gypsum used to obtain the model and its storage form [11]. Thus, it is important the study not only of the impression accuracy, but also the quality of dental casts available to fit the models [2].

It is therefore justified the need for studying the large number (of different types) of plaster on the market so that there is always a quality control, ensuring minor mistakes during the planning and the preparation of prosthetic pieces. The aim of this study was to evaluate the normal setting expansion of existing plaster in local market (between which there is no type I), to verify whether the information from the manufacturers correspond to the real value and also if there is compliance with the relevant Specifications from both ADA and ISO.

Material and methods All experimental phase of this study was conducted in environmental temperature between 20 to 25ºC and relative air humidity of 50 (±10)%, as required by ADA [1] and ISO [5].

Both Specifications demand the use of a device so-called extensometer, composed of a base supporting a channel made of not informed materials (in this case stainless steel was used), but whose two inclined walls should form an angle of 90 degrees between them; each wall should display internal width of 30±1 mm and length of 25±1 mm. Each channel should be covered by polytetrafluoroethylene (PTFE) sheet, with thickness ranging from 0.1 to 0.2 mm; the channel should still be closed in one of the sides by a fixed piece; the free ending is fixed onto a mobile block (stainless steel with 200±10 g of mass). The distance of the fixed piece from the mobile block should be 100±0.1 mm, which is so called measuring length. A micrometer should be used (also known as display clock, or micrometer clock, or dial gauge), whose action load cannot be greater than 0.8 N, also fixed onto the base. Proper isolating agent (such as Vaseline) should also be applied internally on the channel and mobile block (parts in touch with the plaster to be analyzed).

The freshly mixed plaster/water mass should be poured inside the channel, so that the surface is leveled, which must be then covered by the PTFE sheet, basically keeping the aforementioned length.

Immediately, the micrometer should have its tip touching the mobile block, moment in which the ring should be turned until the pointer is adjusted on zero; this will be considered as the

63 – RSBO. 2015 Jan-Mar;12(1):61-7 Freitas et al. – Linear setting expansion of different gypsum products

initial reading and should always be taken at 60 s after the plaster insertion in the channel; the final measurement should be taken at 120±1 min, counting from the beginning of the mixture of the original components. The setting expansion should be calculated as the percentage of the original

length, by about the second decimal point, for a minimum of two valid tests.

Five tests were performed for each one of the plasters of table II, which displays the manufacturers, batches, water/powder ratio indicated by the manufacturer and the water/powder ratio used.

Table II – Information on the plaster, respective manufacturers, batches, recommended water/powder ratio (W/P), and used W/P

Type

II

III

IV

V

Plaster brand

Manufacturer

Batch

Gesso Rio Mossoró Polidental Rutenium gesso 1 Gesso Rio Herodent Soli Rock K dent Pedra Mossoró Rutenium gesso 3 Durone IV G-4 Troquel Quatro Vel-Mix Durone V Rutenium gesso 5

OAB - ME, Rio Claro (SP)** Mossoró, Rio de Janeiro (RJ) Polidental, SP (SP) Rutenium, Queimados (RJ) OAB, Rio Claro (SP)** Vigodent, Rio de Janeiro (RJ) Quimidrol, Joinville (SC)** Mossoró, Rio de Janeiro (RJ) Rutenium, Queimados (RJ) Dentsply, Petrópolis (RJ) S S White, Rio de Janeiro (RJ) Polidental, SP (SP) Kerr Corporation, EUA Dentsply, Petrópolis (RJ) Rutenium, Queimados (RJ)

INP INP INP INP INP INP 014/0404 INP INP 41542 00E INP 3-22295 24123 INP

Recommended W/P INP INP INP 0.50-0.65 0.33 0.30 NC 0.35 0.30 0.19 0.18-0.21 0.19-0.21 0.20 0.19 0.19-0.21

Used W/P 0.50 0.50 0.50 0.50 0.33 0.30 0.33 0.35 0.30 0.19 0.21 0.21 0.20 0.19 0.21

INP = Information not provided

To make each specimen, 100±1 g of gypsum, weighed in an electronic scale Sauter K 1200, (August Sauter GmbH., Balingen, Germany), with accuracy of 0.01 g and capacity of 120 g, were mixed with the amount of deionized water corresponding to W/P recommended by the manufacturer; if the manufacturer did not provide this information, the general guideline for each plaster type was followed.

Firstly, the components were mixed with the aid of a metallic spatula, for 10 seconds and, then, with the aid of vacuum mixer VAC-U-VETOR, model B (WHIP-MIX, Louisville, KY, EUA), set at 22 mmHg of pressure, for 15 seconds. After that, the material was poured under vibration into the channel of the device coupled to the extensometer, up to the guide mark established by ADA [1] and ISO [5] Specifications and at a length of 10 cm.

The guide piece (mobile block) was fixed to the upper wing of the auxiliary rod, though a screw until the moment of the final vibration. The channel was covered by PTFE sheet of 0.1 mm of thickness (3M, Sumaré, SP, Brazil); the channel areas in touch with plaster were covered by solid Vaseline.

After the channel filling, other PTFE sheet was placed onto the surface of the fluid material to avoid

water evaporation from the fluid mixture. In order that the material length was 10 cm (100.000 µm) horizontally inside the channel, a 10-cm metallic guide cylinder was previously inserted inside it, after the locking of the guide piece through the screw on the rod above it.

The aforementioned expansion device together with the guide cylinder and the micrometric clock is shown in figure 1.

Figure 1 – Expansion device with the guide cylinder and the micrometric clock

64 – RSBO. 2015 Jan-Mar;12(1):61-7 Freitas et al. – Linear setting expansion of different gypsum products

The screw was released after 5 minutes (counting from the beginning of the mixture), for all specimens.

Thus, to establish the initial length, the micrometric clock pointer was adjusted to zero. The expansion values were recorded after more 120 minutes. The obtained data were converted in expansion percentage of the initial plaster length (10 cm), which is the length of the guide cylinder.

Results The observed values of the linear setting expansion of each specimen, followed by the mean and standard deviation values, for each plaster type, are seen in tables III, IV, V, and VI, respectively for types II, III, IV, and V. The last two columns of each table displays, respectively the percentage value of the expansion detected in this study, followed by that informed by the manufacturer.

Table III – Results of the linear setting expansion, in micrometers (µm), of five specimens from four type II dental plaster analyzed, followed respectively by the mean (m), standard deviation (sd), obtained expansion percentage (% oep) and informed expansion percentage (% info)

Brand Gesso Rio Mossoró Polidental Rutenium g1

1 257.5 275.0 251.5 212.0

2 165.0 272.0 254.0 310.0

Specimen 3 228.0 284.0 260.0 270.0

4 254.0 278.0 264.0 226.0

5 242.0 282.0 261.0 257.0

m

dp

% oep

% info

229.30 278.20 258.10 255.00

37.76 4.92 5.18 38.55

0.23 0.28 0.26 0.26

INP INP INP 0.25

INP = Information not provided

Table IV – Results of the linear setting expansion, in micrometers (µm), of five specimens from four type III dental plaster analyzed, followed respectively by the mean (m), standard deviation (sd), obtained expansion percentage (% oep) and informed expansion percentage (% info)

Brand Gesso Rio Herodent Soli-Ro K-Dent pedra Mossoró Rutenium g3

1 333.0 161.0 370.0 489.0 210.0

2 330.0 242.0 510.0 280.0 140.0

Specimen 3 356.0 321.0 470.0 346.0 228.0

4 282.0 287.0 495.0 296.0 202.0

5 321.0 267.0 482.0 325.0 206.0

m

dp

324.40 255.60 465.40 347.20 197.20

26.99 60.26 55.37 83.27 33.48

% oep % info 0.32 0.26 0.47 0.35 0.20

0.2-0.3 0.1-0.2 0.2-0.3 INP 0.30

INP = Information not provided

Table V – Results of the linear setting expansion, in micrometers (µm), of five specimens from four type IV dental plaster analyzed, followed respectively by the mean (m), standard deviation (sd), obtained expansion percentage (% oep) and informed expansion percentage (% info)

Brand Durone IV G-4 Troquel Quatro Vel-Mix

1 100.0 96.0 66.5 90.0

Specimen 2 3 109.0 109.0 94.0 102.0 66.0 76.0 99.0 101.0

4 107.0 104.0 72.0 91.0

5 110.0 98.0 68.0 96.0

m

dp

% oep

% info

107.00 98.80 69.70 95.40

4.06 4.15 4.24 4.83

0.11 0.10 0.07 0.10

0.09 O.08-0.10 0.09 0.04-0.08

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Table VI – Results of the linear setting expansion, in micrometers (µm), of five specimens from two type V dental plaster analyzed, followed respectively by the mean (m), standard deviation (sd), obtained expansion percentage (% oep) and informed expansion percentage (% info)

Brand

Specimen

m

dp

% oep

% info

232.0

242.26

23.78

0.24

0.20

190.0

191.10

2.25

0.19

0.30

1

2

3

4

5

Durone V

261.3

256.0

205.0

257.0

Rutenium g5

191.5

192.0

194.0

188.0

All analyzed type II dental stones met ISO [5] and ADA [1] Specifications. Concerning to types III, only “Rutenium gesso 3” met the limits. All type IV dental stones showed setting expansion lower than that required by the aforementioned associations, except for Durone IV, presenting a mean value 0.01% above ADA specification values, but within ISO specification values. The type V dental stones were within the required limits.

Discussion To evaluate the linear setting expansion of dental stone ADA [1] demands a series of specifications: the extensometer cited above must be used, the channel must be lined with a PTFE sheet, the fluid water/stone mass poured into the channel does not exceed the length of 36 cm, two markers (far between 30 cm) should be placed on the surface of the plaster and this exact distance must be assessed “1 minute before the setting time”; the distance ending must be checked 2 hours after dental stone manipulation. For the same purpose, ISO [5] demands the use of a extensometer, also comprising a similar channel whose material is not informed, with the aforementioned shapes and sizes, also covered by PTFE sheet; the channel must be closed by one of the endings by a fixed piece existing in the free ending of the mobile block. Immediately after the fluid mixture is poured into the channel, a micrometer should have the pointer touching the mobile block, moment when the ring should be rotated until its pointer is adjusted in the zero mark; reading which will be considered the initial and should be taken at 60±1 seconds before the final setting occurs, understood by another item explained in the Specification. The final measurement should be taken at 120±1 minutes, counting since the beginning of the mixture of the original components; the setting expansion should be calculated as the percentage of the original length, of about the second decimal, for at least two valid tests.

A careful reading of the standards referred herein supports the conclusion that they have essentially the same effect independent of the measuring device. The small differences between them are found, for example in expansion rates required for the different types of plasters.

In this study, we basically followed all of those requirements. The modification made to fix the movable part now allows the efficient vibration of the mixture (prior to leak in the channel) while maintaining the distance provided by the guide device.

Some companies provide confusing information, both on the labels of their products and in the respective package inserts and even in advertising materials. Often there is no indication of W/P ratio, manufacture date, batch number, and expiry date.

The names given to plaster by manufacturers often cause confusion. So that now difficulties were also detected in identifying the type of some products, according to the ADA specifications [1], as some manufacturers have created confusion, for example, placing the name of your product (trade name) as a type 1 plaster (in Arabic numerals), when such material is actually the type II (in Roman numerals, as shown in ADA specifications [1]).

Another serious problem is that related to the water/powder (W/P). Often this information is not included with the product, as already mentioned.

In many cases, when it exists and is followed, the minimum flow required by ADA is not achieved [1].

Then, the directions of the manufacturers were always followed regarding to the W/P ration. In the absence of this information, it was decided to use the mean value reported by other products of the same type, as long as the flowing appeared to be appropriate, during the act of pouring the material into the channel. By considering the results obtained and the percentage rates of the expansion allowed

by ADA [1] and ISO [5], the following conclusions can be made.

66 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):61-7 Freitas et al. â&#x20AC;&#x201C; Linear setting expansion of different gypsum products

Remembering that for dental stone called common (type II), for both cited specifications, a maximum of 0.30% is required. It was observed that only one of the analyzed stones (Ultra Herodent Cal) exceeded the limit.

For dental stone (type III), with both specifications mentioned requiring a maximum of 0.20%, it was observed that only one of the analyzed stone (Rutenium 3) met the requirements, having a lower expansion ratio than said in its packaging. All other stones of this type, in addition to having higher rates than required, had higher expansion rates than those contained in their packaging.

For high-strength stone (type IV), the first of the mentioned specifications is allowed a maximum of 0.10% and in the second, a maximum of 0.15%.

It was observed that almost all stones met the requirements, because Durone IV showed slightly more expansion than that required by ADA, but less than that required by ISO. For dental stone high strength and expansion (type V), the first specification required a maximum of 0.10%, while the second specification requires 0.15%. It was observed that both plasters exceed these limits and that the rate observed for Durone V was lower than that reported by the manufacturer, the opposite occurring for Rutenium gesso 5.

It is common knowledge that the stone types II and III are commonly used to obtain diagnostic models and working models, and this it is important containing minor dimensional changes [9].

By the same method used in this study, using the channel, Michalakis et al. [9] observed an expansion mean, considering type II dental stone after 2 hours, of 0.3 and 0.47% for Model Plaster (Heraeus Kulzer GmbH, Hanau, Germany) and Lab Plaster (Dentsply, Tulsa, OK, USA), respectively. In this present study, a mean of 0.23-0.28% was observed, compatible with the values of the aforementioned study. By considering the dental stone (type III), Michalakis et al. [9] obtained 0.15% as the result for linear expansion (Mounting Stone â&#x20AC;&#x201C; Whip Mix).

In this present study, we evaluated more products; however, they are different from those used in the study cited above; anyway, a mean between 0.2 and 0.47% of expansion.

At the beginning of mixing of the gypsum powder with water, there is a volumetric shrinkage [7]; over time, gypsite crystals are formed and an isotropic expansion can be observed [3, 12], which continues up to 120 hours [4], although the Specification n. 25 of ANSI/ADA [1] recommends the reading of the expansion for until 2 hours, the amount of time used in this study.

Type IV and V dental stones have been used in the process of construction of definitive restorations.

Thus, their dimensional stability is of fundamental importance for the final restoration outcome.

The results obtained by this present study agree with those of the study of Michalakis et al. [8], who evaluated the setting expansion of type IV and V dental stones, basically obtained the same results verified in this present study. Exemplifying, for VelMix, after 2 hours, a mean expansion of 0.09% was found in the study cited above, while this present study found 0.1%. In the assessment evaluated at 96 hours (by Michalakis et al.), Vel-Mix presented an expansion of 0. 15%, mostly occurring at the first 2 hours, but with a new expansion spurt after 24 hours; then a stability of about 3 weeks was seen, occasion in which the aforementioned authors detected the regress for the same expansion values observed after 2 hours (0.09%).

In type IV dental stones studied by Michalakis et al. [8], in 2012, the dimensional alteration varied from 0.07 to 0.09%, while in this present study the dimensional alteration was of 0.07 to 0.11%.

For the two type V dental stones, they observed a dimension alteration of 0.29 and 0.16%, respectively for Hard Rock and Jade Stone, both manufactured

by Whip Mix Corporation.

In this present study, it was observed an alteration of 0.24 and 0.19% for Durone V and Rutenium gesso 5, respectively. The similar results validate the different methods used in this present study and in the study of Michalakis et al. These authors used a metallic taper device with horizontal and vertical slots by using the optical microscope to evaluate the dimensional alterations.

It is vital to emphasize that this study closely followed the recommendations of the respective manufacturers, both regarding the dosage of the products and the handling process. As claimed

by Michalakis et al. [9], failure to follow these precautions changes the properties of the final product, especia lly as rega rds to t he water: powder proportion; the water excess increases the hygroscopic expansion, since it causes greater growth of gypsite crystals. The different expansion rates for different products reflect different qualities.

Conclusion Considering the limitations of this present study, and the limits established by ADA and ISO specifications, types II, IV, and V dental stones met the specifications, except for Durone IV. Considering type III dental stones, only Rutenium gesso 3 met the specifications.

It is need to constantly keep an assessment of the linear setting expansion of gypsum used in dentistry.

67 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):61-7 Freitas et al. â&#x20AC;&#x201C; Linear setting expansion of different gypsum products

Acknowledgements The authors thank Fapesp by the financial support (Process n. 03/02759-2).

References 1. American Dental Association. New American Dental Association specification n. 25 for dental gypsum products. J Am Dent Assoc. 1972 Mar;84(3):640-4.

2. Chang WG, Vahidi F, Bae KH, Lim BS. Accuracy of three implant impression techniques with different impression materials and stones. Int J Prosthodont. 2012 Jan-Feb;25(1):44-7.

3. Duke P, Moore BK, Haug SP, Andres CJ. Study of the physical properties of type IV gypsum, resincontaining, and epoxy die materials. J Prosthet Dent. 2000 Apr;83(4):466-73.

4. Heshmati RH, Nagy WW, Wirth CG, Dhuru VB. Delayed linear expansion of improved dental stone.

J Prosthet Dent. 2002 Jul;88(1):26-31.

5. International Organization for Standardization.

International standard ISO 6873 / Dental gypsum products. 2. ed. 1998.

6. Lautenschlager EP, Corbin F. Investigation on the expansion of dental stone. J Dent Res. 1969 Mar-Apr;48(2):206-10.

7. Mahler DB, Ady AB. An explanation for the hygroscopic setting expansion of dental gypsum products. J Dent Res. 1960 May-Jun;39:578-89.

8. Michalakis KX, Asar NV, Kapsampeli V, Magkavali-Trikka P, Pissiotis AL, Hirayama H. Delayed linear dimensional changes of five high strength gypsum products used for the fabrication of definitive casts. J Prosthet Dent.

2012 Sep;108(3):189-95.

9. Michalakis KX, Stratos A, Hirayama H, Pissiotis AL, Touloumi F. Delayed setting and hygroscopic linear expansion of three gypsum products used for cast articulation. J Prosthet Dent. 2009 Nov;102(5):313-8.

10. Pal PK, Kamble SS, Chaurasia RR, Chaurasia VR, Tiwari S, Bansal D. Evaluation of different disinfactants on dimensional accuracy and surface quality of type IV gypsum casts retrieved from elastomeric impression materials. J Int Oral Health. 2014 Jun;6(3):77-81.

11. Vigolo P, Fonzi F, Majzoub Z, Cordioli G. An evaluation of impression techniques for multiple internal connection implant prostheses. J Prosthet Dent. 2004 Nov;92(5):470-6.

12. Winkler MM, Monaghan P, Gilbert JL, Lautenschlager EP. Comparison of four techniques for monitoring the setting kinetics of gypsum. J Prosthet Dent. 1998 May;79(5):532-6.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):68-78

Literature Review Article

Developmental anomalies affecting the morphology of teeth – a review Ashish Shrestha1 Vinay Marla1 Sushmita Shrestha2 Iccha K Maharjan3 Corresponding author: Ashish Shrestha Department of Oral Histology and Pathology, College of Dental Surgery B. P. Koirala Institute of Health Sciences Dharan – Sunsari – Nepal E-mail: ashish.shrestha@bpkihs.edu Department of Oral Histology and Pathology, College of Dental Surgery, B. P. Koirala Institute of Health Sciences – Dharan – Nepal.

2 Department of Conservative Dentistry and Endodontics, College of Dental Surgery, B. P. Koirala Institute of Health Sciences – Dharan – Nepal.

3 Department of Oral Medicine and Radiology, College of Dental Surgery, B. P. Koirala Institute of Health Sciences – Dharan – Nepal.

1

Received for publication: May 5, 2014. Accepted for publication: August 12, 2014.

Keywords: developmental anomaly, diagnostic criteria, tooth morphology.

Abstract Introduction: The development of tooth is a complex process wherein there is series of interactions between the ectoderm and ectomesenchyme. The role of genes in determining the shape and form of a specific tooth has already been defined, the alterations in which can lead to a variety of anomalies in regards to number, size, form, shape, structure, etc. Objective: To review the literature on the developmental anomalies of teeth. Literature review: The developmental anomalies affecting the morphology exists in both deciduous & permanent dentition and shows various forms such as gemination, fusion, concrescence, dilacerations, dens evaginatus, dens invaginatus, enamel pearls, taurodontism or peg laterals. These anomalies have clinical significance concerning esthetics, malocclusion and more importantly predisposing the development of dental caries and periodontal diseases. Conclusion: Knowledge of various diagnostic criteria for identification of these developmental anomalies is significant for early diagnosis and pertinent treatment.

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Introduction The tooth is a specialized part of the human body, understanding the development of which is enigmatic and still challenging. The successful development of toot h depends on a complex reciprocal interaction between the dental epithelium and underlying ectomesenchyme. The interaction involves a complex series of molecular signals, receptors and transcription control systems [73].

Anomaly (Gk, anomalos; irregular) is a deviation from what is regarded as normal [48]. Disturbance of the epithelium and mesenchymal interactions can markedly alter the normal odontogenesis leading to the developmental anomaly of teeth. Depending on the developmental stage in which the alteration has taken place, different anomalies could take place e.g. anomalies of number, structure, size and/or shape [46].

Developmental dental anomalies are marked deviations from the normal color, contour, size,

number, and degree of development of teeth. Local as well as systemic factors may be responsible for these developmental disturbances. Such influences may begin before or after birth, hence both the dentition might be affected [12].

More than 300 genes have been known to be expressed in teeth that are responsible for odontogenesis [72]. Defects in these genes have been found to be one of the reasons for alteration of the morphology of tooth [72].

World Health Organization (WHO) has classified “the diseases of oral cavity, salivary glands and jaws” in WHO-International Classification of Disease -10 (WHO-ICD-10) (K00-K14) [23]. The anomalies of tooth size and form has been listed under section WHO-ICD -10 (K00.2), which includes concrescence, fusion, gemination, dens evaginatus, dens in dente, dens invaginatus, enamel pearls, macrodontia, microdontia, peg-shaped teeth, taurodontism and tuberculum paramolare (figures 1 and 2).

Figure 1 – Developmental alterations of tooth morphology. (a. Root dilaceration of mandibular molar; b. Concrescence between mandibular first and second molar; c. Talons’ cusp on the labial aspect of maxillary lateral incisor; d.

Crown dilaceration of maxillary central incisor; e. Taurodontism in maxillary second molar; f. Enamel pearl on buccal aspect of mandibular third molar) (Achieves of department of Oral Histology and Pathology, BPKIHS)

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Figure 2 – Radiograph of dental anomalies. (a. Root dilaceration of mandibular molar; b. Talons’ cusp lined by enamel containing core of dentin and pulp in maxillary lateral incisor; c. Fusion of root between mandibular second and third molar; d. Crown dilaceration of maxillary central incisor; e. Concrescence between mandibular first and second molar with dens evaginatus; f. Enamel pearl seen as radio-opaque foci near the furcation area)

Understanding the etiology of each dental anomaly is important not only in identification but also to determine the course of the treatment. So, we aim to review the literature regarding various anomalies affecting the tooth and the criteria laid down for its diagnosis.

Description of the anomalies Gemination Ta nnenbaun a nd A lling in 1963 defined gemination as the formation of equivalent of two teeth from the same follicle, with evidence of an attempt for the teeth to be completely separate [71].

Gemination also described as double teeth, double formations, joined teeth, fused teeth or dental twinning is commonly seen in the maxillary anterior region [17, 62].

Geminated teeth arise from an attempt at division of a single tooth germ by invagination, resulting in a single tooth with two completely separated crowns; or a large, incompletely separated crown having single root and root canal [55],

which can be confirmed radiographically [68].

The anomalous tooth has a larger mesial-distal diameter than normal and is counted as one [33, 68]. However the total number of teeth in dental arch is otherwise normal [68].

The etiolog y of geminated teet h remains unknown but nutritional deficiency, endocrine inf luences, infectious/inf lammatory processes, excessive ingestion of medicines, hereditary or congenital diseases, local trauma and ionizing radiation are considered as causative factors [62].

Clinically, gemination occurring in the anterior tooth region causes esthetic problems related to tooth alignment, spacing and arch asymmetry. The presence of deep grooves on the surface makes it susceptible to caries and periodontal problems by facilitating bacterial plaque accumulation. The eruption of adjacent tooth may also be impeded [55].

Fusion Pindborg defined fusion as the union between dentin a nd ena mel of t wo or more sepa rate developing teeth [54]. There may be complete union

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to form one abnormally large tooth; union of crowns or union of roots only [47]. This anatomic irregularity occurs more often in deciduous dentition with a predilection for the anterior region [68].

Fusion can be complete (total/true fusion) or incomplete (partial/late fusion), depending on stage of development [33, 68]. If fusion begins before calcification stage, the teeth unite completely and the crown incorporates enamel, dentin, cementum and pulp of both the teeth. Incomplete fusion occurs at a later stage and resultant tooth may exhibit separate crowns and limited to root alone with fused or separate pulp canals. The tooth count reveals a missing tooth where anomalous tooth is counted as one [68], unless where the fusion is occurring with a supernumerary tooth [47].

Various theories have been put forward to explain the etiology of fusion. It has been suggested that when the tooth germs are close together they come in contact and fuse as they develop due to the physical pressure or force generated during grow th. Other theories sug gested the use of thalidomide or occurrence of viral infection during pregnancy [32]. A genetic etiology has also been considered [51]. Fusion has been reported with congenital anomalies like cleft lip and also in Xlinked congenital conditions. Some dental and non dental abnormalities including supernumerary teeth, hypodontia, peg-shaped incisors, dens in dente, nail disorders, syndactyly, successional conical teeth, macrodontia and double permanent teeth have been associated with fusion [6, 65].

Fusion may cause aesthetic problems and occlusal disturbances due to crowding and irregular morphology, respectively. The presence of deep grooves may predispose to caries or periodontal diseases and cause early pulp exposure. The greater root mass and increased surface area would result in delayed resorption and subsequently cause delayed or ectopic eruption of the permanent successors [47, 68].

Concrescence Concrescence is defined as the cemental union of two adjacent teeth without confluence of the underlying dentin showing independent pulp chambers and root canals [14, 18]. It may occur during or after the completion of root formation. If the condition occurs during development, it is called true/developmental concrescence and acquired/post inflammatory concrescence if after root formation [18, 42].

Concrescence is seen frequently in the posterior maxillary region. The developmental pattern often involves a second molar tooth in which its roots closely approximate to the adjacent impacted third molar [70]. Few cases have shown the concrescence of a third molar and a supernumerary tooth [18].

It is suspected that space restriction during development, local trauma, excessive occlusal force, or local infection after development play an important role in the occurrence of concrescence [18, 31]. True concrescence is attributed to the close proximity of developing roots of the adjacent teeth whereas acquired concrescence may result from a chronic inflammatory response to a non-vital tooth [42]. The union may vary from one small site to a solid cemental mass along the entire extent of approximating root surfaces [18].

Radiographic examination is required when concrescence is suspected clinically. However in cases of superimposition of two closely approximated teeth, additional radiographic projections at different angulations may be required [18].

Concrescence should be carefully identified to reduce the risk of complications associated with surgical procedures [31]. It may affect the extraction of an adjacent tooth and may fracture the tuberosity or f loor of the maxillary sinus. In such cases, sectioning of tooth should be considered to minimize adverse and unexpected outcomes [42].

Dilaceration The term dilaceration was first used by Tomes [75] in 1848 and is defined as a deviation or bend in the linear relationship of crown of a tooth to its root [74]. It has been listed under section K00.4 of WHO ICD-10 [23].

Dilacerations usually occur in the apical third of the root when the anterior teeth are involved, middle third when first molars are involved and coronal third when third molars are involved [39].

Root dilacerations are common than crown dilacerations and occur usually in the posterior region of permanent dentition [25]. However crown dilacerations are commonly observed in the permanent ma xillary incisors followed by mandibular incisors. Clinically, the maxillary incisors show a ling ua l dev iat ion while t he mandibular incisors incline labially. Pulp necrosis and periapical inflammation may be a common finding even in the absence of decay because the bent portion acts as a nidus for bacterial entry due to defective enamel and dentin [3]. Some syndromes and developmental anomalies such as

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Smith Magenis syndrome, hypermobility type of Ehlers-Danlos syndrome, Axenfeld-Rieger syndrome, and congenital ichthyosis have been associated with dilaceration [25, 76].

Mechanical trauma (Eg: laryngoscopy and endotracheal intubation) to the primary predecessor tooth is thought to be the most probable cause which results in dilaceration of the crown of developing succedaneous permanent tooth [3, 25]. The calcified portion of the permanent tooth germ is displaced in such a way that the remainder of the tooth germ forms at an angle [78]. Although the prevalence of traumatic injuries to the primary dentition ranges from 11-30%, the incidence of dilacerated permanent teeth is very low [25].

Other possible contributing factors that have been reported include scar formation, developmental anomaly of the primary tooth germ, facial clefting, advanced root canal infections, ectopic development of the tooth germ and lack of space, effect of anatomic structures (Eg. cortical bone of the maxillary sinus, mandibular canal, or nasal fossa, which might deflect the epithelial diaphragm), presence of an adjacent cyst, tumor, or odontogenic hamartoma, mechanical interference with eruption (Eg. from an ankylosed primary tooth that does not resorb), tooth transplantation, extraction of primary teeth, and hereditary factors [25, 27, 69, 76].

There are varying schools of thoughts regarding the criteria for diagnosing root dilacerations.

Hamasha et al have considered dilacerations of root toward the mesial or distal direction, if there is a 900 or greater deviation along the axis of the tooth or root, whereas Chohayeb et al have considered a deviation of 20 0 or more in the apical part of the root [8, 21]. Chohayeb et al in their study have reported maxillary lateral incisors to be the most commonly dilacerated tooth which could be due to the consideration of distal curvature of the apical third of root as dilaceration rather than a normal anatomy [8, 25].

The recognition and diagnosis of dilaceration often requires radiographs taken at va rious angulations [26]. Mesial or distal root curvatures of dilacerated roots are clearly discernible on periapical radiographs. However if the curvature lies in a labial-buccal direction, the central X-ray beam passes almost parallel to the deviating part of the root giving a ‘bulls eye’ like appearance [76].

Clinical recognition of dilaceration is important because it can lead to non eruption, longer retention of primary predecessor tooth or possible apical fenestration of the buccal or labial cortical plate

[76]. Dilaceration causes a challenge for endodontic or orthodontic treatment as well as difficulty in extraction [25, 39, 76].

Dens invaginatus Dens invaginatus (DI) also known as the pregnant woman anomaly, extensive compound odontoma, and dens in dente, occurs as a consequence of an invagination on the external surface of the tooth crown before calcification [4, 28]. The invagination ranges from a short pit confined to the crown to a deep invagination into the root, at times extending to or beyond the root apex. The most severe forms are odontome-like and are often termed invaginated odontomes [37]. Majority of the cases are encountered in maxilla with the maxillary lateral incisors being commonly affected, followed by central incisors, premolars, canines and molars [20, 28].

The classical radiographic appearance of coronal DI is a pear shaped invagination of enamel and dentin with a narrow constriction at the opening on the surface of the tooth. The infolding of the enamel lining is more radio-opaque than the surrounding tooth structure aiding easy identification [50].

Oehlers et al grouped coronal DI into three types according to the radiographic appearance [52]: • Type I: An enamel-lined minor form occurring within the confines of the crown not extending beyond the cemento-enamel junction; • Type II: An enamel-lined form which invades the root but remains confined as a blind sac. It may or may not communicate with the dental pulp; • Type III A: A form which penetrates through the root and communicates laterally with the periodontal ligament space through a pseudo-foramen. There is usually no communication with the pulp, which lies compressed within the root; • TYPE III B: A form which penetrates through the root and perforating at the apical area through a pseudo-foramen. The invagination may be completely lined by enamel, but frequently cementum will be found lining the invagination.

A radicular form of dens invaginatus has also been described by Oehlers which is thought to arise due to the proliferation of Hertwig’s root sheath.

The root of such tooth is enlarged which can be demonstrated radiographically [53].

Infection, trauma or pressure from the growing dental arch is thought to be responsible for dens invaginatus [4, 19]. A focal failure of growth or a proliferation of a part of the inner enamel epithelium may be involved in the invagination [34, 61]. Ohlers

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suggested a distortion of the enamel organ and subsequent protrusion of a part of the enamel organ resulting in the formation of an enamel lined channel [52].

The invagination acts as a channel for entry of irritants and microorganisms; and predispose to the development of dental caries. Since the thickness of enamel is less, pulp necrosis occurs at an earlier age. Coronal DI can also lead to abscess formation, retention of neighboring teeth, cysts, internal resorption, cellulitis etc. [49].

Dens evaginatus Dens evaginatus (DE) is a developmental aberration of a tooth resulting in formation of an accessory cusp whose morpholog y has been described as abnormal tubercle, elevation, protuberance, excrescence, extrusion, or a bulge [36].

It is also referred to as tuberculated cusp, accessory tubercle, occlusal tuberculated premolar, Leong’s premolar, evaginatus odontoma, and occlusal pearl [11, 36]. Currently, dens evaginatus is the preferred terminology and was first recommended by Oehlers in 1967 [52]. This uncommon anomaly projects above the adjacent tooth surface, exhibiting enamel covering a dentinal core that usually contains pulp tissue; occasionally having slender pulp horn which extends to various distances within the dentinal core [36, 77]. The tubercles of dens evaginatus has been differentiated from the cusp of carabelli which is a normal anatomical finding and is differentiated from DE by the absence of a pulp core [36].

A multifactorial etiology combining both genetics and environmental factors has been suggested for the formation of dens evaginatus. Mutations in the human EDA1, EDAR, and EDARADD genes often result in more severe phenotypes resulting in tooth loss and malformation [44]. It occurs during the bell stage and is characterized by abnormal proliferation of inner enamel epithelium into the stellate reticulum of the enamel organ [11].

The occurrence of dens evaginatus shows great racial differences with a higher prevalence among people of Mongoloid origin [81]. It is commonly associated with the occlusal surface of premolars.

Schulze (1987) distinguished the following five types of DE for posterior teeth by the location of the tubercle [36, 64].

1. A cone-like enlargement of the lingual cusp; 2. A tubercle on the inclined plane of the lingual cusp;

3. A cone-like enlargement of the buccal cusp; 4. A tubercle on the inclined plane of the buccal cusp; 5. A tubercle arising from the occlusal surface obliterating the central groove.

When dens evaginatus appears in the anterior region, it is usually observed on the lingual surface and is described as a Talon’s cusp [36]. Mitchell was the first to recognize this anomaly in 1892, which was later named talon by Mellor and Ripa due to its resemblance to an eagle’s talon [43, 45]. It is commonly seen in the maxillary lateral incisors and has been associated with syndromes such as Rubinstein and Taybi, Berardinelli-Seip, Mohr, Ellis-van Creveld, Sturge-Weber and incontinentia pigmenti achromians [67]. It varies in size, shape, length and mode of attachment to the crown and ranges from an enlarged cingulum to a large, welldelineated cusp extending beyond the incisal edge of the tooth [37]. The cusp is composed of normal enamel and dentin containing varying extensions of pulp tissue. It may connect with the incisal edge to produce a T-form or, if more cervical, a Y-shaped crown contour [20].

Hattab et al classified talons’ cusps into three types based on the degree of cusp formation and extension [22]: • Type 1: Talon – refers to a morphologically well-delineated additional cusp that prominently projects from the palatal (or facial) surface of a primary or permanent anterior tooth and extends at least half the distance from cemento-enamel junction to the incisal edge; • Type 2: Semi talon – refers to an additional cusp of a millimeter or more extending less than half the distance from cemento-enamel junction to the incisal edge. It may blend with the palatal surface or stand away from the rest of the crown; • Type 3: Trace talon – an enlarged or prominent cingula and their variations, i.e. conical, bifid or tubercle-like.

The dens evaginatus or talons cusp may fracture or be abraded as soon as the tooth comes into occlusion, exposing the pulp [11].

Hence early recognition of this anomaly and prompt treatment should be instituted to prevent endodontic complications.

Enamel pearls Enamel which is normally restricted to the anatomic crowns of human teeth may be found

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ectopically on the root, either as cervical enamel projections or enamel pearls [59, 60]. Enamel pearl is defined as an ectopic globule of enamel that is firmly attached to the tooth root [9]. According to Kupietzky and Rozenfarb (1993) the enamel pearl anomaly was first described in 1824 by Linder and Linder [35]. It has been referred to as an enameloma, enamel droplet, enamel nodule, enamel exostoses and enamel globule. It is found commonly on the roots of maxillary molars, especially the third molars adjacent to the furcation or furrow of the root [60].

The structure of the enamel in ectopic enamel projections are characterized as normal, but with considerable variations and irregular features that are most likely related to its ectopic development [58]. During normal tooth development, ameloblasts lose their activity after crown formation and become part of Hertwig’s epithelial root sheath. Occasionally for unknown reasons, ameloblasts retain their enamel competence, resulting in prolonged (cervical enamel projections) or delayed (enamel pearls) ectopic enamel production [15].

Advanced localized periodontal destruction has been associated with cervical enamel projections and enamel pearl, predisposing to attachment loss [2].

Taurodontism Witkop defined taurodontism as teeth with large pulp chambers in which the bifurcation or trifurcation are displaced apically, so that the chamber has greater apical-occlusal height than in normal teeth and lacks the constriction at the level of cemento-enamel junction (CEJ). The distance from the trifurcation or bifurcation of the root to the CEJ is greater than the occlusal-cervical distance [79].

This anomaly was first reported in the remnants of prehistoric hominids by de Terra in 1903 and

by Gorjanovic - Kramberger and Aldoff in 1907 [16]. Pickerill in 1909 noted this in modern man [41]. However the term “taurodontism” was first used by Sir Arthur Keith in 1913 to describe the teeth of prehistoric people, the Neanderthals and Heidelberg [30]. He coined this term from the Latin word tauro (for bull) and Greek term dont (for tooth) because of the morphological resemblance of affected tooth to the tooth of ungulates or cud chewing animals.

Shaw (1928) has classified taurodontism arbitrarily based on relative degree of apical displacement of floor of pulp chamber into hypo, meso and hyper-taurodontism (figure 3) [66]. Various diagnostic criteria have been put forward for the identification of taurodontism which has been summarized in table 1 [5, 13, 29, 63].

Figure 3 – Schematic representation of taurodontism. (a. Cynodont; b. According to Blumberg et al.; c. According to Shifman and Chanannel; d. According to Shaw; hypo-taurodontism, meso-taurodontism, hyper-taurodontism [from left to right])

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Table I – Criteria for identification of taurodontism [68-71]

Authors (Year) Keene (1966)

Criteria

Categories

• Taurodont Index; related to the height of the pulp • Cynodont: Index value 0-24.9% chamber to the length of the longest root.

• Hypo-T*: Index value 25-49.9% • Meso-T: Index value 50-74.9% • Hyper-T: Index value 75-100%

Blumberg et al.

• Variable 1: mesial-distal diameter taken at (1971) contact points • Variable 2: mesial-distal diameter taken at the level of the cemento enamel junction • Variable 3: perpendicular distance from baseline to highest point on pulp chamber oor • Variable 4: perpendicular distance from baseline to apex of longest root • Variable 5: perpendicular distance from baseline to lowest point on pulp chamber roof.

Feichtinger and Rossiwall (1977)

• Distance from the bifurcation or trifurcation of the root to the cemento-enamel junction (CEJ) should be greater than occlusal-cervical distance for a taurodontic tooth

Shifman and Chanannel (1978)

Formulated a mathematical index which is adopted well till the present day.

• Point A: lowest point at the occlusal end of the pulp chamber • Point B: highest point at the apical end of the pulp chamber • Distance from A to B divided by distance from A to the apex of the longest root is equal to or greater than 0.2mm, and • Distance from B to CEJ is greater than or equal to 2.5mm

• No categories provided, as the authors believe that taurodontism is a continuous trait and therefore cannot be put into strict categories.

(Figure 3b)

• Hypo-T: 20–20.9% • Meso-T: 30–39.9% • Hyper-T: 40–75% (Figure 3c)

* T – taurodontism

Taurodontism primarily affects the molar teeth [38]. It occurs as isolated cases but also has been associated with other anomalies. It has been reported in Klinefelter's syndrome, Down's syndrome, Trichodento osseous syndrome, orofacial digital syndrome, Mohr Syndrome or ectodermal dysplasia. It has a lso been associated w it h amelogenesis imperfecta, cleft palate, microdontia and dens invaginatus [24, 26, 41, 80].

The etiology of taurodontism is still uncertain, but it is thought to be caused by the failure of Hertwig's sheath to invaginate at the proper horizontal level but other possible etiologies have to be considered including spontaneous mutation and the influence of additional factors such as infection, on the developing tooth [40, 57].

Severa l clinica l considerations would be associated with the management of teeth with taurodontism. Extensive length of pulp chambers might create difficulty in location of root canals.

Taurodontic molars are suggested to have less resistance to lateral displacing forces compared to cynodont due its smaller surface area and hence are not used as an abutment [40].

Peg shaped laterals A peg latera l is a n undersized, tapered, maxillary lateral incisor [10]. The tooth is conical in shape; broadest cervically and tapers incisally to a blunt point. An unusual occurrence is that of a peg-shaped maxillary central incisor. Peg-

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shaped teeth develop from a single lobe instead of four. The peg-shaped laterals are predominantly genetically determined and can also be caused due to endocrinal disturbances [7]. Peg-shaped laterals may be associated with other dental anomalies such as tooth agenesis, canine transposition and overretained deciduous teeth. Studies of identical twins have indicated that missing teeth and peg-shaped lateral incisor might be a varied expression of the same genetic trait [1, 10]. Early management of the peg-shaped laterals is necessary due to psychological problems in children as well as for the proper development of the stomatognathic system [7].

Conclusion Although asymptomatic, these dental anomalies ca n lead to clinica l problems which include delayed or incomplete eruption of the normal series of teeth, attrition, compromised esthetics, occlusal interference, accidental cusp fracture, interference with tongue space causing difficulty in speech and mastication, temporomandibular joint pain and dysfunction, malocclusion, periodontal problems and increased susceptibility to caries. The developmental anomalies of teeth show variations and no two anomalies of the same type are alike. So knowledge of various criteria which have been put forward for the identification and classification of the different anomalies is essential to diagnose the condition and institute appropriate treatment.

References 1. Amin F, Asif J, Akber S. Prevalence of peg laterals and small size lateral incisors in orthodontic patients-a study. Pakistan Oral and Dental Journal.

2011;31:88-91.

2. Askenas BG, Fry HR, Davis JW. Cervical enamel projection with gingival fenestration in a maxillary central incisor: report of a case. Quintessence Int. 1992;23:103-7.

3. Asokan S, Rayen R, Muthu M, Sivakumar N. Crown dilacerations of maxillary right permanent central incisor – a case report. J Indian Soc Pedo Prev Dent. 2004;22:197-200.

4. Atkinson SR. The permanent maxillary lateral incisor. Am J Orthod. 1943;29:685-98.

5. Blumberg JE, Hylander WL, Goepp RA. Taurodontism: a biometric study. Am J Phys Anthropol. 1971;34:243-55.

6. Brook AH, Winter GB. Double teeth. A retrospective study of “geminated” and “fused” teeth in children. Br Dent J. 1970;129:123-30.

7. Chanchala HP, Nandlal B. Coexistent peg shaped mandibular central incisors along with maxillary lateral incisors: a rare case. International Journal of Oral & Maxillofacial Pathology. 2012;3:65-8.

8. Chohayeb AA. Dilaceration of permanent upper lateral incisors: frequency, direction, and endodontic treatment implications. Oral Surg Oral Med Oral Pathol. 1983;55:519-20.

9. Darwazeh A, Hamasha AA. Radiographic evidence of enamel pearls in Jordanian dental patients. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2000;89:255-8.

10. Deshpande A, Macwan C. Clinical management of rudimentary supernumerary tooth and pegshaped lateral incisor: a case report. RRJDS. 2013;1:1-4.

11. Echeverri EA, Wang MM, Chavaria C, Taylor DL. Multiple dens evaginatus: diagnosis, management, and complications: case report. Pediatr Dent.

1994;16:314-7.

12. Ezoddini AF, Sheikhha MH, Ahmadi H. The prevalence of dental developmental anomalies: a radiographic study. Community Dent Health.

2007;24:140-4.

13. Feichtinger C, Rossiwall B. Taurodontism in human sex chromosome aneuploidy. Arch Oral Biol. 1977;22:327-9.

14. Foran D, Komabayashi T, Lin LM. Concrescence of permanent maxillary second and third molars: case report of non-surgical root canal treatment.

J Oral Sci. 2012;54:133-6.

15. Goldstein AR. Enamel pearls as contributing factor in periodontal breakdown. J Am Dent Assoc.

1979;99:210-1.

16. Gorjanovic-Kramberger K. Uber prismatische molarwurzeln rezenter und diluvialer Menschem.

Anat Anz. 1908;32:401-30.

17. Guimarães CLA, Firoozmand LM, Dias Almeida J. Double teeth in primary dentition: report of two clinical cases. Med Oral Patol Oral Cir Bucal.

2008;13:E77-E80.

18. Gunduz K, Sumer M, Sumer AP, Gunhan O. Concrescence of a mandibular third molar and a supernumerary fourth molar: report of a rare case.

Br Dent J. 2006;200:141-2.

77 – RSBO. 2015 Jan-Mar;12(1):68-78 Shrestha et al. – Developmental anomalies affecting the morphology of teeth – a review

19. Gustafson G, Sundberg S. Dens in dente. Br Dent J. 1950;8:83-8,111-22,144-6.

20. Guttal KS, Naikmasur VG, Bhargava P, Bathi RJ. Frequency of developmental dental anomalies in the Indian population. European Journal of Dentistry. 2010;4:263-9.

21. Hamasha AA, Al-Khateeb T, Darwazeh A. Prevalence of dilaceration in Jordanian adults. Int Endod J. 2002;35:910-2.

22. Hattab FN, Yassin OM, Al-Nimri KS. Talon cusp in the permanent dentition associated with other dental anomalies: Review of literature and reports of seven cases. J Dent Child. 1996;63:368-76.

23. International Statistical Classification of Diseases and Related Health Problems. 10 th Revision (ICD-10). Version for 2010. Available from: URL:http://apps.who.int/classifications/ icd10/browse/2010/en#/K07.3.

33. Knezevic A, Travan S, Tarle Z, Sutalo J, Jankovic B, Ciglar I. Double tooth. Coll Antropol.

2002;26:667-72.

34. Kronfeld R. Dens in dente. J Dent Res. 1934;14:49-66.

35. Kupietzky A, Rozenfarb N. Enamel pearls in the primary dentition: report of two cases. ASDC J Dent Child. 1993;60:63-6.

36. Levitan ME, Himel VT. Dens evaginatus: literature review, pathophysiology, and comprehensive treatment regimen. J Endod. 2006;32:1-9.

37. Lorena SC, Oliveira DT, Odellt EW. Multiple dental anomalies in the maxillary incisor region.

J Oral Sci. 2003;45:47-50.

38. Madeira MC, Leite HF, Filho WDN, Simoes S. Prevalence of taurodontism in premolars. Oral Surg Oral Med Oral Patol. 1986;61:158-62.

24. Ireland EJ, Black JP, Scures CC. Short root, taurodontia and multiple dens invaginatus. J Pedod. 1987;11:164-75.

39. Malcic A, Jukic S, Brzovic V, Miletic I, Pelivan I, Anic I. Prevalence of root dilacerations in adult dental patients in Croatia. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006;102:104-9.

25. Jafarzadeh H, Abbott PV. Dilaceration: review of an endodontic challenge. J Endod.

2007;33:1025-30.

40. Mangion JJ. Two cases of taurodontism in modern human jaws. Br Dent J. 1962;113:30912.

26. Jafarzadeh H, Azarpazhooh A, Mayhall JT. Taurodontism: a review of the condition and endodontic treatment challenges. Int Endod J. 2008;41:375-88.

41. Mark T, Jaspers MT. Taurodontism in Down’s syndrome. Oral Surg. 1981;51:632-6.

27. Kalra N, Sushma K, Mahapatra GK. Changes in developing succedaneous teeth as a consequence of infected deciduous molars. J Indian Soc Pedod Prev Dent. 2000;18:90-4.

43. Mellor JK, Ripa LW. Talon cusp: a clinically significant anomaly. Oral Surg Oral Med Oral Pathol. 1970;29:225-8.

28. Karjodkar FR, Mali S, Sontakke S, Sansare K, Patil DJ. Five developmental anomalies in a single patient: a rare case report. Journal of Clinical and Diagnostic Research. 2012;6:1603-5.

29. Keene HJ. A morphologic and biometric study of taurodontism in a contemporary population. Am J Phys Anthropol. 1966;25:208-9.

30. Keith A. Problems relating to the teeth of the earlier forms of prehistoric man. Proc R Soc Med. 1913;6:103-10.

31. Khanna S, Sandhu SV, Bansal H, Khanna V. Concrescence – a report of two cases. International Journal of Dental Clinics. 2011;3:75-6.

32. Kjaer I, Daugaard-Jensen J. Interrelation between fusions in the primary dentition and agencies in the succedaneous permanent dentition seen from an embryological point of view. J Craniofac Genet Dev Biol. 2000;20:193-7.

42. Meer Z, Rakesh N. Concrescence in primary dentition: a case report. IJCDS. 2011;2:19-21.

44. Miletich I, Sharpe PT. Normal and abnormal dental development. Hum Mol Genet. 2003;12(Spec No 1):R69-73.

45. Mitchell WH. Case report. Dental Cosmos.

1982;34:1036.

46. Mohapatra A, Prabhakar A, Raju O. An unusual triplication of primary teeth: a rare case report.

Quintessence Int. 2010;41:815-20.

47. More CB, Tailor MN. Tooth fusion, a rare dental anomaly: analysis of six cases. International Journal of Oral and Maxillofacial Pathology.

2012;4:50-3.

48. Mosby’s Medical Dictionary. 8. ed. Elsevier; 2009.

49. Munir B, Tirmazi SM, Majeed HA, Khan AM, Iqbalbangash N. Dens invaginatus: aetiology, classification, prevalence, diagnosis and treatment considerations. Pakistan Oral and Dental Journal.

2011;31:191-8.

78 – RSBO. 2015 Jan-Mar;12(1):68-78 Shrestha et al. – Developmental anomalies affecting the morphology of teeth – a review

50. Mupparapu M, Singer SR. A rare presentation of dens invaginatus in a mandibular lateral incisor occurring concurrently with bilateral maxillary dens invaginatus: case report and review of literature. Aust Dent J. 2004;49:90-3.

51. Nik-Hussein NN, Abdul Majid Z. Dental anomalies in the primary dentition: distribution and correlation with the permanent dentition. J Clin Pediatr Dent. 1996;21:15-9.

52. Oehlers FA, Lee KW, Lee EC. Dens evaginatus, its structure and responses to external stimuli.

Dent Pract. 1967;17:239-44.

53. Oehlers FA. The radicular variety of dens invaginatus. Oral Surg Oral Med Oral Pathol.

1958;11:1251-60.

54. Pindborg JJ. Pathology of the dental hard tissues. Philadelphia: W.B. Saunders; 1970.

55. Rajeshwari MR, Ananthalakshmi R. Gemination – case report and review. Indian Journal of Multidisciplinary Dentistry. 2011;1:355-6.

56. Rao PK, Veena KM, Chatra L, Shenai P. Twins on either side – a case report of bilateral gemination.

Open Access Scientific Reports. 2012;1:1-2.

57. Reichart P, Quast U. Mandibular infection as a possible aetiogical factor in taurodontism. J Dent.

1975;3:198-202.

58. Risnes S. Ectopic tooth enamel. An SEM study of the structure of enamel in enamel pearls. Adv Dent Res. 1989;3:258-64.

59. Risnes S. The prevalence and distribution of cervical enamel projections reaching into the furcation on human molars. Scand J Dent Res. 1974;82:413-9.

60. Risnes S. The prevalence, location, and size of enamel pearls on human molars. Scand J Dent Res. 1974;82:403-12.

61. Rushton MA. A collection of dilated composite odontomas. Br Dent J. 1937;63:65-85.

62. Santos KSA, Lins CCSA, Almeida-Gomes F, Travassos RMC, Santos RA. Anatomical aspects of permanent geminate superior central incisives.

Int J Morphol. 2009;27(2):515-7.

63. Schifman A, Chanannel I. Prevalence of taurodontism found in radiographic dental examination of 1200 young adult Israeli patients.

Community Dent Oral Epidemiol. 1978;6:200-3.

64. Schulze Ch. Anomalien und Missbildungen der menschlichen. Zähne Quintessenz Verlags GmbH. 1987:94-101.

65. Sekerci AE, Sisman Y, Yasa Y, Sahman H, Ekizer A. Prevalence of fusion and gemination in permanent teeth in Coppadocia region in Turkey.

Pakistan Oral & Dental Journal. 2011;31:17-22.

66. Shaw JC. Taurodont teeth in South African races. J Anat. 1928;62:476-98.

67. Shirazi AS, Rezaiefar M, Forghani M. A rare case of multiple talon cusps in three siblings. Braz Dent J. 2010;21:463-6.

68. Shrivastava S, Tijare M, Singh S. Fusion/double teeth. JIAOMR. 2011;23:468-70.

69. Stewart DJ. Dilacerate unerupted maxillary central incisors. Br Dent J. 1978;145:229-33.

70. Strecha J, Jurkovic R, Siebert T. Fusion of the 2nd maxillary molar with the impacted 3rd molar.

Bratisl Lek Listy. 2012;113:569-71.

71. Tannenbaum KA, Alling EE. Anomalous tooth development: case report of gemination and twinning. Oral Surg Oral Med Oral Pathol.

1963;16:883-8.

72. Thesleff I, Keranen S, Jernvall J. Enamel knots as signaling centers linking tooth morphogenesis and odontoblast differentiation. Adv Dent Res. 2001;15:14-8.

73. Thesleff I. Epithelial–mesenchymal signaling regulating tooth morphogenesis. J Cell Sci. 2003;116:1647-8.

74. Tiecke RW. Pathologic physiology of oral disease. St Louis: Mosby; 1959.

75. Tomes J. A course of lectures on dental physiology and surgery (lectures I-XV). London; 1846-1848.

76. Topouzelis N, Tsaousoglou P, Pisoka V, Zouloumis L. Dilaceration of maxillary central incisor: a literature review. Dental Traumatology.

2010;26:427-33.

77. Vishwanathan S, Nagaraj V, Adimoulame S, Kumar S, Khemaria G. Dens evaginatus in proximal surface of mandibular premolar: A rare presentation.

Case Reports in Dentistry. 2012;1-3.

78. Von Gool AV. Injury to the permanent tooth germ after trauma to the deciduous predecessor.

Oral Surg Oral Med Oral Pathol. 1973;35:2-12.

79. Witkop CJ Jr. Manifestations of genetic diseases s in human pulp. Oral Surg. 1971;32:278-83.

80. Witkop CJ. Clinical aspects of dental anomalies.

Int Dent J. 1976;26:378-90.

81. Yip WK. The prevalence of evaginatus dens. Oral Surg Oral Med Oral Pathol. 1974 Jul;38(1):80-7.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):79-87

Literature Review Article

Indications and restorative techniques for glass ionomer cement Fabio Antonio Piola Rizzante1 Rafael Schlögel Cunali2 Juliana Fraga Soares Bombonatti1 Gisele Maria Correr1 Carla Castiglia Gonzaga2 Adilson Yoshio Furuse1 Corresponding author: Adilson Yoshio Furuse Departamento de Dentística, Endodontia e Materiais Odontológicos Faculdade de Odontologia de Bauru, Universidade de São Paulo E-mail: furuse@usp.br 1 2

Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry – Bauru – SP – Brazil.

Graduate Program in Dentistry, Positivo University – Curitiba – PR – Brazil.

Received for publication: October 20, 2014. Accepted for publication: November 24, 2014.

Keywords: glass ionomer cements; biocompatible materials; dental restoration, permanent.

Abstract Introduction: Due to its chemical, mechanical and biological properties, the glass ionomer cements (GIC) consist in one of the most versatile direct restorative materials, with many potential clinical indications, especially in the context of minimally invasive dentistry. Nevertheless, they have some limitations and require the knowledge of their characteristics and procedures of application in order to achieve their maximum potential. Objective: To demonstrate through literature review the main characteristics, indications, limitations and future perspectives for the use of GIC. Literature review: The database, such as Pubmed and Lilacs were used.

Additionally, books were also evaluated and included. Conclusion: The GIC is in constant evolution and is one of the materials that are best suited in the context of preventive and conservative dentistry.

It has satisfactory properties and versatility. On the other hand, presents inferior properties when compared to other direct restorative materials, requiring caution during its handling.

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Introduction Glass ionomer cements (GICs), also known as glass polyalkenoic cement, has a fundamental role in current Dentistry. This is not only because of the social and preventive aspect of this material when one considers dental caries and concepts based on scientific evidence and minimally invasive dentistry, but also its excellent physical-chemical-mechanical properties, such as fluoride release, adhesion to tooth structure, biocompatibility and coefficient of thermal expansion similar to that of dentin [40, 45]. Moreover, unlike other aesthetic adhesive materials, such as composite resins, adhesion to dental structures of GIC is less sensitive to technique and its quality increases with time [10].

Despite its good properties, constant changes, and improvements, so that GIC restorations show good clinical success, it is important to know its characteristics and proper technique of use. Thus, this paper aims to demonstrate, through literature review, the main characteristics, indications, limitations, and future aspects for the use of this material.

Literature review and discussion Development and evolutions Glass ionomer cements are available since the early 1970s [56] and are derived from silicate and zinc polycarboxylate cements. The polycarboxylate cements were the first materials to provide adhesion to tooth structures, mainly produced by the polyacrylic acid to ensure their biocompatibility, because it is a weak and high molecular weight acid, which does not diffuse through the dentinal tubules. Based on this finding, the polycarboxylate cements gained quickly popularity as cementing agents, but could not be used as restorative materials because of the high solubility of unsatisfactory mechanical properties and unacceptable aesthetics caused by residual zinc oxide. Silicate cements, in turn, appeared on the market in the first decade of the twentieth century and were the first esthetic restorative materials, having anticariogenic properties due to the fluoride release and good dimensional stability, but had numerous disadvantages, including high disintegration and porosity in the oral environment, low color stability and the toxic action on the pulp [42]{Parula, 1975 #142}. Glass ionomer cements then came from the replacement of the zinc oxide by an ionizable reactive glass. This reactive glass is similar to

that existing in the silicate cements. Thus, a more durable, less soluble, and more translucent material was developed [33], with chemical bonding to the dental substrate by the bonding of calcium ions to carboxylic radicals existing in the enamel, dentin and cementum. It is noteworthy that in addition to adhesion to dental structures, GIC also bonds to many metals such as stainless steel, tin or Platinum covered by tin oxide and gold; but it does not adhere to porcelain, pure platinum, or pure gold [33, 36, 45].

Based on these initial studies, it was launched in the European market in the mid-1970s, the first GIC, produced by Dentsply, called ASPA (aluminum silicate and polyacrylate), with unsatisfactory properties such as reduced working time and longer setting time [40, 41].

The GICs are composed of powder and liquid and consist of polymeric matrices with ionic crosslinking around reinforcing glass particles [45]. The powder is composed of three basic components: silica (SiO2), alumina (Al2O3) and calcium fluoride (CaF2). The liquid is an aqueous solution of polyalkenoic acids with the addition of setting accelerators [39]. The setting reaction is acidbase type and starts from the mixture of powder and liquid to form a hydrogel salt, which acts as a binding matrix and unreacted glass particles acting as filler particles [31].

Since its development, the GICs have been constantly improved. During the 1970s, several studies have analyzed and modified the original formula, resulting in improvements in the material, which is now indicated as an excellent alternative for various procedures in practice, since the first formulations presented problems as short clinical time, unsatisfactory aesthetic, reduced working time, sensitivity to moisture variations (syneresis and imbibition), low mechanical strength and longer setting time. To enhance the slow setting reaction of ASPA, in 1976, low molecular weight chelating (tartaric acid) was added to the liquid, which accelerated the setting reaction and facilitated the incorporation of glass powder ions, resulting in ASPA II [9].

Another problem is the initial rapid gelation of liquid because of the formation of internal chains between the hydrogen ions, so the itaconic acid was incorporated into the liquid 1977 with ASPA IV [39].

The first major change in its composition happened during the 1980s, when metal dust pa rt icles were i ncorporated, seek i ng better mechanical properties and radiopacity (so-called Cermet GIC) [35, 50].

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Another important development of the GIC occurred in the late 1980s, when the resin-modified glass ionomer cements appeared (RMGIC) [3]. This development has brought many advantages, such as control of working time, ease of handling, fast setting time, less sensitive to syneresis and imbibition and the opportunity immediately finishing procedure [40]. RMGICs have shown stable adhesion to dentin over the months. It is believed that this stability is related to both the chemical bonding mechanism to hydrox yapatite regard to micromechanical retention [52]. Franco et al. [17] and Fagundes et al. [13], in clinical trials with follow-up of 5 and 7 years, respectively, observed that the evaluated RMGIC presented a clinical performance higher than that of the composite resin. RMGICs tend to be employed because of the longest working time, improved physical properties and aesthetic qualities, and because they are more resistant to dehydration and cracks during setting than the conventional versions, chemically activated.

More re cent ly, w it h t he advent of A R T (atraumatic restorative technique), there was the need to improve the physical properties of these materials, leading then to high viscosity GICs, with chemical activation. These materials have a greater number of particles with smaller sizes.

Susceptibility to syneresis and imbibition Because of GIC and RMGIC setting reaction, sometimes they are more susceptible to syneresis and imbibition [59]. The syneresis is the loss of water due to evaporation of the liquid and can cause gaps and cracks in the cement surface.

Moreover, contamination with water (imbibition) can cause the dissolution of the matrix formed by cations and anions in the surrounding areas [4].

These characteristics justify the need to protect the material after its insertion into the cavity with insulating materials such as: Vaseline, varnishes, fluid resins [6], or colorless nail polish [54].

GIC mechanical properties Compared to resin composites, GICs have lower compressive strength and diametral tensile strength [40], lower resistance to wear [15, 18] and acid erosion [10, 44], and greater friability [38], making unfeasible their use in areas of high concentration of masticatory forces and aesthetic areas.

Another GIC feature is the low modulus of elasticity of the order of 7.3 GPa, half of the modulus of a micro-hybrid composite (15 to 20 GPa) [4], thereby giving it a unique elastic characteristic

that will define some of its clinical indications, e.g., restoration of cervical lesions, because of the bending stress exerted in the area requiring the use of a material with better elastic properties [28].

The low modulus of elasticity also allows its use as a liner material, since the association of GIC with the resins assists in relieving of the forces resulting from the polymerization shrinkage. In this context, it is reported that the use of a glass ionomer as liner material caused a significant reduction in the cusp deflection compared with composite resin restorations without liner [2]. Sampaio et al. [46] observed that the use of RMGIC as liner resulted in lower crack formation on dentin/adhesive interface after laboratorial aging.

Capacity of fluoride release and storage Among all the properties of GIC, one of the most important is its ability to release and store fluoride [51], which can be extended for 8 years [16].

It is known that fluorides are extremely important in the prevention and treatment of dental caries, having the main function of adsorption on the surface of the tooth in the form of CaF2, protecting the tooth and favoring the remineralization process [32]. Given this ability to release and store fluoride, the GIC becomes an excellent choice of restorative material for the treatment of patients at high risk for caries.

This release occurs mainly in the first 24-48 hours, but decreases and stabilizes over time, although it can occur throughout the life of the clinical restoration, with the possible reintroduction of F - ions [11, 41].

Adhesion to tooth structure GICs present chemical adhesion to tooth structure by means of ion exchange. The carboxylic groups replace the phosphate ions of the substrate to establish ionic bonds with calcium ions derived from partially dissolved apatite crystals [11, 41].

This adhesion mechanism was shown by X-ray electron spectroscopy (XPS) in the study of Yoshida et al. [58].

This reaction is also observed for RMGICs [30], although RMGICs generally require that primers containing HEMA and polyacrylic acid are applied on the surface prior to its insertion. These primers infiltrate and polymerize on dentin forming micromechanical retention, similar to what occurs in the hybrid layer in the composites, and should be light cured [26].

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It is noteworthy that the quality and intensity of GIC adhesion to tooth structure can be affected by factors such as physical strength of the material, the substrate nature, surface contamination and type of treatment and/or cleaning performed on the surface in which the restoration is inserted.

Adhesion is severely hampered by the presence of smear layer, as this reduces the free energy of the dentin surface and therefore their reactivity, and is still able to harbor bacteria. Thus, treatment of the tooth surface with polyacrylic acid is essential [23].

It should be noted that, compared with the resins, ionomer cements have a lower bond strength to the dental tissue [10, 34, 45]. However, it is believed that this adhesion is reliable and resistant to disintegration [10]; Furthermore, the results obtained in microtensile tests should be evaluated with caution, because often cohesive failures caused by the material properties do not represent bond strength of the material, but the low cohesive strength of the restorative material, since GIC cohesive fractures were observed in transmission electron and scanning microscopy [57].

Biocompatibility Ionomer cements have low pulp response compared to that produced by the zinc oxide and eugenol cements [53], similar to the response generated by zinc polycarboxylate cements [43].

This biocompatibility occurs because the polyacrylic acid is weak, with macromolecules of high molecular weight, prone to join the calcium of the tooth, making it difficult to move inside the dentinal tubules. Generally, they are less irritating to the pulp tissues when compared to resinous adhesives. However, in deep and very deep cavities, it is recommended the use of a liner with calcium hydroxide cement to ensure that the acid portion of the ionomer (although having low penetrability and being quickly quenched) can not cause any harm [8].

GIC biocompatibility occur not only for pulp tissues, but also for periodontal tissues because GIC is capable of reducing subgingival biofilm compared with resin composite restorations, not irritating the tissues if the biological principles are followed [47-49].

Coefficient of linear thermal expansion GIC present a linea r t herma l ex pa nsion coefficient very close to that of the dental structures and it is suitable as support for undermined enamel

(artificial dentin), without compromising the final bond strength of the restoration. This feature, combined with the chemical bonding capacity with the dental structures, clinically results in a reduced chance of marginal leakage. Note that this property is reduced in RMGIC, with values closer to those presented by the amalgam and composite resins [11, 40].

Classification, indications, limitations, and contraindications Given GIC properties and characteristics, these materials can be classified according to their clinical indication and composition [39].

Concerning to clinical indication Type I: Ionomers indicated for the cementation of inlays, crowns, fixed partial dentures, orthodontic appliances, and endodontic filling. They are fluid materials, also identified as Type I, CEM, C or Luting.

Type II: Ionomers indicated for restorations, presenting particles lager than those of Type I, also identified as R or FIL. Type III: Ionomers indicated for lining, sealing of pits and fissures, also known as Bond and Lining or F. Concerning to composition Conventional GIC: Ionomers with conventional acid-base reaction, displayed as powder and liquid inside different flasks or encapsulated. The glass components and the fluoride are inside the powder and the acids components inside the liquid.

In anhydrous cements, the liquid acid component was freeze-dried (dehydrated) and incorporated into the powder. The liquid is usually distilled water or in an aqueous solution of tartaric acid, which accelerate the setting reaction. These cements have emerged in an attempt to better control the proportioning of powder and liquid and solve the problem of instability of polyacrylic acid, which is very volatile.

Metal reinforced GICs: The liquid is similar to that of the conventional ionomers, while the powder consists of a mixture of conventional powder with amalgam alloy particles or silver particles sintered with the glass. These cements have arisen with the expectation of improving GIC mechanical properties, and although the mechanical properties have been reported to be superior to conventional cements, these do not seem to be different when compared to

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modern cements. The inclusion of metallic particles brought damage to materials in relation to fluoride release, adhesion to tooth structure, as well as the aesthetic damage arising from the darkening of the edges of the cavities. Cermet type GIC has been employed in invasive sealing of posterior teeth and some cases of crown reconstruction.

Resin modified GICs (RMGIC): Incorporation of resin components, primarily HEMA and initiators of polymerization, replacing part of the polyalkenoic acid liquid. These materials were introduced to overcome the problems of sensitivity to moisture, and poor initial mechanical properties associated with the conventional cements. In these materials, the original acid-base reaction is supplemented by a secondary polymerization process initiated by exposure to light. Regardless of the type and amount of resinous material present, so that these new materials could be classified as GIC, they must present adequate acid-base reaction to promote hardening, even in the absence of light.

Hig h-v iscosit y GICs: Those employed i n Atraumatic Restorative Treatment (ART) with high powder-liquid ratio and fast setting reaction.

Based on the classification presented, it can be inferred that the GICs are very versatile materials, indicated for preventive procedures (oral environment adequacy and pits and fissures sealing), restoration of areas of lower masticatory load (class I, class II vertical and horizontal slot, class III and class V restorations) [1, 55]; cavity lining; sandwich restoration (open and close); primary tooth restorations; cementation of post and cores, prostheses; and dentin replacement.

Moreover, GICs have a fundamental role in ART [19, 20, 27].

GIC contraindications are: class II restoration involving the marginal ridge; class IV restoration and teeth with great loss of the labial/ buccal enamel; cusp areas; and areas submitted to great masticatory load.

Another GIC limitation is related to aesthetics.

As a restorative material, conventional GICs are not as aesthetic as composite resins, and therefore are not generally recommended for use in areas of significant cosmetic concern. The RMGIC, on the other hand, can be used in some aesthetically demanding areas, since they have better aesthetic qualities [45]. Notwithstanding, according to Navarro et al. [40], GIC optical properties greatly improved, allowing it to be suitably used in restorations, such as Class III. The authors also claim that conventional GICs have greater color stability when compared with those modified by resin.

A fast surface wear loss may occur in some cases, however, si nce t he tech nique is less demanding, the GICs may function in many aspects, more successfully than the composites. Thus, as the surface properties are apparently lower than those of composite resins, ionomer cements have been widely reported as substitutes for sandwich type restorations [10]. An interesting finding is the inhibition of demineralization areas in restorations of dentin margins with GIC lining, in which the open sandwich technique was employed [52].

Whereas the GICs have unsatisfactory properties of resistance to erosion and abrasion, its application in high-risk patients can be compromised if educational measures regarding hygiene and control of sugar intake are not adopted.

Despite the aforementioned limitations, there are reports of significant percentages of success in clinical evaluations of extensive classes I and II cavities in molars restored with ART technique, comparable to the results obtained with the use amalgam [21, 25, 39], but GIC properties still need to be improved s [7].

Restoration techniques Preliminary considerations During the restorative technique, care must be taken to prevent early failure of the material.

Among them, we can cite [39]: 1. Clean and dry the prepared cavity. The dental structure (dentin and enamel), before receiving the glass ionomer cement should be treated with weak acid solutions, such as polyacrylic acid (10 to 25%), in order to improve the adhesive characteristics of the cement by increasing the surface energy and wetting ability of the surface to be restored; 2. Proper powder-liquid ratio; 3. The vial of powder must be shaken before use (especially the anhydrous cement, in order to prevent excessive amounts of glass particles or lyophilized acid be mixed with the liquid); 4. The liquid bottle should be positioned vertically and at a distance from the glass plate to allow a free drop output; 5. Mixing time should follow the manufacturer1s instructions; 6. The material to be inserted should present a wet brightness; 7. Caution should be taken during the material insertion to avoid bubbles inside the restoration.

This can be prevented by using Centrix syringe; 8. Prevent the wet contamination; 9. Press the material with a matrix for 1 min

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(chemically activated) or during light-curing (photo activated); 10. During the initial removal of the excesses, use the scalpel blade from the restoration towards the tooth structure; 11. The finishing procedure should be performed at the next appointment; 12. Apply the superficial protection immediately after the restoration. GICs are highly sensitive to water gain and loss. Aiming to protect these cements, one can use varnishes provided with the materials, fluid resins, or colorless nail polish; 13. Finishing and polishing procedures should be executed with lubricated instruments to avoid overheating of the restoration, maintaining the moisture of the restorative material.

In addition to these aspects, other care should be emphasized to obtain satisfactory results.

• Caution with the powder and liquid The f lasks must be tightly closed to avoid the gain or loss of water, since the glass ionomer cements are essentially water. The liquid must not be stored in the refrigerator because it loses its original properties. The powder and mixing pad or plate can be kept in a refrigerator in order to increase the working time [39].

• Caution with the encapsulated cements Using the capsule as fast as possible after the breaking of the sheath that protects the environment.

Press the clip that lines the fluid reservoir for at least 2 seconds, which will ensure the passage of all the liquid into the capsule. Use mixer device supplied by the manufacturer or a device that enables 4,000 rpm [39].

Conclusion On this basis of this review, it is noted that the CIV are highly versatile materials and with great clinical potential. Based on the idea of improving the properties of these materials, making them even more effective, or enabling its use as biomaterials [24], some authors have proposed changes in its composition whether such changes can be further perspectives of the material. Among the proposed changes can be highlighted: the modifications by incorporating medications (e.g. chlorhexidine), aiming at the improvement in a ntimicrobia l properties and prevention of secondary caries [12]; association with bioactive glass, aiming at improving the properties of remineralization and antimicrobial activity, making them even better for

restorations in high-risk patients [29]; and insertion of polymers and nanoparticles in GIC matrix [14, 22] to improve the mechanical properties.

Thus, GICs are not only bioactive, but have characteristics of an intelligent material [10]. These materials are considered bioactive because they release fluoride and, as mentioned, are subject to changes in their formulations. They are considered intelligent, because that fluoride release to the oral environment is proportional to the acidity of the medium [10]. It is known that the fluoride release by ionomers occurs in greater quantities during the first 24 hours after its insertion into the cavity and, after this initial period, the release occurs in small amounts. It is interesting to note that even modified ionomer resin, have a clearance behavior when exposed to fluoride [37].

The biocompatibility of traditional glass ionomer cements has been a clinical concern. Upon initial mixing, there is a potential for causing sensitivity and produce pulp irritation. As the setting reaction proceeds, the pH increases from about 1 in early times to a range of 4 to 5. As the setting reaction nears completion, the final pH reaches 6.7 to 7. Once the acid groups are bound to polymer molecules that have limited diffusivity, any potential effects to the pulp from initial pH are limited to areas immediately adjacent to the material. If the amount of residual dentin at the nearest wall of the pulp chamber is less than 0.5 mm, it may be necessary to protect the dentin surfaces of the direct contact with GIC using a calcium hydroxide liner [45].

Although GICs present a less sensitive technique t ha n t hat of resin composites, good results can only be obtained if GIC and the RMGIC are employed in accordance with appropriate clinical protocols, respecting the manufacturer's instructions and always carefully considering the indications, limitations and contraindications of the materials.

Since the principles advocated by Black [5], in 1908, the development of dental materials that can assist in the conservation of tooth structure has aroused. Thus, it is possible to start preventive and conservative dentistry. GIC is one of the materials that best fit the context of preventive and conservative dentistry and, as discussed in this review, has satisfactory properties and great versatility. On the other hand, it has some inferior properties, requiring some caution during handling and restoration. It is noteworthy that, despite their excellent properties, GIC is not the material of choice for all procedures and dental professionals should know their composition and properties,

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to make a correct diagnosis of oral and systemic conditions of the patient, taking into account their needs and anxieties in order to ensure proper application, thereby reaching the clinical success of the restoration procedure.

References 1. Abdalla AI, Garcia-Godoy F. Bond strengths of resin-modified glass ionomers and polyacidmodified resin composites to dentin. Am J Dent.

1997 Dec;10(6):291-4.

2. Alomari QD, Reinhardt JW, Boyer DB. Effect of liners on cusp deflection and gap formation in composite restorations. Oper Dent. 2001 JulAug;26(4):406-11.

3. Antonucci JM, McKinney JE, Stansbury JW. Resin-modified glass-ionomer dental cements field of the invention. US Patent Application. 1988.

4. Anusavice KJ, Shen C, Rawls HR. Philips’ Science of dental materials. 12. ed. St Louis: Saunders; 2013. p. 307-39.

5. Black GV. A work on operative dentistry: the technical procedures in filling teeth. Chicago: Medico-Dental; 1908.

6. Bonifacio CC, Werner A, Kleverlaan CJ. Coating glass-ionomer cements with a nanofilled resin. Acta Odontol Scand. 2012 Dec;70(6):471-7.

7. Burke FJ. Dental materials – what goes where?

The current status of glass ionomer as a material for loadbearing restorations in posterior teeth.

Dent Update. 2013 Dec;40(10):840-4.

8. Caviedes-Bucheli J, Ariza-Garcia G, Camelo P, Mejia M, Ojeda K, Azuero-Holguin MM et al. The effect of glass ionomer and adhesive cements on substance P expression in human dental pulp.

Med Oral Patol Oral Cir Bucal. 2013 Nov;18(6): e896-901.

9. Crisp S, Wilson AD. Reactions in glass ionomer cements: V. Effect of incorporating tartaric acid in the cement liquid. J Dent Res. 1976 NovDec;55(6):1023-31.

10. Davidson CL. Advances in glass-ionomer cements. J Appl Oral Sci. 2006;14(Suppl):3-9.

11. Davidson CL, Mjör IA. Advances in glass ionomer cements. Carol Stream: Quintessence; 1999.

12. De Castilho AR, Duque C, Negrini T de C, Sacono NT, De Paula AB, De Souza Costa CA et al.

In vitro and in vivo investigation of the biological and mechanical behaviour of resin-modified glassionomer cement containing chlorhexidine. J Dent.

2013 Feb;41(2):155-63.

13. Fagundes T, Barata T, Bresciani E, Santiago S, Franco E, Lauris J et al. Seven-year clinical performance of resin composite versus resin-modified glass ionomer restorations in noncarious cervical lesions. Oper Dent. 2014 NovDec;39(6):578-87.

14. Fareed MA, Stamboulis A. Effect of nanoclay dispersion on the properties of a commercial glass ionomer cement. Int J Biomater. 2014;2014:10.

DOI685389.

15. Forss H, Seppa L, Lappalainen R. In vitro abrasion resistance and hardness of glass-ionomer cements. Dent Mater. 1991 Jan;7(1):36-9.

16. Forsten L. Fluoride release and uptake by glassionomers and related materials and its clinical effect. Biomaterials. 1998 Mar;19(6):503-8.

17. Franco EB, Benetti AR, Ishikiriama SK, Santiago SL, Lauris JR, Jorge MF et al. 5-year clinical performance of resin composite versus resin modified glass ionomer restorative system in non-carious cervical lesions. Oper Dent. 2006 Jul-Aug;31(4):403-8.

18. Freitas MFA, Imai LJ, Freitas CA, Bianchi EC, Almeida CT, Martins Filho IE. Abrasive wear of two glass ionomer cements after simulated toothbrushing. RSBO. 2011;8:287-93.

19. Frencken JE, Holmgren CJ. Caries management through the atraumatic restorative treatment (ART) approach and glass-ionomers: update 2013. Braz Oral Res. 2014 Jan-Feb;28(1):5-8.

20. Frencken JE, Leal SC, Navarro MF. Twentyfive-year atraumatic restorative treatment (ART) approach: a comprehensive overview. Clin Oral Investig. 2012 Oct;16(5):1337-46.

21. Frencken JE, Van’t Hof MA, Van Amerongen WE, Holmgren CJ. Effectiveness of single-surface ART restorations in the permanent dentition: a meta-analysis. J Dent Res. 2004 Feb;83(2): 120-3.

22. Garcia-Contreras R, Scougall-Vilchis RJ, Contreras-Bulnes R, Kanda Y, Nakajima H, Sakagami H. Effects of TiO2 nano glass ionomer cements against normal and cancer oral cells. In Vivo. 2014 Sep-Oct;28(5):895-907.

86 – RSBO. 2015 Jan-Mar;12(1):79-87 Rizzante et al. – Indications and restorative techniques for glass ionomer cement

23. Hajizadeh H, Ghavamnasiri M, Namazikhah MS, Majidinia S, Bagheri M. Effect of different conditioning protocols on the adhesion of a glass ionomer cement to dentin. J Contemp Dent Pract.

2009;10(4):9-16.

36. McLean JW, Wilson AD. The clinical development of the glass-ionomer cements. i. Formulations and properties. Aust Dent J. 1977 Feb;22(1):31-6.

24. Hatton PV, Hurrell-Gillingham K, Brook IM. Biocompatibility of glass-ionomer bone cements.

J Dent. 2006 Sep;34(8):598-601.

37. Mitra SB, Oxman JD, Falsafi A, Ton TT. Fluoride release and recharge behavior of a nanofilled resin-modified glass ionomer compared with that of other fluoride releasing materials. Am J Dent. 2011 Dec;24(6):372-8.

25. Hilgert LA, de Amorim RG, Leal SC, Mulder J, Creugers NH, Frencken JE. Is high-viscosity glass-ionomer-cement a successor to amalgam for treating primary molars? Dent Mater. 2014 Oct;30(10):1172-8.

38. Mitsuhashi A, Hanaoka K, Teranaka T. Fracture toughness of resin-modified glass ionomer restorative materials: effect of powder/liquid ratio and powder particle size reduction on fracture toughness. Dent Mater. 2003 Dec;19(8):747-57.

26. Hinoura K. Factors influencing dentin bond of a tricured type II glass ionomer. J Dent Res. 1994;73:329 (abstract n. 1815).

39. Navarro MFL, Bresciani E, Barata TJE, Fagundes TC. Tratamento restaurador atraumático (ART) e o programa de saúde da família. Biodonto.

2004;2(4):9-111.

27. Holmgren CJ, Roux D, Domejean S. Minimal intervention dentistry: part 5. Atraumatic restorative treatment (ART) – a minimum intervention and minimally invasive approach for the management of dental caries. Br Dent J. 2013 Jan;214(1): 11-8.

28. Ichim IP, Schmidlin PR, Li Q, Kieser JA, Swain MV. Restoration of non-carious cervical lesions Part II. Restorative material selection to minimise fracture. Dent Mater. 2007 Dec;23(12):1562-9.

29. Khoroushi M, Keshani F. A review of glassionomers: from conventional glass-ionomer to bioactive glass-ionomer. Dent Res J. 2013 Jul;10(4):411-20.

30. Lin A, McIntyre NS, Davidson RD. Studies on the adhesion of glass-ionomer cements to dentin.

J Dent Res. 1992 Nov;71(11):1836-41.

31. Loguercio AD, Reis A, Navarro MFL. Materiais dentários restauradores diretos – dos fundamentos à aplicação clínica. São Paulo: Santos; 2007. p.

217-51.

32. Magalhaes AC, Levy FM, Rizzante FA, Rios D, Buzalaf MA. Effect of NaF and TiF4 varnish and solution on bovine dentin erosion plus abrasion in vitro. Acta Odontol Scand. 2012 Mar;70(2):160-4.

33. McCabe JF, Walls AWG. Applied dental materials. Oxford: Blackwell; 2008.

34. McLean JW. Dentinal bonding agents versus glass-ionomer cements. Quintessence Int. 1996 Oct;27(10):659-67.

35. McLean JW, Gasser O. Glass-cermet cements.

Quintessence Int. 1985 May;16(5):333-43.

40. Navarro MFL, Barata TJE, Fagundes TC, Henostroza-Quintans N. Estética en odontología restauradora. Madrid: Ripano; 2006. p. 265310.

41. Navarro MFL, Pascotto RC. Cimentos de ionômero de vidro – aplicações clínicas em Odontologia. São Paulo: Artes Médicas; 1998.

42. Parula N. Clínica de operatoria dental. 4. ed.

Buenos Aires: ODA; 1975.

43. Plant CG, Shovelton DS, Vlietstra JR, Wartnaby JM. The use of glass ionomer cement in deciduous teeth. Br Dent J. 1977 Oct 18;143(8):271-4.

44. Reddy DS, Kumar RA, Venkatesan SM, Narayan GS, Duraivel D, Indra R. Influence of citric acid on the surface texture of glass ionomer restorative materials. J Conserv Dent. 2014 Sep;17(5): 436-9.

45. Roberson TM, Heymann HO, Swift Jr EJ. Sturdevant’s art & science of operative dentistry.

5. ed. St Louis: Mosby; 2006.

46. Sampaio PC, de Almeida Junior AA, Francisconi LF, Casas-Apayco LC, Pereira JC, Wang L et al.

Effect of conventional and resin-modified glassionomer liner on dentin adhesive interface of Class I cavity walls after thermocycling. Oper Dent. 2011 Jul-Aug;36(4):403-12.

47. Santamaria MP, Suaid FF, Carvalho MD, Nociti Jr FH, Casati MZ, Sallum AW et al. Healing patterns after subgingival placement of a resinmodified glass-ionomer restoration: a histometric study in dogs. Int J Periodontics Restorative Dent.

2013 Sep-Oct;33(5):679-87.

87 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):79-87 Rizzante et al. â&#x20AC;&#x201C; Indications and restorative techniques for glass ionomer cement

48. Santos VR, Lucchesi JA, Cortelli SC, Amaral CM, Feres M, Duarte PM. Effects of glass ionomer and microfilled composite subgingival restorations on periodontal tissue and subgingival biofilm: a 6-month evaluation. J Periodontol. 2007 Aug;78(8):1522-8.

49. Sidhu SK. Glass-ionomer cement restorative materials: a sticky subject? Aust Dent J. 2011 Jun;56(Suppl1):23-30.

50. Simmons JJ. The miracle mixture. Glass ionomer and alloy powder. Tex Dent J. 1983 Oct;100(10):6-12.

51. Swartz ML, Phillips RW, Clark HE. Long-term F release from glass ionomer cements. J Dent Res. 1984 Feb;63(2):158-60.

54. Valera VC, Navarro MF, Taga EM, Pascotto RC. Effect of nail varnishes and petroleum jelly combinations on glass ionomer dye uptake. Am J Dent. 1997 Oct;10(5):251-3.

55. Van Dijken JW. 3-year clinical evaluation of a compomer, a resin-modified glass ionomer and a resin composite in class III restorations. Am J Dent. 1996 Oct;9(5):195-8.

56. Wilson AD, Kent BE. The glass-ionomer cement: a new translucent dental filling material.

J Appl Chem Biotechnol. 1971;21:313.

57. Yip HK, Tay FR, Ngo HC, Smales RJ, Pashley DH. Bonding of contemporary glass ionomer cements to dentin. Dent Mater. 2001 Sep;17(5):456-70.

52. Tantbirojn D, Rusin RP, Bui HT, Mitra SB. Inhibition of dentin demineralization adjacent to a glass-ionomer/composite sandwich restoration.

Quintessence Int. 2009 Apr;40(4):287-94.

58. Yoshida Y, Van Meerbeek B, Nakayama Y, Snauwaert J, Hellemans L, Lambrechts P et al.

Evidence of chemical bonding at biomaterial-hard tissue interfaces. J Dent Res. 2000 Feb;79(2):70914.

53. Tobias RS, Browne RM, Plant CG, Ingram DV. Pulpal response to a glass ionomer cement. Br Dent J. 1978 Jun;144(11):345-50.

59. Zankuli MA, Devlin H, Silikas N. Water sorption and solubility of core build-up materials. Dent Mater. 2014 Sep 6.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):88-93

Literature Review Article

Application of BMP-2 for bone graft in Dentistry Lídia Audrey Rocha Valadas Marques1 Edvan Alves da Costa Júnior1 Mara Assef Leitão Lotif1 Edilson Martins Rodrigues Neto2 Francisco Filipe Carvalho da Silva1 Carlos Ricardo de Queiroz Martiniano1 Corresponding author: Carlos Ricardo de Queiroz Martiniano Rua Carolina Sucupira, n. 1.985, ap. 402 – Cocó CEP 60140-120 – Fortaleza – CE – Brasil E-mail: cricardo.martiniano@gmail.com Department of Dental Clinics, School of Pharmacy, Dentistry, and Nurse, Federal University of Ceará – Fortaleza – CE – Brazil.

2 Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceará – Fortaleza – CE – Brazil.

1

Received for publication: January 21, 2014. Accepted for publication: November 24, 2014.

Abstract Keywords: dental implants; maxillary sinus; biocompatible materials.

Introduction: The global increase life expectancy and the resulting tooth loss has required searching for new rehabilitation alternatives in Dentistry. Biomaterials can be defined as any material that acts replacing a lost bone defect and its function. In Dentistry, many studies have aimed to improve bone regeneration through the use of BMPs for bone replacement. Objective: To review the literature on the use and clinical viability of human morphogenetic protein for the jaws reconstruction. Material and methods: The following databases were searched: Pubmed, Bireme, Lilacs, and Scielo and 30 articles published between 1965 and 2013 were found using the following descriptors: “dental implants”, “maxillary sinus”, and “biocompatible materials”. Results: Several studies demonstrate the biological advantages of rhBMP-2 on bone regeneration of the jaws.

In recent years, morphogenetic protein has presented a large clinical use. Conclusion: Despite being a high-cost biomaterial, rhBMP-2 is a viable and very effective alternative for reconstruction of defects of the face.

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Introduction The increased expectation of worldwide life and the consequent tooth loss have required more and more of Dentistry the search for viable alternatives to oral rehabilitation [20].

After the scientific evidence of osseointegration in the ending of the 1970s, which made viable Implantology, increased the interest of researchers in search by new natural or synthetic substances that could replace tissues bone lost [9]. In Dentistry autogenous bone is the most useful tissue used in pre-prosthetic surgery and rehabilitation treatment of bone defects, thereby contributing to the function and aesthetics [8].

Biomaterials can be defined as “any material, natural or synthetic, that acts in tissues/organs in order to replace the bone defect lost and s function” [13]. The biomaterials may be considered autogenous when the bone is taken from the individual to be treated; halogens, when the gathered from another individual of the same species, and heterogeneous, when taken from other species [6].

The huma n bone morphogenet ic protein (rhBMP) developed by genetic engineering, was isolated by Urist, in 1965, and it is considered a substance capable of inducing differentiation of mesenchymal stem cells into osteoblasts, the cells that are responsible for the synthesis of bone matrix. Research given to BMPs the capacity of fracture repair, osteogenic, osteoinductive, and osteoconductive potential of the graft [22].

In Dentistry, many studies have aimed to improve bone regeneration through the use of BMPs for bone replacement. Because of the osteoinductive capacity, BMPs have various application possibilities in the Dentistry, raising great interests in various specialties, especially in the Implantology, assisting in osseointegration [30].

The aim of this study was to conduct a literature review on the use and clinical viability of human bone morphogenetic protein (rhBMP-2) for grafting bone in Dentistry.

Literature Review Grafts in Implantology The success of rehabilitation with dental implants is directly related to the amount of bone tissue of the patient. As the resorption is something common mainly in older patients, it is increasingly common the application of techniques for maxillary sinus augmentation by using grafts. In addition,

tumors, congenital deformities, trauma, among others, may require the need for reconstruction of jaws [14, 25].

The autogenous graft type, considered the gold standard, is best used for the rehabilitation of the jaws, because of their osteogenic, osteoconductive, and osteoinductive properties. However, autogenous grafts require a second surgical site, and the bone is removed normally from the mandibular ramus, chin, skullcap, iliac, or tibia. The need for a second surgical site makes the surgical process more complex with side effects to the patient [27].

The homogenous and heterogeneous grafts lack of living cells, since pass through a process of purification, but may show osteoconductive or osteoinductive features. The great advantage of these two types of graft is that they do not need a second surgical site, which makes the reconstructive procedure faster, safer, and less complex [8].

The biomaterial for optimal bone grafting should be osteogenic, osteoinductive, osteoconductive, be biologically inert, and have fast revascularization activity [8].

History and classification of rhBMPs Urist [28] conducted an innovative experiment and with very promising results, in which muscle tissue was implanted on rabbit leg in demineralized bone matrix. After 3 weeks, it was observed the formation of ectopic bone. Thus, it was concluded that the bone matrix contained some important factor capable of performing a self-induction. This factor was called bone morphogenetic protein (BMP). The initial advancement led to the study of several researchers seeking to isolate and clone the inductive entity. Actually it is known that it is not only one but several growth factors.

Currently, despite the knowledge of the capacity, by manipulation of the medium, of differentiating in osteoblasts, the mechanisms that govern these actions are not fully elucidated [21]. The molecular bases of bone morphogen protein, which mostly belong to the superfamily of transformation growth factor β (TGF-β) accounts for these mechanisms [15]. It is known that this set of proteins is made up of 12 different types of inducing molecules, each of which develops a specific function, and may also perform joint actions by interacting among each other. Thus, they are classified as: BMP 1, 2, and 3 (osteogenin); 4 to 7 (Osteogenic Protein-1); 8 (osteogenic protein-2 ca); 9-12 in isolated group [23].

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Bone morphogenetic proteins are obtained by genetic engineering techniques. They are produced by genetic recombination in Escherichia coli and sold as lyophilized powder in sterile vial, ready for use.

This lyophilized powder associated with a vehicle benefits the bone-implant interface, accelerating osseointegration [12, 19].

The rhBMP commercially available and approved

by FDA in the United States currently are: rhBMP2 Infuse (Medtronic Sofamor Danek, Memphis, Tennessee) and OP1 (Stryker Biotech, Hopkinton, MA). Other BMP products are currently being evaluated for commercial use include BMP-X (Sulzer Biologics, Wheat Ridge, Colorado), BMP -9, and combinations of BMP animal and human [1].

Hu et al. [11] stated that BMP-9 is one of the most potent forms between 12 rhBMP types in the induction of osteogenic differentiation of mesenchymal progenitor cells, both in vitro and in vivo, through the regulation of several major targets during differentiation of the rhBMP-9 osteoblasts induced.

placed on the site. In addition, carrier agents are needed to make the diffusion agents among cells to facilitate osteoinduction [14].

The optimum carrier substrate should provide the following characteristics: relative insolubility under physiological conditions; to be biodegradable; to protect the tissue against proteolytic activities; to function as substrate for cell adhesion and proliferation; to be inert immunologically; to obtain the slow and controlled release of rhBMP through controlled biological degradation; and to have mechanic stability to unite bone defects [10].

Among the biomaterials tested as carriers, various extracellular matrix components may be used alone or in combination, for example: collagen, fibronectin, glycosaminoglycans, calcium hydroxide, and calcium phosphate [10].

The spongy bone graft has been considered an ideal carrier. It acts as a scaffold promoting early vascularization and osteoinduction, and provides osteogenic cells, is biocompatible, and has the ability to adapt to bone failures [14].

A rhBMP-2 Infuse® is marketed in package containing all the components needed to prepare the bone inducing component Infuse®: rhBMP-2 lyophilized powder to be reconstituted, sterile water, absorbable collagen sponge, syringe with needles, and preparation instructions. The number of each item may vary depending on the size to be used. The rhBMP-2 is provided as a lyophilized powder in vials with 4.2 mg or 12 mg of protein.

After proper reconstitution, both sets result in the same formulation and concentration (1.5 mg/cc) of rhBMP-2 [5].

According to the manufacturer, the Infuse® bone graft should be prepared at surgery time, always 30 minutes before the application of the material in the surgical site. With the aid of syringe and needle, the sterile water must be removed from the bottle and inject in the vial containing rhBMP2, then mix slowly without stirring and leave at least 15 minutes at rest for complete dissolution.

The original packaging IS opened and puts the absorbable collagen sponge in sterile field. With the aid of the second syringe, the reconstituted bone graft is removed from ampule and is applied uniformly in the sponges. The moist sponges should rest for at least 15 minutes (time for incorporation of the protein to the sponge) and must be used within two hours (for avoiding the drying of the sponge) [5].

Application Form

Advantages of rhBMP-2

A bone graft BMPs kit is used for the repair and bone growth, and after handling BMP is directly

The regenerative activity and bone induction of rhBMP-2 has been extensively studied by researchers

Mechanisms of rhBMPs The rhBMPs may be defined as signaling glycoproteins, and members of the superfamily of growth factor β (TGF-β), capable of recruiting osteoprogenitor cells to sites of bone formation, and are macromolecules of essential role in the repair process and bone growth. The osteoinductive action of autogenous and demineralized homogenous bone matrix graft may also be attributed to that protein.

Nakashima [15] found that these proteins stimulated mitosis of mesenchymal stem cells because they have the ability to turn on specific receptors, as serine/threoninacinase and induce differentiation of precursor cells of osteodentin tissue, which are osteodentinocytes. The osteodentin, major component of dental matrix newly formed, seems to have a coadjutant role in the differentiation of osteoblasts, because in its absence, promising results were not obtained [15, 24].

Accordingly, the rhBMPs can be used in the reconstruction of bone tissue, having wellestablished benefit in Dentistry and Orthopedics, since they are able to induce migration, proliferation and differentiation of mesenchymal stem cells into secretory osteoblasts and form bone [7].

Brand and product

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of Genetic Engineering, which its advancement allowed the characterization, cloning and largescale commercial production. Studies evaluating the association of rhBMPs with biomaterials showed to be a viable and effective alternative to make bone regeneration ease [30].

Since the discovery of rhBMP, several studies have demonstrated the biological advantages of rhBMP-2 and significant rehabilitation on bone formation in studies both on rats and humans, which takes about six months [29].

A study evaluated the applicability of rhBMP-2 in a collagen sponge after it had been applied in bone defects. It was observed that after 12 weeks the mean neoformation and bone density in the group that received rhBMP-2 was nearly 4 times greater than that of the control group [18].

In recent years, the morphogenetic protein has been highly successful for the reconstruction of the jaw defects and large defects of the face. The great advantage compared to autogenous bone is that it eliminates the need for a second surgical site, which considerably increased the surgery time, and bone removal from another area as the iliac, tibial or skullcap [2, 14].

Clinical trials that studied the effect of BMP-2 in collagen sponges regarding to bone deposition detected a significant growth and bone formation in the surgery of maxillary sinus lifting. In addition, other studies show that rhBMP-2 has been successful in complex treatments of the face, as congenital jaw defects in alveolar atrophy, and maxillary fissures [18].

The association of rhBMP-2 with homogenous graft also showed favorable clinical outcomes in peri-implant bone resorption [18].

Disadvantages of rhBMP-2 The morphogenet ic protei ns a re readi ly diffusible and soluble in water, so they must be applied with a carrier so that an effective inducing effect is established [10].

The carrier systems for rhBMPs still require research to optimize their formulations. The use of collagen isolated or associated with carrier systems, although widely used, has some disadvantages that must be observed, such as poor mechanical stability, immune response and potential for transmission of viral antigens [10].

When rhBMPs are compared to PRPs (platelet rich plasma), the main disadvantages of the morphogenetic proteins are the high cost and the need to use a carrier agent [12].

Although the studies show good results in the process of the osteoinduction, they do not quantify the value of the speed increase of the process when using rhBMPs [12].

When working with rhBMP, caution should be taken, because it is a very sensitive material regarding to technique, any error in handling can lead to unsatisfactory results. The effectiveness of this material may be affected by factors such as amount, qualitative composition, possible presence of inhibitors, processing and storage. And, for the inductive result, the dose, concentration, and time of action of rhBMPs are influencing factors [26].

The multiple rhBMPs forms already identified demand new studies, which may happen slowly, due to the high costs involved in research with morphogenetic proteins. Such researches are needed to determine the choice for the most appropriate factor for each therapy and also enable the direction of new techniques [10].

The literature presents many advantages in the use of various forms of morphogenetic proteins, but the studies are still few compared to various therapeutic applications of rhBMP, beyond the specialties of Dentistry. This may occur because of the high costs needed to develop research with this material.

Discussion Undoubtedly, the advances in Genetic Engineering have brought new viable and effective alternatives for Dentistry. These included, biomaterials stand out, and researches associated with the use of rhBMPs emerge as another option for new bone formation.

Among the group consisting of the rhBMP proteins, rhBMP-2 showed higher expression in human bone in scientific research [13].

Yonezawa et al. [29] and Padovan et al. [18], in studies with the use of morphogenetic proteins, demonstrated positive results in terms of bone formation and density, implying a significant rehabilitation for critical defects and alveolar bone grafting.

In another study, in which the bone formation was investigated in the maxillary sinus of goats using rhBMP-2 in an absorbable collagen sponge, the osteoinductive capacity of the protein was proven without side effects [13]. The authors also claim that rhBMP-2 really is an alternative for maxillary sinus lifting in humans.

A clinical trial with 160 patients, in which the effectiveness of rhBMP-2 was compared to

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autogenous bone in maxillary sinus lifting and installation of dental implants, concluded that bone formation in height was the same in both groups [16].

The study of Cruz et al. [4] found that progenitor cells derived from human adipose tissue expressed rhBMP-4, endogenous rhBMP-7. On the other hand, the supplementation of progenitor cells derived from adipose tissue with rhBMP-2 did not increase the level of osteogenic markers at the initial phase (activity of alkaline phosphatase), at the intermediate phase (osteonectin and osteocalcin), or final phases (calcium deposition), suggesting that the exogenous addition of rhBMP-2 did not improve the process of osteogenesis in vitro of progenitor cells derived from adipose tissue human.

Oliveira et al. [17] evaluated the healing of tibial defect induced in dogs. Eighteen adult dogs were divided into three groups of six dogs each.

The defects were filled with bone collagen sponge.

In group 1 (G1), a sponge added with 0.9% saline solution was used; in G2, a sponge added with processed autologous mononuclear bone marrow cells was used; a nd in G3, a sponge added with processed autologous mononuclear bone marrow cells and rhBMP-2 was used. Although G2 presented a better result than G1, bone growth in G3 (supplemented with rhBMP-2) showed the best results in the analyses of 15 and 30 days after the start of the experiment. Forty-five days later, 50% of this group of dogs already had complete healing of the bone defect [17].

Despite the excellent results obtained in various researches and clinics using rhBMP-2, little is reported in the literature on the adverse effects and complications that can occur when using this graft material. Carragee et al. [3] criticized the industry to report that it is a product that has no risk, even when several studies suggest the opposite. The same study did a survey on adverse effects using rhBMP-2 in human spinal surgeries and obtained as possible complications: infection, malignancy risk at high doses, morbidity (pain and functional impairment), ectopic bone formation, retrograde ejaculation and urogenital adverse effects.

second surgical site to the patient. Notwithstanding, the high costs of this biomaterial still prevent many individuals to benefit and that researches are developed.

Conclusion

9. Faverani LP, Ferreira GR, Jardim ECG, Okamoto R, Shinohara EH, Assunção WG et al. Implantes osseointegrados: evolução sucesso. Salusvita.

2011;30(1):47-58.

The morphogenetic proteins have major clinical applications; however, research is still necessary to establish proper techniques for the use of rhBMP s for each specific case. In Implantology, rhBMPs emerged as the major substitute to autogenous bone grafting, especially for its osteoinductive characteristics and for dispensing the need of a

References 1. Bagaria V, Prasad V. Bone morphogenic proteins: current state of the field and the road ahead. J Orthopaedics. 2005;2(4):30-3.

2. Balaji SM. Augmentation of residual alveolar bone height with tissue engineering for dental implant placement. Indian Journal of Dental Research. 2014;25(3):410.

3. Carragee EJ, Hurwitz EL, Weiner BK. A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned. Spine J. 2011;11(6):471-91.

4. Cruz ACC, Silva ML, Caon T, Simões CMO. Addition of bone morphogenetic protein type 2 to ascorbate and β-glycerophosphate supplementation did not enhance osteogenic differentiation of human adipose-derived stem cells. J Appl Oral Sci. 2012;20(6):628-35.

5. Dabasons. Infuse® rhBMP-2 indutor ósseo [cited 2013 Nov 11]. Available from: URL:http://www. bmp2.com.br/infuse.php.

6. Dalapicula SS, Vidigal Junior GM, Conz MB, Cardoso ES. Características físico-químicas dos biomateriais utilizados em enxertias ósseas: uma revisão crítica. Implant News. 2006;3(1):487-91.

7. Esposito M, Grusovin MG, Coulthard P, Worthington HV. The efficacy of various bone augmentation procedures for dental implants: a Cochrane systematic review of randomized controlled clinical trials. Int J Oral Maxillofac Implants. 2006;21(5):696-710.

8. Fardin AC, Jardim ECG, Pereira FC, Guskuma MH, Aranega AM, Garcia Junior IR. Bone graft in dentistry: review of literature. Innov Implant J Biomater Esthet. 2010;5(3):48-52.

10. Gonçalves EAL, Guimarães SAC, Garcia RB. Proteínas morfogenéticas ósseas: terapêutica molecular no processo de reparo tecidual. Rev Odontol Univ. 1998;12(3):299-304.

93 – RSBO. 2015 Jan-Mar;12(1):88-93 Marques et al. – Application of BMP-2 for bone graft in Dentistry

11. Hu N, Jiang D, Huang E, Liu X, Li R, Liang X et al. BMP9-regulated angiogenic signaling plays an important role in the osteogenic differentiation of mesenchymal progenitor cells. J Cell Sci. 2013;126(2):532-41.

21. Rutherford RB, Wahle J, Tucker M, Rueger D, Charette M. Induction of reparative dentine formation in monkey by recombinant human osteogenic protein-1. Archs Oral Biol.

1993;38(7):571-6.

12. Loureiro CCS. PRP ou BMPs: qual a melhor opção para enxertia e aceleração de osseointegração nas reabilitações com implantes? Revisão de literatura. Innov Implant J. 2010;5(2):45-50.

22. Santos AA, Miranda CDO, Alves MTS, Faloppa F. The role of bone morphogenetic protein on bone tissue repair. Acta Ortop Bras. 2005;13(4):70-7.

13. Martins JV, Perussi MR, Rossi AC, Freire AR, Prado FB. Biomaterials used in maxillary sinus lifting surgery: clinical approach. Revista Odontológica de Araçatuba. 2010;31(2):22-30.

14. Misch CM. The use of recombinant human bone morphogenetic protein-2 for the repair of extraction socket defects: a technical modification and case series report. Int J Oral Maxillofac Implants. 2010;25(6):1246-52.

15. Nakashima M. Induction of dentine formation on canine amputed pulp by recombinant human bone morphogenetic proteins (BMP) -2 and -4. J Dent Res. 1994;73(9):1515-22.

16. Oliveira EMF, Vitorino NS, Freitas PHL, Wassal T, Napimoga MH. Uso de proteínas recombinantes na reconstrução de maxilares. Rev Gaúcha Odontol.

2011;59(3):491-6.

17. Oliveira GK, Raiser AG, Olsson D, Salbego FZ, Martins DB, Dezengrine R et al. Célulastronco mononucleares autólogas e proteína óssea morfogenética na cicatrização de defeitos tibiais experimentalmente induzidos em cães. Arq Bras Med Vet Zootec. 2010;62(1):72-9.

18. Padovan LEM, Luiz J, Claudino M. Aplicabilidade da rhBPM-2 em procedimentos de enxertia: relato de caso. J ILAPEO. 2013;7(2):20-7.

19. Ramazanoglu M, Lutz R, Ergun C, von Wilmowsky C, Nkenke E, Schlegel KA. The effect of combined delivery of recombinant human bone morphogenetic protein-2 and recombinant human vascular endothelial growth factor 165 from biomimetic calcium-phosphate-coated implants on osseointegration. Clin Oral Implants Res. 2011;22(12):1433-9.

20. Ribeiro DG, Silva MM, Nogueira SS, Arioli Filho JN. A saúde bucal na terceira idade. Salusvita.

2009;28(1):101-11.

23. Six N, Lasfargues JJ, Goldberg M. Differential repair responses in the coronal and radicular areas of the exposed rat molar pulp induced by recombinant human bone morphogenetic protein-7 (Osteogenc Protein-1). Arch Oral Biol.

2002;47(3):177-87.

24. Sommernan M, Hewitt AT, Varner HH, Schiffmann E, Termine J, Reddi AH. Identification of bone matrix-de-rived chemotatic factor. Calcif Tissue Int. 1983;35(1):481-5.

25. Spagnoli DB, Marx RE. Dental implants and the use of rhBMP-2. Dental Clinics of North America.

2011;55(4):883-907.

26. Sykaras N, Opperman LA. Bone morphogenetic proteins (BMPs): how do they function and what can they offer the clinician? J Oral Sci. 2003;45(2):57-73.

27. Toledo Filho JL, Marzola C, Sanchez MPR. Os enxertos ósseos e de biomateriais e os implantes osseointegrados. Rev Bras Cir Implant.

2001;8(30):126-43.

28. Urist MF. Bone: formation by autoinduction.

Science. 1965;150(698):893-9.

29. Yonezawa H, Harada K, Ikebe T, Shinohara M, Enomoto S. Effect of recombinant human bone morphogenetic protein-2 (rhBMP-2) on bone consolidation on distraction osteogenesis: a preliminary study in rabbit mandibles. J Craniomaxillofac Surg. 2006;34(1):270-6.

30. Yoo D, Tovar N, Jimbo R, Marin C, Anchieta RB, Machado LS et al. Increased osseointegration effect of bone morphogenetic protein 2 on dental implants: An in vivo study. J Biomed Mater Res Part A. 2014;102A:1921-7.

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Case Report Article

Mesiodens surgery at deciduous and permanent dentition Mariana Dalledone1 Paulo Afonso Tassi-Junior2 Juliana Feltrin de Souza1 Estela Maris Losso1 Corresponding author: Estela Maris Losso Positivo University Rua Pedro Viriato Parigot de Souza, n. 5.300 – Campo Comprido CEP 81280-330 – Curitiba – PR – Brasil E-mail: lossoem@gmail.com 1 2

Positivo University – Curitiba – PR – Brazil.

DDS.

Received for publication: March 13, 2014. Accepted for publication: July 12, 2014.

Abstract Keywords: supernumerary teeth; cone-bean computed tomography; pediatric dentistry.

Introduction and Objective: To report a rare case of a patient who presented two mesiodens and the treatment performed at two moments. Case report: A 7 year-old male patient reported a supernumerary tooth extracted at age 4. The dental clinical exam revealed giroversion of permanent maxillary right central incisor.

Cone-beam computed tomography (CBTC) revealed a presence of a mesiodens located at the buccal surface mesially to the permanent maxillary left central incisor and also indicated that the mesiodens was located close to the f loor of the nasal cavity. The surgery was performed with a conservative intervention and osteotomy by preserving the adjacent structure. The one-year following-up postoperative x-ray indicated new bone deposition and a more favorable eruption position of the right permanent maxillary lateral incisor.

Conclusion: It can be concluded that an early diagnosis by CBTC allowed an adequate treatment planning, which avoid the formation of cysts and a prolonged retention of permanent tooth.

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Introduction

Case report

A n alteration in the eruption of teeth or non-eruption is a frequent event in a pediatric pat ient, a ffect ing ma inly t he upper incisors group and representing an unpleasant aesthetical and functional factor. The phenomenon may be determined commonly by the presence of supernumerary tooth [2, 4].

Supernumerary tooth is an anomaly in number of tooth, where one or more teeth develop beyond the normal series [2]. Mesiodens can be defined as supernumerary teeth, located in between two upper central incisors, identified as having a coneshaped crown and short root. Most of mesiodens are located at the palatal area of permanent incisors [5]. This prevalence is low, from 0.15% to 1.9%, predominantly in males, with ratio of 2:1 [5, 6, 8].

Concerning to the etiology, the most accepted theory is the hyperactivity of the dental lamina [2].

Cone-shaped mesiodens occurs in isolated cases, and the incidence of multiples is a rare fact. If inverted positioned, it might be close to the floor of the nasal cavity. Supernumerary teeth in other locations may also cause failure of eruption of adjacent teeth, commonly, retention of the incisors.

The problem is usually noticed with the eruption of the maxillary lateral incisors together with the failure of eruption of one or both central incisors.

In these cases, the removal of the supernumerary tooth is recommended [7].

With regard to pediatric dentistry practice, the dental procedures are related to pain, anesthesia, a nd pa rents’ a n x iet y that may inf luence the children´s behavior, making the dental experience negative as well. In this field, the role of the pediatric dentist is to conduct the child using adequate care methods, minimizing the procedure duration, promoting conservative procedures, according to the age and psychology pattern of the child.

Cone-beam computed tomography (CBTC) is commonly applied to pediatric dentistry as complement of radiograph exam. It allowed the exact location of the supernumerary tooth and the relation with adjacent structure. It has been used to plan the surgery procedure, allowing a conservative surgery, more comfort to children and to ensure a rapid procedure execution [3]. Thus, the aim of this study was to report a case, in which the presence of two mesiodens was diagnosed using CBTC exam, and the surgical intervention was conducted at two different stages.

A 7-year-old male was referred to the Positivo University Dental Clinic with complain about misalignment of his teeth at the right permanent maxillary incisor. During the anamnesis, the parents stated that a supernumerary tooth had been extracted from the midline area at age 4 (figure 1). The child had an uneventful medical history with no reports on any type of allergies. Dental exam did not show any type of asymmetry and the patient was at mixed dentition stage. Orthodontic examination showed that the patient exhibited Class I malocclusion without detectable abnormalities on soft tissues. Concerning to the teeth, the patient showed the rotation of the right permanent maxillary central and lateral incisors (figure 2A).

On cone-beam computed tomography (CBTC) and panoramic x-ray examinations, it was possible to observe the exact location of the supernumerary teeth, which was located buccal and mesially to the right permanent maxillary central incisor, without contact with the root of this tooth (figures 2B and C). Also, it could be observed a close proximity to the floor of the nasal cavity and the absence of bone between these structures, remaining only the nasal mucosa between the tooth and the nasal cavity.

CBTC showed the exact location to perform the initial osteotomy, at the mesial surface of the root of the left permanent central incisor (figure 3A). The tooth was removed as well as a cystic lesion (figure 3B). No communication with the nasal cavity was detected (figure 3C) and the wound was sutured (figure 3D). The surgical procedure was performed under general anesthesia.

At one-year follow-up appointment, it could be observed a better positioning of the left maxillary incisor on tooth arch (figure 4A) and a new bone formation as shown by the x-ray (figure 4B).

Figure 1 – Overview 4 years

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Figure 2 – A: clinical evaluation before surgery; B: projection cone beam computed tomography; C: panoramic image

Figure 3 – A: location, osteotomy of odontoseccion mesiodens; B: tooth removed; C: store oroantral bone without communication; D: after surgery

Figure 4 – A: clinical follow-up one year after; B: periapical radiograph after one year

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Discussion

Conclusion

Dental literature states that mesiodens occurs solo at the palatal area, with the tendency of natural eruption in the oral cavity. In this case report, the incidence of two mesiodens makes it unusual by the fact that one had erupted at the oral cavity but the other at the labial area was not able to erupt.

CBTC was the elected complementary exam, allowing the proper surgical procedure, reducing undesirable trauma to hard and soft tissue [1].

Moreover, CBTC images allowed to evaluate the exact location of the supernumerary tooth with adjacent structures, the inverted position of the mesiodens was detected, without contact with the root of tooth #21, and proximity to the floor of the nasal cavity. Therefore, the CBTC images were able to perform a reliable surgery planning and a conservative osteotomy, which avoided an unexpected communication with the nasal cavity.

The adequate treatment planning is relevant by the fact that these inverted supernumerary teeth are generally apical located and retained, requiring a more complex surgical intervention. Because of this apical location, care should be taken in relation to the root development stage of adjacent teeth.

According to Rao and Chidzonga [7], the removal of these teeth should be done only after the complete root closure of the adjacent permanent teeth. Moreover, the surgical intervention should be done with the child aging 8-10 years-old, when the roots of central and lateral incisors are developed and the child has a collaborative behavior.

On the other hand, it is agreed that the surgery moment depends on several factors, such as the type and position of the supernumerary tooth and its effect or potential effect on adjacent teeth. Thus, in this case, the surgical procedure was done at age 7 because of the unfavorable position of the tooth, located close to the floor of the nasal cavity and to the forming root of tooth #21. The indication of surgical treatment of unerupted mesiodens is a widely accepted proposal that can avoid or reduce orthodontic treatment time. This guideline was followed in this case.

The early diagnosis and planning of the surgical intervention either avoid or minimize the duration of orthodontic treatment, contributing to non-formation of cysts and longer impaction of permanent teeth.

The permanent maxillary left central incisor assumed a more favorable position on the arch and newly bone formation was observed at the mesiodens area.

References 1. American Association of Pediatric Dentistry.

Guideline on management of the developing dentition and occlusion in pediatric dentistry.

Pediatric Dentistry. 2008;30(7 Suppl):184-95.

2. Garvey MT, Barry HJ, Blake M. Supernumerary teeth – an overview of classification, diagnosis and management. J Can Dent Assoc. 1999;65(11): 612-6.

3. Gurgel CV, Costa AL, Kobayashi TY, Rios D, Silva SM, Machado MA et al. Cone beam computed tomography for diagnosis and treatment planning of supernumerary teeth. General Dentistry.

2012;60(3):e131-5.

4. Lawton H, Sandler PJ. Theapically repositioned flap in toothexposure. Dental Update. 1999;26: 236-8.

5. Meighani G, Pakdaman A. Diagnosis and management of supernumerary (mesiodens): a review of the literature. J Dent. 2010;7(1):41-9.

6. Rajab LD, Hamdan MA. Supernumerary teeth: review of the literature and a survey of 152 cases.

International Journal of Paediatric Dentistry.

2002;12(4):244-54.

7. Rao PV, Chidzonga MM. Supernumerary teeth: literature review. The Central African Journal of Medicine. 2001;47(1):22-6.

8. Van Buggenhout G, Bailleul-Forestier I. Mesiodens. European Journal of Medical Genetics.

2008;51(2):178-81.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):98-102

Case Report Article

Compound odontoma associated with dentigerous cyst in the anterior mandible – case report Radamés Bezerra Melo1 Yuri Edward de Souza Damasceno2 Celio Armando Couto da Cunha Junior3 Igor Vasconcelos Pontes4 Corresponding author: Yuri Edward de Souza Damasceno Rua Travessa 1.ª de Queluz, n. 226 CEP 66090520 – Belém – PA – Brasil E-mail: yuri.damasceno@hotmail.com 1 2 3 4

Department Department Department Department

of of of of

Surgery, Federal University of Ceará – Fortaleza – CE – Brazil.

Odontology, Federal University of Pará –Belém – PA – Brazil.

Oral and Maxillofacial Surgery, University Hospital João de Barros Barreto – Belém – PA – Brazil.

Oral and Maxillofacial Surgery, Hospital Batista Memorial – Fortaleza – CE – Brazil.

Received for publication: July 9, 2014. Accepted for publication: September 17, 2014.

Keywords: intraosseous; lesions; diagnosis; surgery, oral.

Abstract Introduction: The dentigerous cyst, also called a follicular cyst is an odontogenic cyst that develops in association with crown of an impacted tooth, predominantly in mandibular third molars of young patients. The Odontoma is a ectomesenquimal tumor of unknown origin that are more considered developmental malformations (harmatomas) than benign neoplasms. Occasionally, the dentigerous cyst is associated with odontoma. Objective: The article aims to report a case of surgical treatment of dentigerous cyst associated with compound odontoma and unerupted tooth in anterior region of the mandible. Case report: A male patient, 17 years of age, without systemic changes, was sent to the Center for Dental Specialties of Horizonte, Ceará, Brazil, specialty of Oral and Maxillofacial Surgery, for diagnosis and treatment of oral lesions visualized after periapical radiographic examination to determine failed eruption of element 42. Observing the periapical radiograph it was possible to visualize radiopaque lesion suggestive of a compound odontoma and a cystic capsule in association with the element 42. A panoramic radiograph

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was requested and it was planned a surgical removal of odontoma with curettage of bone cavity and removing the cystic capsule and element 42. There were no significant postoperative complications, the suture removal was performed 7 days after surgery where it was possible to observe a good healing, no swelling and no paresthesia.

Conclusion: The treatment of choice is surgical excision of the lesions with the tooth associated to the cyst, it should be performed with proper planning, avoiding injury to vital structures and should not be delayed in order to avoid possible occlusion sequelae.

Introduction The dentigerous cyst, also called a follicular cyst is an odontogenic cyst that develops in association with crown of an impacted tooth, predominantly in mandibular third molars of young patients. Lesions are often asymptomatic unless associated with an infectious process and is generally diagnosed in routine radiographs [6].

The radiographic features of dentigerous cyst shows a radiolucent area with sclerotic border well defined and attached to the neck of the tooth unerupted. May be accompanied by tenderness, swelling, tooth mobility or tooth displacement when it reaches the diameter of 2 cm [1].

Occasionally, the dentigerous cyst is associated with impacted teeth or odontoma. Its association with odontoma is seen in 27.6% of cases [7].

The Odontoma is aectomesenquimal tumor of unknown origin, may be related to the presence of impacted teeth, trauma, local infection and dentigerous cysts [14]. Among odontogenic tumors, odontoma is the most prevalent in the jaws [9], representing 70% of odontogenic tumors found [8, 2, 16], are more considered developmental m a l for m at ion s (h a r m atom a s) t h a n b en i g n neoplasms.

The article aims to report a case of surgical treatment of dentigerous cyst associated with compound odontoma and unerupted tooth in the anterior region of the mandible.

Case report A male patient, 17 years of age, without systemic changes, was sent to the Center for Dental Specialties of Horizonte, Ceará, Brazil, specialty of Oral and Maxillofacial Surgery, for diagnosis and treatment of oral lesions visualized after periapical radiographic examination to determine failed eruption of element 42. Observing the periapical radiograph it was

possible to visualize radiopaque lesion suggestive of a compound odontoma, being possible to view multiple denticles.

Panoramic radiograph and clarck technique was requested for better visualization of the lesions and the location of the element 42 (Figure 1).

Figure 1 – Panoramic radiograph

It was planned a surgical act to remove the odontoma with curettage of bone cavity and removing the cystic capsule and element 42, because the element was found badly positioned with proximity to the roots of the elements 41 and 42, risking of root resorption in the attempted traction.

To complement the surgical plan, the Clark technique was realized to found that the Odontoma and element 42 would be best addressed by the vestibular access, due to its position in front of the roots of the mandibular anterior teeth.

The surgica l protocol consisted of ex t ra oral antisepsis performed with povidone iodine

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topica l (R iodeine ®) a nd int raora l performed w it h chlorhex idinegluconate 0.12%; regiona l a nest hesia by blocking t he bilatera l menta l nerve a nd complementation w it h infilt rative techniques. The Novak-Peter incision was made in the region of element 43 to 41. After detashment the mucoperiosteal flap, it was performed an osteotomy with surgical round burs in high rotation under irrigation with saline 0.9% for access to denticles and the element 42, which were removed with straight and curved extractors (Figures 2 and 3).

The flap was repositioned, and the suture was performed by simple sutures isolated.

The patient was properly instructed to the postoperative care and medicated with corticosteroids, antibiotics, analgesic and anti-inflammatory. There were no significant postoperative complications, the suture removal was performed 7 days after surgery where it was possible to observe a good healing, no swelling and no paresthesia (Figure 3).

Figure 4 – Seventeen-days clinical follow-up

The cystic material was sent for histopathological analysis, which indicated a squamous epithelial tissue with 2-4 layers surrounded by a capsule of fibrous connective tissue, confirming the hipothesis of dentigerous cyst (Figure 4).

Figure 2 – Incision, mucoperiostal flap, osteotomy and bone cavity after removal of denticles

Figure 5 – Histopathological of dentigerous cyst

Discussion

Figure 3 – Denticles removed

The World Hea lt h Orga ni zat ion i n 1992 ranked the odontomas into two types, according to morphological differentiation: compound and complex [5]. The compound odontoma was defined

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as an injury that stems from an exag gerated proliferation of the dental lamina, showing all dental tissues in an orderly manner and are often presented in the form of denticles. Radiographically can characterize the compounds odontoma as a set of structures similar to the teeth, may have a variable sizes and shapes, surrounded by a radiolucent area. In the complex odontoma, dental tissues are found like an amorphous calcified mass and radiographically visualized by a uniform radiopacity with irregular edges surrounded by radiolucent space [18].

The odontomas are detected most commonly in the first two decades of life, with no gender predilection [4]. There is a higher frequency of compound odontoma comparing to the complex and the most frequent location of compound odontoma is the anterior region of the maxilla, and complex odontoma the posterior regions of the jaws [2, 12, 15].

In most cases the lesions are asymptomatic, although they may cause thickening of the cortical, being discovered on routine radiographic examination or to determine the reason for an eruption failure of a particular tooth, like in this case [3].

Odontomas may be associated with delayed eruption of permanent teeth and the development of cystic lesions such as dentigerous cyst. These cases are not rare (27.6%) and the diagnosis is based on radiological aspects and histopathological analysis of the lesions, in some cases radiological aspects may resemble fibro-osseous lesions [17].

This case shows a compound odontoma evidenced in imaging exams by multiple denticles encircled and a radiolucent area in anterior region of mandible associated a dentigerous cyst in the anterior region of the mandible. The surgical exposure showed the cystic lesion attached to the neck of the tooth unerupted.

The dentigerous cyst predominantly affects mandibular third molars of young patients, followed by maxillary canine, mandibular premolar and maxillary third molar. It is usually asymptomatic and may be associated with mobility or displacement of teeth, radiographically characterized by a radiolucent lesion with a well-defined sclerotic margin associated with a crown of a tooth unerupted [1, 10]. Histopathological consists of a fibrous conjunctive tissue capsule and an epithelial lining of two to four layers of flattened cells may or may not present a keratinized surface [13].

Complications associated with dentigerous cysts are pathological bone fracture, loss of permanent teet h, bone deformit ies a nd development of ameloblastoma or malignancies such as squamous

cell carcinoma and intraosseousmucoepidermoid carcinoma [7, 10, 13].

The treatment of odontoma is surgical excision, such treatment has great success with very rare cases of recurrence, occurring bone repair [15].

The indicated treatment for dentigerous cysts is surgical excision with removal of the involved tooth, in some cases may be necessary marsupialization of the lesion for the reduction of bone defect before surgical intervention [10].

This case was treated by surgical excision of the lesions and the associated tooth. The choice of surgical traction of the unerupted tooth was avoided because of its difficult location and possibility of resorption of adjacent elements. The size of the lesion did not require marsupialization before removal and the patient remained with a satisfactory amount of surrounding bone.

The diagnosis of the lesions is done mainly by initial imaging exams and subsequently confirmed by histopathological analysis. The failure to diagnose or treatment can lead to disorders ranging from aesthetic and phonetic until drastic occlusal changes [19].

Conclusion The compound odontoma is benign malformation that the diagnosis is clinical and radiographic, usually asymptomatic, with slow evolution and may be associated with other disorders such as dentigerous as outlined in this case. The treatment of choice is surgical excision of the lesions with the tooth associated to the cyst, should be performed with proper planning and as soon as possible, avoiding injury to vital structures and possible occlusion sequelae.

References 1. Bocher L, Wonderberg Y, Ban-Zir J. Radiographic features of large cysts lesions of jaw in children.

Paediatri Radiol. 2003;33:3-6.

2. Cardoso LC, Miyahara GI, Magro Filho O, Garcia Júnior IR, Soubhia AMP. Odontoma combinado associado a dentes não irrompidos: relato de casos clínicos. Rev Odont Araçatuba. 2003 Aug/ Dec;24(2):47-51.

3. Cildir SK, Sencift K, Olgac V, Sandalli N. Delayed eruption of a mandibular primary cuspid associated with compound odontoma. J Contemp Dent Pract. 2005;6:152-9.

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4. Freitas DA, Freitas VA, Mol VC, Mana Neto L, Mol VC. Elemento dental impactado por odontoma composto. Rev Bras Cir Cabeça Pescoço. 2009 Jul/Aug/Sep;38(3):198-9.

5. Hisatomi M, Asaumi J, Konouchi H, Holanda Y, Wakasa T, Kish K. A case of complex odontoma associated with an impacted lower deciduos second molar and analysis of the 107 odontomas. Oral Dis. 2002;8:100-5.

6. Ikeshima A, Tamura Y. Differential diagnosis between dentigerous cyst and benign tumor with an embedded tooth. J Oral Sci. 2002;44:13-7.

7. Kaugars GE, Miller ME, Abbey LM. Odontomas.

Oral Surg Oral Med Oral Pathol. 1989;67:172-6.

8. Lukes SM, Wachter KM. Compound odontoma: a case study. The Journal of a Dental Hygiene.

2003;77(1):47-9.

9. Mehra P, Singh H. Complex composite odontoma associated with impacted tooth. N Y State Dent J. 2007;73(2):38-40.

10. Motamedi MH, Talesh KT. Management of extensive dentigerous cysts. Br Dent J. 2005;198:203-6.

11. Morning P. Impacted teeth in relation to odontomas. Int J Oral Surg. 1980;9:81-91.

12. Nóia CF, Oliveira FAC, Pinto JMV, Santos WHM. Odontoma composto. RGO. 2008 Apr/ Jun;56(2):213-7.

13. Neville BW, Damm DD, Allen CM, Bouquot JE. Oral and maxillofacial pathology. 3. ed. St. Louis: Saunders Elsevier; 2009.

14. Santos TCRB, Sampaio RKPL. Aspectos clínicos, radiográficos e histopatológicos dos odontomas. Rev Bras Odontol. 1981;38(2):2936.

15. Serra-Serra G, Berini-Aytés L, Gay-Escoda C. Erupted odontomas: a report of three cases and review of the literature. Med Oral Patol Cir Bucal.

2009 Jun;14(6):299-303.

16. Silva LF, David L, Ribeiro D, Felino A. Odontomas: a clinicopathologic study in a portuguese population. Quintessence Int. 2009 Jan;40(1):61-72.

17. Smith JL, Kellman RM. Dentigerous cysts presenting as head and neck infections. Otolaryngol Head Neck Surg. 2005;133:715-7.

18. Tomizawa M, Otsuka Y, Noda T. Clinical observations of odontomas in Japanese children: 39 cases including one recurrent case. Int J Paediatr Dent. 2005;15(1):37-43.

19. Veis A, Tziafas D, Lambrianidis T. A case report of a compound odontoma causing delayed eruption of a central maxillary incisor: clinical and microscopic evaluation. J Endod.

2000;26(8):477-9.

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Case Report Article

Free gingival graft to increase gingival dimensions in Down syndrome patients: clinical case report Carla Hariene Montanha1 Maria Estela Plens1 Henrique Scheffer Ferreira1 Luiz Augusto Ribas1 Vinicius Augusto Tramontina1 João Armando Brancher1, 2 Andréa Paula Fregoneze1 Corresponding author: Andréa Paula Fregoneze Avenida Manoel Ribas, n. 750, apto 303 – Mercês CEP 80510-020 – Curitiba – PR – Brasil E-mail: afregoneze@gmail.com 1 2

Department of Dentistry, Pontifical Catholic University of Paraná – Curitiba – PR – Brazil.

Department of Dentistry, Positivo University – Curitiba – PR – Brazil.

Received for publication: November 7, 2013. Accepted for publication: September 17, 2014.

Keywords: Down syndrome; free gingival graft; periodontal disease.

Abstract Introduction: Down Syndrome (DS) patients have increased susceptibility to the development of periodontal diseases by the occurrence of several factors, such as inadequate hygiene, mouth breathing, dental morphology, leukocyte reduction and increased inflammatory mediators. Objective: This study aimed to review the literature on the main aspects of DS and present a clinical case of a DS patient treated with basic periodontal therapy and free gingival graft surgery. Case report: DS patient, leucoderma, aged 26 years showed gingival recession and little amount of keratinized tissue in the area of teeth #31 and #41. After surgery, there was an increase in the keratinized tissue band. Conclusion: The free gingival graft surgery performed in DS patients was effective, as the increase of keratinized tissue band occurred.

104 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):103-8 Montanha et al. â&#x20AC;&#x201C; Free gingival graft to increase gingival dimensions in Down syndrome patients: clinical case report

Introduction Down's syndrome (DS) or trisomy 21 is a chromosomal disorder resulting from the presence of an extra chromosome 21, in all cells or part of them. It is the most common birth defect and the most recognized form of mental retardation, appearing in about one in every 700 live births.

Although the syndrome has been described many years before, it was named by John Langdon Down in 1866 [8].

Dreux et al. [5], Biselli et al. [2], and Valencia et al. [12] explained that three types of chromosome 21 abnormalities can be described: a) free trisomy 21, b) mosaicism, and c) translocation. In about 95% of DS cases, the anomaly occurs because of an extra total chromosome 21 in all cells. In 2% of cases of DS, mosaicism is observed, meaning the anomaly is located in only some cells of the body, while others have normal chromosomes.

Translocation involves the long arm of acrocentric chromosomes. This defect can be transmitted over several generations, resulting in chromosomally abnormal products with complete aneuploidy.

The risk of syndrome recurrence in cases of free trisomy mosaicism and usually it is not repeated in siblings of DS people, while the translocation can be recurrent [2, 5, 12].

Among the main risk factors for DS, stand out advanced maternal age, increasing exponentially after 35 years of age; previous child with DS or other chromosomal abnormality; parietal translocation and parents with chromosomal disorders [3].

Girirajan [6] cited some clinical features of DS, among which we highlight the severe mental retardation, facial profile characteristics, short stature, delayed speech development, chronic ear infections with consequent loss of hearing and hypotonia. The characteristics of the facial profile consist of epicanthus, flattened nasal plan, palpebral fissures and protruding tongue. DS patients may also exhibit congenital heart disease between 40 and 50% of the cases an increased risk for developing Alzheimer's disease, acute megakaryocytic leukemia, Hirschsprung's disease and duodenal atresia.

The most frequent general DS problem is mental retardation associated with a high incidence of congenital heart disease and abnormalities of the gastrointestinal tract. In addition to these changes, hypothyroidism, celiac disease, type I diabetes mellitus, transient myeloproliferative disease occur frequently in these syndromic people [10].

Many oral manifestations inherent to DS were described by Amano et al. [1] and Davidovich et al.

[4], e.g., macroglossia, cleft lip and tongue, maxillary

atresia, malocclusion, high palate, hypersalivation, microdontia, agenesis, conoid teeth, eruption retardation, low incidence of caries, mouth breathing and open bite. Surprised with the low prevalence of caries despite the presence of risk factors such as cariogenic diet consumption, mouth breathing, difficulty in oral hygiene (resulting from mental retardation), the authors associated this condition with the high average values of pH and buffer capacity checked in sialochemical analysis.

The severity of periodontal disease in individuals with DS is associated with different local factors of the oral cavity and also to the problems associated with systemic disease gene itself. DS patients have an inability to maintain proper oral hygiene.

Other conditions contribute to colonization of periodontal pathogens such as mouth breathing, tooth morphology and acute necrotizing ulcerative gingivitis. There is evidence that immunity is impaired due to the reduction of neutrophils, T lymphocytes and increasing the production of inflammatory mediators and proteolytic enzymes.

All this can help increase the prevalence and aggravate severity of periodontal disease in DS people [8].

The mucogengival deformities, such as changes i n t he di mensions of t he mucosa a n i n t he morphological characteristics often have an impact on patients in terms of function and aesthetics.

Although clinical evidence shows that no attached gingiva minimum value is required to maintain gingival health, there are clinical situations, such as thin or absent gingiva which make it difficult to maintain the hygiene at that location, causing plaque accumulation, inflammation, and consequently the loss ligament insertion [11].

The trauma resulting from inadequate or excessive brushing, gingival inflammatory reactions, bone dehiscence, poor positioning of the teeth, and orthodontic movement are considered predisposing factors for gingival recession. The gingival recession is classified as Class I when it extends below the mucogingival junction, and class II when it reaches these areas [9]. In such cases, the free gingival graft (FGG) is a surgical technique introduced to address the lack of keratinized tissue, leading to increase in the size of this tissue [11].

Because of the lack of studies on the treatment of periodontal morphological changes in DS patients, this study aimed to present a case in which FGG was performed to increase the size of that tissue. Such intervention was carried out by multidisciplinary treatment of the Specialization Course in Periodontics and Discipline for Special Patients of the Pontifical Catholic University of ParanĂĄ (PUC-PR).

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Clinical case A male, leucoderm DS patient aged 26 years was referred to treatment. During the anamnesis, the mother reported that she discovered the pregnancy at 44 years of age and that this went uneventfully.

The delivery was normal, with no complications, the baby cried at birth and sucked in the first 24 hours.

Its development was satisfactory. He was breastfed until six months. At eight months, his first tooth erupted and crawled at nine months. At two years of age, he started to stand up alone and talk. He started to wear glasses at 16 years of age.

The survey of current medical history revealed that the only systemic problem is a tremor in his eyes. Accordingly, the patient has been doing eye exercises for more than three years and uses Endura®, which is an ocular lubricant. As regards the behavioral aspect, the patient was very open,

since related pleasantly with all professionals. The mother also told the team that he was irritated only when some people fought or talking loudly near him.

He was referred to the Discipline of Dentistry for Patients with Special Needs of PUC-PR by the Association of Parents and Friends of Exceptional People (Apae), to receive dental treatment. The patient had received previous dental treatment at this same Association.

During intraoral clinical examination, we verified plaque accumulation and gingivitis. The gingiva on the labial surface of the mandibular incisors showed little amount of keratinized mucosa and recession. The analysis of occlusion showed a convex profile, Class III malocclusion, left posterior cross bite and crowding in the anterior region. The initial clinical condition of each tooth is described in figure 1.

Figure 1 – Patient’s initial odontogram

Prior to dental procedures, interproximal and panoramic radiographs were taken. Panoramic radiograph showed the agenesis of the maxillary and mandibular third molars and the presence of included maxillary canines. Then, the basic periodontal therapy was carried out, which included root scaling, planning and polishing. Oral hygiene instructions were transmitted to the mother and the patient so that both continue motivated to maintain oral health. The next step was the application of fluoride varnish.

As the patient had small amounts of keratinized tissue, gingival recession in teeth 31 and 41 (figure 2A), the augmentation of the gingival dimensions was programmed in order to improve the protection of periodontal supporting tissue. The technique used was FGG: initially, the receptor site was prepared through an incision from the mucogingival junction towards apical direction and a flap was obtained from the mesial of tooth 32 to the distal 42 (figure 2B).

After mapping FGG receptor area, the map was transferred, with the likely size of the graft, to the

106 â&#x20AC;&#x201C; RSBO. 2015 Jan-Mar;12(1):103-8 Montanha et al. â&#x20AC;&#x201C; Free gingival graft to increase gingival dimensions in Down syndrome patients: clinical case report

donor area between right maxillary premolars and first molar, on the palate. With the aid of a 15C blade, a superficial incision was made around the aluminum map to demarcate the graft area to be removed. After this initial incision and removal of the map, the depth incisions were performed at a distance of 2 to 3 mm for the removal of epithelialized free graft.

After removal of tissue from FGG donor site (figure 2C), local hemostasis was promoted with bismuth subgallate and then the wound was protected with surgical cement (figure 2D). FGG removed from the donor area was sutured to the receptor site with simple and suspensory suture, and then the area was protected with surgical cement (figures 2E, F and G).

Elapsed one week after surgery, the sutures were removed and the presence of a reddish bleeding

tissue with characteristics of vitality of the graft was observed. It was also found desquamation of graft epithelial tissue, which is considered normal at this healing step. Ibuprofen 600 mg, 3 times daily for 4 days was prescribed to reduce swelling and to prevent inflammation.

A f ter t wo mont hs, t here wa s a g re at incorporation of the graft to the receptor site.

After 6 months, 1 year and 2,5 years, there has been significant growth in the keratinized mucosa band, thus achieving the increase of gingival tissue dimensions (figures 2H, I, and J). The patient continues to be followed-up to receive oral health maintenance and treatment of included upper canines at the Clinics of the Discipline of Dentistry for Patients with Special Needs of PUC-PR.

A

B

C

D

E

F

G

H

I

J

Figure 2 â&#x20AC;&#x201C; Sequence of FGG surgical procedure. A. Initial clinical aspect with gingival recession of teeth #31 and #41; B. preparation of receptor site; C. tissue removal of the donor site; D. protection of donor site with surgical cement; E. FGG aspect removed from the donor site; F. tissue sutured on receptor site; G. protection with surgical cement on receptor site; H. 6 month follow-up; I. 1 year follow-up; J. 2,5 year follow-up

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Discussion

Conclusion

Among the main DS risk factors there is advanced maternal age, significantly increasing after 35 years of age [3]. This statement meets the clinical case study, as in anamnesis, the mother reported that the pregnancy occurred at 44 years of age. Corroborating the descriptions of Girirajan [6], the following features were noted in the patient: epicanthus, palpebral fissures, flat nasal plan. On the other hand, hypotonia, chronic ear infections and hearing loss have not been verified.

Similarly, the delay in speech development, quoted by the same author, differs from the information obtained in the anamnesis, since the mother said the baby started talking at 2 years old. The severe mental retardation [6] has not been observed because the patient had amazing ability to paint. With regard to the systemic conditions, none was found. The only problem was that the patient had the tremor in his eyes.

Among inherent DS oral manifestations [1, 4] maxillary atresia, malocclusion, fissured tongue, low incidence of caries, mouth breathing and agenesis were present. In contrast, cleft lips, high palate, hypersalivation, microdontia and conoid teeth were not observed.

Morgan [8] said that the severity of periodontal disease in persons with DS is associated with severa l factors, such as fa ilure to ma inta in proper oral hygiene, mouth breathing and tooth morphology. Despite these conditions confirmed in the present study patient, periodontal disease was not severe.

Therefore, i n order to solve t he biof i lm accumulation and gingivitis, initially the mother and the patient were instructed on the proper technique for oral hygiene. Then root scaling, planning, and polishing were executed.

FGG was justified by the fact that the patient has Class I gingival recession [9] on teeth #31 and #41, and little amount of keratinized tissue on the same region [11]. The team was concerned on the continuity of insertion ligament loss in these teeth, which is a consequence of the presence of mucogingival [11]. FGG surgery was satisfactory, because both the recession and the alteration of mucosa dimensions were solved. The surgery goal was to improve the function, because the patient was asymptomatic and did not present esthetic demands.

FGG surgery performed on DS patient was effective, because the keratinized mucosa band increase, thus achieving the increase of gingival dimensions.

References 1. Amano A, Murakami J, Akiyama S, Morisaki I. Etiologic factors of early-onset periodontal diseasein Down syndrome. Japanese Dental Science Review. 2008 Jul;44:118-27.

2. Biselli J, Bertollo EG, Ruiz M, Bertelli EP. Cytogenetic profile of Down syndrome cases seen by a general genetics outpatient service in Brazil.

Down Syndrome Research and Pratice. 2009 Feb;12(3):4.

3. Davidson MA. Primary care for children and adolescents with Down syndrome. Pediatric Clinics of North America Syndrome. 2008 Oct;55:1099111.

4. Davidovich E, Aframian DJ, Shapira J, Peretz B. A comparison of the sialochemistry, oral pH, and oral health status of Down syndrome children to healthy children. International Journal Of Paediactric Dentistry. 2010;20:235-41.

5. Dreux S, Olivier C, Dupont JM, Leporrier N, Group S, Oury JF et al. Maternal serum screening in cases of mosaic and translocation Down syndrome. Prenat Diagn. 2008 Jul;28:699-703.

6. Girirajan S. Parental-age effects in Down syndrome. Journal of Genetics. 2009 Apr;88:914.

7. Mégarbané A, Ravel A, Mircher C, Sturtz F, Grattau Y, Rethoré MO et al. The 50th anniversary of the discovery of trisomy 21: the past, present, and future of research and treatment of Down syndrome. Genet Med. 2009 Sep;11(9):611-6.

8. Morgan J. Why is periodontal disease more prevalent and more severe in people with Down syndrome? Spec Care Dentist. 2007;27(5):196201.

9. Müller HP, Eger T, Schorb A. Alteration of gingival dimensions in a complicated case of gingival recession. Int J. Periodont Rest Dent.

1998;18(4):345-53.

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10. Ram G, Chinen J. Infections and immunodeficiency in Down syndrome. Clinical and Experimental Immunology. 2011 Jan;164:9-16.

11. Silva CO, Ribeiro EDP, Sallum AW, Tatakis DN. Free gingival grafts: graft shrinkage and donor-site healing in smokers and non-smokers.

J Periodontol. 2010 May;81(5):692-701.

12. Valencia LG, Angles MMR, Hernández AM, Gonzáles MRB. Down’s syndrome associated with a balanced Robertsonian translocation 13;14 maternally transmitted in the product of a twin diamniotic pregnancy. Bol Med Hosp Infant Mex. 2011;68(3):206-10.

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PROCEEDINGS OF THE 3rd ICOI-BRAZIL 2014 – INTERNATIONAL CONGRESS OF ORAL IMPLANTOLOGY Tatiana Miranda Deliberador: Scientific Board of the 3rd ICOI-Brazil Felipe Rychuv Santos, Caroline Auersvald, Carmen L. Mueller Storrer, Allan Fernando Giovanini, Tatiana Miranda Deliberador, Eduardo Morais and Elizabeth Ting: Commission of reviewers of scientific posters of the 3rd ICOI-Brazil

Research Studies

Evaluation of cranial bone repair in experimental model treated with bisphosphonates.

Histological and hystometric study in rabbits Juliana de Sousa Vieira1 Isabela Gohringer1 Emanuelle Cunha1 Allan Fernando Giovanini1 João César Zielak1 Tatiana Miranda Deliberador1 Corresponding author: Juliana de Sousa Vieira E-mail: juliana_vieira28@hotmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: bisphosphonates; rabbits; bone healing.

Introduction: Bisphosphonates inhibit osteoclast activity and are indicated for the treatment of osteoporosis and osteolytic tumors, but its effect in the jaws are still doubtful. Objective: To evaluate the repair and cranial bone remodeling after systemic application of alendronate (ALN) through histological and histometric analysis.

Material and methods: 28 rabbits were randomly divided into two groups, control (C) and bisphosphonate (B). The groups were divided into two subgroups for euthanasia at 15 and 60 days postoperatively.

Group B received 3 systemic ALN applications at a dose of 0.2 mg / kg for 4 weeks. Group C received saline applications in the same way and at the same time. The animals underwent surgery to create two non-critical defects of 5mm in diameter on the skull. After euthanasia, histological and histometric analyses were performed.

Data were subjected to statistical analysis (ANOVA ρ≤ 0.05). Results: Histologically, group C at 15 and 60 days showed connective tissue, trabecular bone and compact bone with osteoblastic cells. In Group B, at 15 days, we observed the presence of connective tissue, osteoblastic cells, and intense compact bone neoformation. At 60 days, the defect showed a large amount of newly formed bone with a compact dense connective tissue surface and the presence of fat cells. The histometric analysis showed statistically significant differences between groups for bone areas measures and connective tissue. Conclusion: Systemic application of ALN at a dose of 0.2 mg / kg favored the repair and the cranial bone remodeling.

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Osteocalcin immunoprofile assessment on bone repair in critical size defects treated with white subcutaneous adiposetissue in rat and rabbit animal model Tadeu Vieira Barros1 Caroline Moreira Auersvald1 Letícia de Souza Moraes1 Tatiana Miranda Deliberador1 Lucienne Miranda Ulbrich1 Thalyta Verbicaro1 Corresponding author: Thalyta Verbicaro E-mail: thalytaverbicaro@hotmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: subcutaneous fat; bone regeneration; osteocalcin.

Introduction: Adipose tissue can influence the tissue metabolism and has potential to differentiate into skeletal, cartilage and endothelial tissue. Objective: To evaluate the osteocalcin immune expression in bone repair of critical defects treated with white adipose tissue in rats and rabbits. Material and methods: 14 rats and 14 rabbits were used. A critical defect was performed in the skull of each animal. The animals were divided into 4 groups: RC (rat control), RaC (rabbit control), RAT (rat adipose tissue), RaAT (rabbit adipose tissue). In groups RC and RaC, the gap was filled with blood clot.

In groups RAT and RaAT, the defect was filled with macerated white subcutaneous adipose tissue graft. Euthanasia of groups RC and RAT was at 30 days and groups RaC and RaAT at 40 days.

Histological and immunohistochemical analyses of osteocalcin were performed. The data were submitted to descriptive statistics (mode).

Results: In both experimental models, osteocalcin immunostaining was observed. However, group RaAT had higher immunoreactivity between adipocytes than did group RAT. In groups RC and RaAT, the surgical wound was filled with collagen fibers. In group RaAT the defect was filled with collagen fibers present between the adipocytes fibers. Furthermore, chronic inflammation was observed and new bone formation signals. Conclusion: Both graft models showed low osteogenic capacity. However, rabbit animal model had more evident immunoreactivity and a larger amount of bone matrix and adipocytes.

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Evaluation of hard palate tomographic regions for skeletal anchorage devices installation Giovani Lago1 Mauro Toma1 Ricardo Lima Navarro1 Ana Cláudia de Castro Ferreira Conti1 Paula Vanessa Pedron Oltramari Navarro1 Thais Maria Freire Fernandes1 Corresponding author: Giovani Lago E-mail: giovanilago@yahoo.com.br 1

Dentistry Course, North Paraná University – Londrina – PR – Brazil.

Keywords: orthodontics; implants; cone beam CT; hard palate.

Introduction and Objective: To quantitatively evaluate the hard palate areas available for installation of skeletal anchorage devices.

Material and methods: The sample consisted of 69 cone beam computed tomography of individuals from private radiology clinic (mean age 17.23 ± 7.14 years). Osoftware Dolphin Imaging® was employed to assess bone palate availability in coronal reconstructions of 3, 18, and 30 mm from posterior wall of the incisive foramen. In each reconstruction, the thickness was 1.5 mm and 9 mm from the palatal suture bilaterally. Bone availability in the different regions of the palate was evaluated through analysis of variance (ANOVA) for repeated measures followed by Bonferroni test. In addition, the age and gender influence was studied using t test. Results: Bone availability increased in the direction along the anterior-posterior sutures. In the reconstructions of 5 and 9 mm, this availability tends to decrease with respect to sutures, except for 9 mm reconstruction, in which tends to increase in the region of 3 mm. There were no statistically significant differences in bone availability regarding to age. Greater bone availability was found for males in the anterior region in the areas of 1 and 5 mm. Conclusion: Based on the results obtained, the areas of best available bone for installation of skeletal anchorage devices are within 1 mm of the sutures in the anterior-posterior direction and 3 mm from the incisive foramen along the medial-lateral direction.

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Histological and histomorphometric evaluation of low laser therapy (LLT) and platelet rich plasma (PRP) in the process of bone repair. Experimental study in rats Rafael Zancan1 Lucas Oliveira Azevedo1 Ana Claudia Fonseca1 Thiago Jonasson1 Marcela Claudino da Silva1 Allan Fernando Giovanini2 Melissa Rodrigues de Araujo2 Corresponding author: Rafael Zancan E-mail: zancan.rafael@gmail.com 1 2

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Graduate Program in Clinical Dentistry, Positivo University – Curitiba – PR – Brazil.

Keywords: low laser therapy; platelet rich plasma; healing.

Introduction: The process of bone repair occurs after injuries to the body. The low laser therapy (LLT) increases metabolism, cell proliferation and maturation, and decreases the inf lammatory mediators. PRP releases proteins and growth factors associated with the repair. Objective: To evaluate the bone repair process after the PRP and LLT. Material and methods: A u5 mm surgical c defect was performed in the skull of 66 Wistar rats. The bone was particulate and used as autogenous bone graft (ABG). The animals were divided into four groups (G1: PRP, LLT and ABG; G2: PRP and ABG; G3: LLT and ABG; G4: only ABG). Euthanasia was performed at 30 and 60 days. The specimens were subjected to histological and histomorphometric assessments and the hard tissues were evaluated regarding to the degree of bone formation, inflammatory infiltrate and amount of connective tissue. Results: G1: Significant areas of mature bone graft, mild inflammatory infiltrate and marked osteoblasts. G2: Discrete presence of immature bone and mature bone, connective tissue in significant amounts and scattered foci of inflammatory infiltrate. G3: Extensive areas of mature bone with mild immature bone area. Sparse inflammatory infiltrate foci at 30 days, and their absence to 60 days. G4: Large areas with presence of immature bone and mature bone, with mild inflammatory infiltrate.

Conclusion: LLT minimized the inflammatory process resulting in its absence after less time. The PRP and graft association favors the presence of mature bone (graft).

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Comparative study between the digital and conventional radiography in the process of bone repair with low-level laser therapy (LLLT) and platelet-rich plasma (PRP) Lucas Oliveira Azevedo1 Rafael Zancan Mobile1 Ana Claudia Fonseca1

Thiago Jonasson1 Rafaela Scariot1 Allan Fernando Giovanini1 Melissa Rodrigues de Araujo1 Corresponding author: Lucas Oliveira Azevedo E-mail: lucas.azevedo.up@gmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: low laser therapy; platelet rich plasma; healing.

Introduction: The process of bone repair occurs after injuries to the body. The low laser therapy (LLT) increases metabolism, cell proliferation and maturation, and decreases the inf lammatory mediators. The PRP releases proteins and growth factors associated with the repair. Objective: To evaluate through digital and conventional radiography bone repair after PRP and LLT. Material and methods: a u5 mm surgical defect was performed in the skull of 66 Wistar rats. c The bone was particulate and used as autograft (AG). The animals were divided into four groups (G1: PRP, LLT and AG); G2: PRP and AG; G3: LLT and AG; G4: only AG). Euthanasia was carried out at 30 and 60 days. Conventional (70kVp, 7mA Dhabi Atlante®) and digital (Kodak RVG 5100) x-rays of the calvaria were taken. Three calibrated examiners performed an evaluation of both images on the bone formation, giving score 1-5, 1 meaning no bone formation and 5 meaning between 75% and 100% of the defect filled with bone. Results: The weighted Kappa test (0.5634 to 0.7813, 95%) showed agreement among the examiners in the evaluation of digital and conventional radiographic images. There was substantial agreement on digital radiographic analysis while in the conventional radiographic analysis, the agreement was moderate. G3 showed the highest score of bone formation by digital and conventional evaluations followed by G2 / G1 and G4. The Mann Whitney test showed statistically significant difference in bone formation only in G1 (p = 0.049) when comparing the digital and conventional images. Conclusion: The process of bone repair is best assessed by digital radiography. FINANCIAL SUPPORT: Positivo University.

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Aesthetic perspective from the dental papilla evaluation in the upper anterior region Claudia A. Pimenta1 João César Zielak1 Carlos Eduardo Francischone2 Corresponding author: Claudia A. Pimenta E-mail: claudia.line@hotmail.com Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Department of Operative Dentistry, Endodontics and Dental Materials of Bauru Dental School, São Paulo University – Bauru – SP – Brazil.

1 2

Keywords: gingival papilla; gingival aesthetics; aesthetic perception.

Introduction and Objective: This study aimed to compare the aesthetic perception of lay people and dentists about the appearance of the papillae in the upper anterior region in its height and extension changes. Material and methods: Eighty-five lay people (35 with prostheses and 50 without prostheses) and 55 dentists (31 implantodontists or periodontists and 24 from other specialties) evaluated the images, classifying them as very satisfactory, satisfactory, unsatisfactory, very unsatisfactory. Seven images were evaluated: 1) control image of a harmonic dental-gingival smile; 2) reduction of 1 mm in all the gingival papilla between teeth #13-#23 from the control image; 3) reduction of 2 mm between teeth #13-#23 from the control image; 4) reduction of 1 mm with the presence of black space of all gingival papillae between teeth #13-#23 from the control image; 5) reduction of 1 mm with the presence of black space between the teeth #21-#22; 6) reduction of 1 mm with the presence of black space between the teeth #11-#21; 7) increased by 1 mm in all the gingival papilla between teeth #13-#23 from the control image. The validation of the questionnaire was done by Cronbach's α test. Data were subjected to Kruskal-Wallis. Results: The reliability of the questionnaire was considered high. Conclusion: Considering the papillary changes from the aesthetic perspective, it can be concluded that dentists were more critical than the lay people.

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Analysis of mandibular bone remodeling in rabbits treated with bisphosphonate Emanuelle Cunha1 Giovanna Portela1 Juliana de Sousa Vieira1 João César Zielak1 Tatiana Miranda Deliberador1 Allan Fernando Giovanini1 Corresponding author: Emanuelle Cunha E-mail: cunhaemanuelle@hotmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: bisphosphonates; bone regeneration.

Introduction: The bisphosphonates (BPs) are drugs used to treat various bone pathologies. Although there are reports that show positive aspects of trabecular bone remodeling in patients treated with BPs, the literature also reveals the presence of necrosis and loss of bone tissue when subjected to surgical action in bone of skull and face, revealing a negative effect of BPs on reparative mineralization. Objective: The objective of this study was to evaluate by histomorphometry and radiographic analysis the mandibular bone healing in rabbits treated with bisphosphonates. Material and methods: In this study, 56 rabbits without previous disease were used. A circular non-critical surgical defect, measuring 5 mm in diameter, was created in the jaw of each rabbit to mimic tooth loss.

Randomly, the rabbits were treated with BPs (n = 28), 14 rabbits per group, and the remaining were untreated (n = 28). Periods of euthanasia were 15 and 60 days after surgery, with a number of 7 rabbits per period in each group. The analyses were performed histologically and radiographically. Results: The results showed that when the jaw defects were treated with BPS, they demonstrated higher bone deposition than those of control group. Conclusion: Within the limits of this study it can be concluded that the use of bisphosphonates has a positive effect on mandibular bone remodeling in rabbits.

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Immunoprofile ratio between osteocalcin (OC) and PPAR-G in PRP-induced bone repair Giovanna Portela1 Emanuelle Cunha1 Juliana de Sousa Vieira1 João César Zielak1 Tatiana Miranda Deliberador1 Allan Fernando Giovanini1 Corresponding author: Giovanna Portela E-mail: giovanna_portela@hotmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: osteocalcin; PPAR gamma; platelet-rich plasma.

Introduction: The premise of PRP use is the rich source of growth factors involved in cell differentiation. Objective: Since bone marrow and bone are contiguous tissues, the aim of this study was to compare the ratio of osteocalcin (OC) and PPAR-g and compare them to the amount of adipose tissue and bone matrix deposited in the craniofacial repair induced by PRP. Material and methods: A 5 mm defect was prepared in 28 rat calvaria. One defect received autogenous bone (positive control), the other 100 uL of the PRP associated with 0.01 ml of autogenous bone. Presence of adipose tissue and bone matrix was evaluated by histomorphometric methods at 2 and 6 weeks postoperatively, while the presence of OC and PPAR-gamma was assessed by immunohistochemistry. Data were analyzed by Student-Newman-Keuls test (α = 5%) and all statistical comparison was done within the same period. Results: Results are always presented for periods of 2 and 6 weeks, respectively. The L-PRP group showed a ratio of OC / PPAR-g.

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Comparative study of vitamin E and C systemic action in alveolar bone remodeling of rats Caroline Resquetti Luppi1 Gustavo Jacobucci Farah1 Vinicius Denepotti Nogueira1 Carolina Luppi Gonçalves1 Roberto Kenji Nakamura Cuman1 Wilton Mitsunari Takeshita1 Corresponding author: Caroline Resquetti Luppi E-mail: carolineluppi123@gmail.com 1

Dentistry Course, Maringá State University – Maringá – PR – Brazil.

Keywords: bisphosphonates; osteonecrosis; free radicals.

Introduction: Vitamins are essential organic compounds for the normal functioning of the metabolism, with radioprotective and antioxidant action. Vitamin C (ascorbic acid) and vitamin E act as antioxidants intercepting and preventing the formation of free radicals that interfere with collagen production and subsequent bone remodeling. Objective: This study aimed to evaluate comparatively the systemic effect of vitamins on the alveolar bone healing after tooth extractions in rats. Material and methods: 15 rats were used (Rattus norvegicus albino Wistar strain), aged approximately 60 days, weighing between 200 and 300 grams, daily receiving 200mg / kg / day of vitamin C and E for 21 days from the surgical procedure.

The obtained bone specimens were analyzed by light microscopy to quantify the number of osteocytes. Results: The results found a significant difference between the control group, and groups vitamin C and vitamin E. Conclusion: Group vitamin E showed the best values, followed by group vitamin C, confirming the idea that vitamins favors greater bone repair.

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SEM analysis of dentaltitanium implants surface touched with surgical glove, steel tweezers, and titanium tweezers Rafael Peres1 Tatiana Miranda Deliberador1 João César Zielak1 Maria Cecília Giacomel1 Allan Fernando Giovanini1 Paulo Roberto Camati1 Corresponding author: Rafael Peres E-mail: rafaelkmh@msn.com 1

Dentistry Course, Positivo University – Curitiba –PR – Brazil.

Keywords: dental implant; scanning and transmission electron microscopy; titanium.

Introduction and Objective: To evaluate by scanning electron microscopy (SEM) whether the surface of dental titanium implants suffer damage by the touch with steel tweezers, titanium tweezers, and surgical glove. Material and methods: Twelve dental implants were divided into 4 groups: Titanium tweezers (TT): the surface of the dental implant was touched 4 times with light pressure by a sterilized tweezers; Steel tweezers (ST): the surface of the dental implant was touched 4 times with light pressure by a sterile steel tweezers; surgical glove (SG): the surface of the dental implant was touched 4 times with light pressure with sterile surgical glove; and control group (implants without touched the surface). Then dental implants were mounted in a metallic support (stub) with the aid of copper strips. It was not necessary to perform plating. The analyses and images (×50 to ×1.500) were performed by SEM (JSM-6360 LV, JEOL, Japan). Results: It was observed in groups TT, ST, SG a change on the surface of dental implants. Group TT showed a deformation in the touched area by leaving a flat and less rough surface. In group ST, the surface was crushed by leaving it smooth. In group SG, it was observed the presence of microparticles modifying the surface uniformity. Conclusion: The dental titanium implants are fragile to compression of different materials, which may modify and deform its surface.

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Case Report Studies

Aesthetic resolution of maxillary lateral incisor by implant immediate installation and prosthesis associated with lateral sliding flap

Carmen L. Mueller Storrer1 Sara Moncada S.1 Felipe Rychuv Santos1 João César Zielak1 Viviane Crivellaro1 Tatiana Miranda Deliberador1 Corresponding author: Carmen L. Mueller Storrer E-mail: carmen.storrer@gmail.com 1

Dentistry Course, Positivo University – Curitiba – PR – Brazil.

Keywords: dental implant; cosmetic dentistry; tissue graft.

Introduction: The installation of implants followed by tooth extraction of a single tooth is a common practice in Implantology.

This procedure is challenging in the aesthetic area. If the bone and gingival architecture of the tooth to be extracted is acceptable, the purpose of the implant will just keep the same morphological conditions. The installation of immediate temporary crown enables the maintenance of the surrounding gingival tissue and papillary height. The challenge, however, occurs when there is not enough gingival tissue to cover the implant fixed in the freshly extracted socket. Objective: This case report demonstrated the aesthetic and functional resolution of a maxillary lateral incisor with labial recession of 6 mm. Case report: A patient aged 56 years, healthy, former smoker, complained about the lack of aesthetics of tooth #22. At clinical examination, there was a 6mm recession with vertical root fracture. The other clinical periodontal parameters were normal. The proposed treatment was extraction of tooth #22. and immediate implant placement (Frictional I, Koop-Brazil) with immediate aesthetic. Due to the lack of labial bone autogenous bone was used, gathered from maxilla tuberosity, on the implant. To increase the gingival volume, subepithelial connective tissue graft and sliding flap was associated enabling the covering of the labial surface of the implant. Then the temporary crown was installed in infraocclusion. Conclusion: The aesthetic and functional resolution success of tooth replacement by implant in aesthetic region relies on the osseointegration knowledge and skill and on tissue manipulation by the surgeon.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):120

Correction of gingival smile without FLPA: predictability with minimum morbidity

Bernardo Born Passoni1 Bruna Corrêa1 João Gustavo Oliveira de Souza1 Armando Rodrigues Lopes Pereira Neto1 Ricardo de Souza Magini1 César Augusto Magalhães Benfatti1 Corresponding author: Bernardo Born Passoni E-mail: bpassoni@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: smile; cosmetic dentistry; surgical flaps.

Introduction: The harmonious relationship between the lips, gums and teeth composed an aesthetically acceptable smile. When not in harmony, the augmentation of the clinical crown can be an alternative for correcting / minimizing gingival smile, or cosmetic differences in the gingival margin. The usual technique is performed by lifting the flap to display the bone crest and posterior osteotomy, but there is also the possibility of gingival smile correction by flapless technique. Objective: To demonstrate and discuss the flapless technique for aesthetic increase of clinical crown. Case report: The surgery started by marking points for incision which was made according to the cemento-enamel junction (CEJ), which is identified by the explorer and measured by millimeter probe. After removal of the gingival tissue collar, the millimeter probe is used again to measure the distance from the gingival margin to the bone crest, which should ideally be 3mm. In areas where this distance is less than the recommended, osteotomy should be carried out via gingival sulcus, with the use of micro-chisels. To check the distance between the new gingival margin and the alveolar crest, a new probing was made. In the last step of the procedure, the improvement of the new margin contour is essential; for this, we use tissue cutting pliers.

Conclusion: The flapless surgical technique decreases tissue healing time, local inflammation, and thus the postoperative discomfort. In addition to promoting highly predictable aesthetic results.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):121

Step-by-step approach of extraction sockets in areas of pneumatized maxillary sinus

Bernardo Born Passoni1 João Gustavo Oliveira de Souza1 Armando Rodrigues Lopes Pereira Neto1 Antônio Carlos Cardoso1 Ricardo de Souza Magini1 César Augusto Magalhães Benfatti1 Corresponding author: Bernardo Born Passoni E-mail: bpassoni@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: bone regeneration; sinus; dental implants.

Introduction: The rehabilitation of the posterior atrophic maxilla bone requires a minimum bone amount for installation of dental implants, often impaired due to pneumatization of the maxillary sinus. Accordingly, often, bone grafting procedures are required.

For years, many techniques for such rehabilitation have appeared.

Objective: To demonstrate and discuss the possibility of cellular regeneration through Fugazzoto technique associated with autogenous graft and flap closure by Nemcovsky technique for later implant installation. Case report: First, an atraumatic extraction was performed. Then, with a trephine bur large enough to cover the entire inter-septum and about 50% of the extraction socket was used to prepare the site to approximately 2 mm from the maxillary sinus floor. Subsequently, we used an osteotome with diameter compatible with that of trephine bur, in order to raise the sinus f loor together with the septum. In addition, we performed the alveolar grafting with particulate autogenous bone. The alveolar closure was carried out using the technique described by Nemcovsky.

After 8 months of healing and bone maturation period, an external hexagon implant (3I) was installed, measuring 6.0x10.0mm, enabling Platform Switching. And after six months, the definitive implantsupported prosthesis was installed that has been in harmony with the peri-implant tissues for 1 year. Conclusion: It is possible, with great predictability, regenerate extraction sockets simultaneously to atraumatic augmentation of maxillary sinus through the association of unconventional techniques.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):122

Use of PDS II wire as titanium reinforced membrane substitute for guide bone regeneration techniques Bernardo Born Passoni1 Ricardo de Souza Magini1 César Augusto Magalhães Benfatti1 Corresponding author: Bernardo Born Passoni E-mail: bpassoni@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: bone regeneration; dental implants.

Introduction: The evolution of guided bone regeneration (GBR) has substantially influenced the possibilities for use of implants in sites not previously indicated. For years, a number of techniques for treating these bone defects have appeared traditionally made with resorbable or non resorbable membranes with titanium reinforcement.

Objective: To demonstrate and discuss a new GBR possibility around implants using arched polydioxanone wires (PDS II®). Case report: the extraction was atraumatically performed through two relaxing incisions and full thickness flap elevation; the extensive defect was noted in the buccal aspect. Then the implant and abutment installation was carried to wait osseointegration. Because many implant screws were exposed due to the defect on the buccal wall, it was decided to perform GBR through reconstruction technique using a scaffold with PDS wire. Four perforations were made on the bone (burs with diameter of 1mm), and within these holes, two x-shaped PDS wires were positioned This wire served as a base and prevented the collapse of the collagen membrane. To fill and cover the bone defect, we used a synthetic bone substitute (Bone Ceramic) and a collagen membrane. Conclusion: Although innovative, it is possible, with high predictability, to perform GBR with arched polydioxanone wire (PDS II®) in implants immediately placed. However, it is important to note that more studies are needed to elucidate the histological features of this proposed treatment.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):123

Optimization of immediate implant installation in inter-radicular septum area

Artur Breno Wanderley Alécio1 Letícia Moro Bins Ely1 Abraão Moratelli Prado1 José Daniel Suárez Rodríguez1 Aguedo Aragones1 Ricardo de Souza Magini1

Corresponding author: Artur Breno Wanderley Alécio E-mail: arturbrenow@gmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: implants; tooth extraction.

Introduction: To perform immediate implant installation in maxillary inter-septum area is a challenge, because during surgical preparation the alveolar septum may fracture and impair primary stabilization of the implant. Objective: To demonstrate through a case report, the surgical technique to optimize the immediate implant placement in maxillary inter-septum area. Case report: A female patient, aged 31 years was referred to the Clinics of the Teaching and Research Center in Dental Implants (CEPID) of the Federal University of Santa Catarina-UFSC, complaining of pain when chewing. The clinical examination revealed the presence of a mesial-distal fracture of tooth #16. CT scan showed that the fracture extended up to the furcation area. It was planned to perform the extraction followed by immediate implant installation. To optimize the immediate implant placement and to achieve primary stability, the odontosection comprised first the crown removal followed by the roots. With the help of a periotome, a slight dislocation of the roots was carried out. Then, we used bur sequence indicated by the manufacturer and with the roots still in position, we proceeded with removal of the roots and immediate installation 11 x 3.75 mm cone morse implant was obtained with primary stability of 45N, allowing the construction of the temporary crown. The post-extraction sockets were filled with particulate bovine graft in order to reduce the physiological remodeling. The preparation of the surgical socket with the roots in place prevents the inter-septum collapse and thus, increases the chances of obtaining primary stability.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):124

Peeri-implantitis surgical treatment Maurício Assunção Pereira1 Abraão Moratelli Prado1 Haline Renata Dalago1 Guenther Schuldt Filho1 José Moises de Souza Júnior1 Marco Aurélio Bianchini1 Corresponding author: Maurício Assunção Pereira E-mail: maurinto@gmail.com 1

Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: dental implants; periimplantitis.

Introduction: Peri-implantitis is present in 28-56% of patients and in 12-43% of the implants. It is characterized by the association of deep pockets, inflammation of mucosa and peri-implant bone loss. In general, the flora is similar to chronic periodontitis with predominance of gram-negative bacteria. The beneficial effects of chemical-mechanical biofilm removal and the treatment of periimplantitis demonstrate that the microorganisms are involved in the process. When there is no possibility of adequate access to the contaminated surface of the implants to perform non-surgical treatment, surgical treatment - using flaps and direct view - is the most appropriate and may involve: mechanical debridement of the implant surface, chemical decontamination, implantoplasty , bone grafting and soft tissue grafting. Objective: to present a case in which the surgical therapy was used for peri-implantitis treatment. Case report: A patient aged 45 years attended the Center for Teaching and Research in Dental Implants – CEPID / UFSC with inflammatory changes in peri-implant tissues of the implant in tooth #46 region.

After the diagnosis of peri-implantitis, the surgical treatment was performed through mechanical debridement of the implant surface, chemical decontamination with 3% citric acid for two minutes and implantoplasty. After a year, there was involution of peri-implant inflammation, absence of bleeding on probing and stabilization of bone loss. Conclusion: We conclude that surgical therapy may be effective in the treatment of peri-implantitis, but long-term monitoring is needed to ensure successful treatment.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):125

Dream to reality – metal-ceramic total rehabilitation of maxilla supported by implant Luciano Rosa1 Nereu Roque Dartora1 Paulo Renato Pulga1 Corresponding author: Luciano Rosa E-mail: lurosa78@hotmail.com 1

Odontocenter – Passo Fundo – RS – Brazil.

Keywords: dentistry; dental; dental implant.

Introduction: The implant-supported total rehabilitation of maxilla is an effective alternative when one seeks to achieve functional and aesthetic results. In addition to helping improve the masticatory and phonetic performance, the dream of a patient can become reality, “get back my teeth”. Objective: To present the clinical steps of a comprehensive implanted-supported rehabilitation of maxilla by metal-ceramic FPDs. Case report: A female patient aged 34 years, worn an acrylic denture, and with 12 pre-installed dental implants, sought for prosthetic rehabilitation. 12 mini-abutments were installed on the implants and transfer impression was performed to obtain the working cast. Then a test base was made with acrylic teeth to evaluate the aesthetic and functional criteria in mouth. From the professional and patient agreement, a wall-shaped silicon impression was executed to construct the infrastructure and completion of definitive prostheses. The metal-ceramic prostheses were fixed passively contributing to an excellent functional performance. Patient has been continuously followed-up. Conclusion: Implant-supported metal-ceramic fixed prostheses are a great alternative when seeking to meet the functional and aesthetic principles of full rehabilitation of maxilla. Thus, modern dentistry acts as a "fairy" able to turn dreams into reality.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):126

Atrophic mandible fracture after surgical rehabilitation with osseointegrated implants: case report Vinicius Fabris1 Jose Luiz Cintra Junqueira1 Agenor Montebello Filho1 Milena Bortolotto Felippe Silva1 Ariosto Ribeiro1 Corresponding author: Vinicius Fabris E-mail:vinifabris@hotmail.com 1

Dentistry Course, São Leopoldo Mandic – Campinas – SP – Brazil.

Keywords: atrophic mandible; mandibular fracture; dental implants.

Introduction: With the increase in life expectancy of the world population and advances in medicine and the pharmaceutical industry, more and more elderly patients have sought for oral rehabilitation, searching an improvement in masticatory function and quality of life.

Among these patients are the oral invalid, characterized by severe atrophy of the jaws, making impossible the conventional treatment by complete dentures. An alternative for these patients is the prosthetic rehabilitation associated with dental implants. It is indisputable that implant-supported total prosthesis (overdenture) brings a significant improvement in masticatory function, retention, stability, phonetics and hygiene supplying expectations of patients and professionals.

However, in elderly patients with atrophic jaws, the morphological changes are most striking, always occurring the fracture of the mandible. Objective and Case report: The aim of this study was to report a case of mandibular fracture with severe bone resorption resulting from the installation of overdenture supported by two implants the treatment of this fracture by means of rigid fixation and new rehabilitation with implants for making an implantedsupported fixed prosthesis to return the physiological and emotional functions of the patient. The treatment was successful without local complications. Conclusion: The clinical case was successful, but it is noteworthy that the prosthetic surgical planning for cases of mandibular severe atrophy should be thoroughly evaluated, mainly in rehabilitation choice, so that the prosthesis does not overload the remaining basal bone.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):127

Use of titanium miniplates as temporary skeletal anchorage in orthodontics Marcio Vinícius Hurczulack de Quadros1 Paulo Roberto Müller1 Corresponding author: Marcio Vinícius Hurczulack de Quadros E-mail: marciovhq@gmail.com 1

Dentistry Course, Federal University of Paraná – Curitiba – PR – Brazil.

Keywords: miniplates; procedures for orthodontic anchorage.

Introduction: The orthodontic skeletal anchorage systems are becoming increasingly versatile and allow the expansion of the possibilities of traditional orthodontic therapy. Fast, predictable and stable movements, applying continuous rather than intermittent forces, enable correction of some deformities that had previously been only possible through invasive orthognathic surgery. Objective: This study demonstrates the surgical procedure and the monitoring of the use of these systems through clinical cases and their outcomes.

Case report: Patients with maxilla-mandible deformities underwent orthodontic treatment requiring conventional surgery. The possibility of using miniplates for temporary anchorage was detected. The treatments were recorded at the pre-, trans- and post-surgery and are demonstrated through the following images. Results: Obtaining mechanical stability allows the application of active forces immediate to installation. There was virtually no damage to teeth of the patient, the movement did not depend on patient’s cooperation and the miniplates can be easily removed, being a minimally invasive procedure of lower cost in most cases. Conclusion: The correct indication and technique of application makes this treatment a real possibility of combined approach between the orthodontist and the oral and maxillofacial surgeon.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):128

Surgical approach of a lower third molar impacted and fused with a supernumerary adjacent to the canal mandibular: case report Marcio Vinícius Hurczulack de Quadros1 Arthur Berny Castellano1 Paulo Roberto Müller1 Corresponding author: Marcio Vinícius Hurczulack de Quadros E-mail: marciovhq@gmail.com 1

Dentistry Course, Federal University of Paraná – Curitiba – PR – Brazil.

Keywords: impacted tooth; supernumerary teeth; tooth abnormalities.

Introduction: The occurrence of mandibular supernumerary molar is rare (<2%). There are few reports in the literature of supernumerary teeth fused to the third molars. Its etiology is still unknown, but hypotheses of changes in the dental lamina cause germination of additional tooth are the most accepted. Objective: The following case is reported because it is considered an uncommon occurrence. Case report: The patient sought dental service of the Federal University of Paraná for surgical removal of third molars for orthodontic indication. The panoramic radiograph shows the presence of an adjacent tooth to tooth #38 compatible with fusion.

The radiolucency of dental apexes and disruption of upper cortical of the mandibular canal (MC) suggest its relation to the inferior alveolar nerve (IAN). CBCT confirmed the supernumerary contact with the interior of MC. The patient chose to undergo surgery under local anesthesia. It was necessary to perform a relaxing distal flap to access, buccal osteotomy and 2 buccal-lingual odontosections.

The tooth was removed in 3 fragments. The patient had no signs of INA paresthesia and recovered without complications. After surgical exploration, the hypothesis of dental fusion was confirmed also compatible with macrodontia of tooth 38. Conclusion: The management of teeth next to the MC requires accurate diagnostic imaging. This occurrence is rare, with few similar cases in the literature. Its surgical approach requires skill and precision to avoid damage to the IAN.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):129

Oral rehabilitation with single implants in aesthetic area: case report Gabriela de Souza Zimiani1 Eduardo Kurihara1 Roberto Masayuki Hayacibara1 Corresponding author: Gabriela de Souza Zimiani E-mail: gabrielazimiani@gmail.com 1

Dentistry Course, São Leopoldo Mandic – Campinas – SP – Brazil.

Keywords: oral rehabilitation; dental implants; cosmetic dentistry.

Introduction: The implant-supported rehabilitation has a high percentage of successful cases, both for the longevity of treatment and aesthetic and functional areas; however, this success is dependent on several factors. Among them are the inverse planning and proper evaluation of edentulous spaces, according to the amount of hard and soft tissues. Accordingly, the more the patient loses teeth, the harder it is planning, especially when it comes to cosmetic area of the jaw. Although rehabilitation with dental implants in this area is described in the literature, none of the analyzed papers addressed the viability of four individual cosmetic implants in the area of the incisor teeth. Objective: To report a rehabilitation treatment with four dental implants (Straumann® Bone-level) in the area of the upper incisors. Case report: A female patient, aged 51 years, presented the absence of teeth #12, #11, #21, and #22 and rehabilitation was performed with four individual implants in the edentulous area and the bone defect was corrected with autogenous bone graft, bone matrix inorganic bovine (Bio-oss®) and porcine collagen membrane (Bio Gide®). The surgery obtained aesthetic and satisfactory results.

Conclusion: The rehabilitation with four single implants in maxillary anterior region can be considered as an alternative treatment for patients with absence of the incisors, with aesthetic and functional satisfactory results, although this information is strictly limited.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):130

Partial resection of mandible with immediate installation of TMJ total prosthesis Bento Stang1 Jakson Pedro Antonelli1 Álvaro Bedin1 Alexandra Priester1 Fabiane Frigieri1 Lucely da Silva1 Corresponding author: Bento Stang E-mail: stang@unisep.edu.br 1

Dentistry Course, UNISEP-FEFB – PR – Brazil.

Keywords: TJM; mandible; graft.

Introduction: The mandibular resections are surgeries that cause sequels deforming the face, especially when TMJ resection is included in this procedure. The main indications for placement of condylar prosthesis are: degeneration of the joint, ankylosis and tumors involving TMJ. Objective: To present a case of partial reconstitution of the mandible with complete TMJ replacement. Case report: The case presented is of a young patient who after 8 years of previous diagnosis of an untreated lesion in the right mandibular angle searched the maxillofacial surgery service with upper swelling in right face. At clinical and radiographic examination, the presence of radiolucent tumor in right mandible was diagnosed already showing symptoms of facial asymmetry and local suppuration. It was planned a surgical treatment with use of rapid prototyping and custom fabrication of TMJ prosthesis after partial resection of the mandible. Conclusion: The diagnosis, planning and surgical treatment are benefited with the use of prototyping, which are obtained by a gain in the surgical procedure, better cosmetic result and immediate return to function.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):131

Bone expansion simultaneous to implant installation Gabriela Mercedes Juanito Peñarrieta1 Carolina Schaffer Morsch1 Caroline Freitas Rafael1 Juan Felipe Montero Dumez1 Luiz Fernando Gil1 Marco Aurélio Bianchini1 Corresponding author: Gabriela Mercedes Juanito Peñarrieta E-mail: gabriella.mpj@posgrad.ufsc.br 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: dental implants; bone resorption; devices for tissue expansion.

Introduction: Loss of bone volume after tooth extraction, due to bone resorption is a frequent situation in implant clinics. To solve this limitation, the surgeon has several treatment options from the need for more invasive surgical procedures such as previous bone grafts, to use narrow platform implants to rehabilitate the patient.

Objective: To report a minimally invasive surgical technique and simultaneous to implant installation thereby avoiding the need to perform a bone graft surgery using a manual bone expander. Case report: In this case the patient had bone thickness of 3mm which limited the use of a narrow platform implant. No intention of making a graft surgery, a bone expansion procedure was carried out by using the threaded expander (Implacil de Bortoli) to achieve an expansion that allowed the installation of an implant of 3.5mm in diameter. With a 1-year follow-up, it was observed an osseointegrated implant and in function. Conclusion: The choice for a less invasive technique for implant-supported rehabilitation whenever possible is a predictable and with considerable success rate technique.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):132

Clinical solution for correction of angledimplant without aesthetic impairment Caroline Freitas Rafael1 Cintia Schiochett1 Carolina Schaffer Morsch1 Camilo Villa Bona1 Claudia Ângela Maziero Volpato1 Antônio Carlos Cardoso1 Corresponding author: Caroline Freitas Rafael E-mail: carolfreitasrafael@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: dental implant; oral rehabilitation; dental prosthesis.

Introduction: Treatment with prosthetic implant has a high rate of success in the rehabilitation of missing elements. But a difficulty when working with intermediaries or abutments which do not allow customization of the collar is in relation to aesthetics, especially in thin periodontal tissue regions or implants placed by bone crest, which prevent their masking. The literature describes solutions for implants with correct three-dimensional positioning. However, in cases where it is necessary to correct the angle, few solutions have been described, making it necessary to resort to alternatives to correct the positioning of implants without sacrificing aesthetics. Objective: To use palatal implant screw to enable abutment masking, favoring the appearance and allowing the reversibility offered by a screwed prosthesis. Case report: In the clinical case described, we must remove the cemented prosthesis on the implant of the upper left first premolar region to be used as an abutment for the canine tooth, which was lost and did not have enough bone amounts for implant installation without additional surgery. The abutment used before was CeraOne with esthetic impairment. The proposed treatment was to replace the cemented prosthesis of the first premolar and use of a UCLA abutment to receive a screw by palatal surface. The patient was rehabilitated effectively with low cost and satisfactory cosmetic result. Conclusion: It was concluded that it is possible to use a UCLA abutment to receive palatal screw, so that treatment becomes more aesthetic, also allowing the reversibility because it is a screwed prosthesis.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):133

Rehabilitation of atrophic maxilla with prosthesis fixed on four implants: “all on four” Caroline Freitas Rafael1 Carolina Schaffer Morsch1 Gabriela Mercedes Juanito Peñarrieta1 Claudia Ângelo Maziero Volpato1 Marco Aurélio Bianchini1 Corresponding author: Caroline Freitas Rafael E-mail: carolfreitasrafael@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: dental implant; oral rehabilitation; dental prosthesis.

Introduction: The total prosthesis fixed on implant has a high success rate and is widespread. However, to be made, the standard protocol is the installation of four to six implants in the mandible, and six to eight in maxilla. The maxillary atrophy is common in total edentulous patients, which may preclude the use of larger amount of implants or require additional surgeries. Objective: To reduce surgical interventions and enable a fixed rehabilitation, the concept of “all on four” emerged, which is the use of only 4 implants without functional and mechanical impairment. Case report: Four external hexagon implants (Implacil De Bortoli, São Paulo, Brazil) were installed in the maxilla, with the posterior ones angled distally in order to reduce the “cantilever”. Because it is important that the last implants are the most distal possible, the maxillary sinus was identified and the implants placed tangent to the same. The remaining implants were distributed equidistant with the aid of a surgical guide previously manufactured. Postoperative and control radiographs were taken after six months. At the end, a predictable novel treatment was provided at a low cost, and reduced treatment time. Conclusion: By using less invasive procedures, the fixed rehabilitation was allowed even on atrophic maxilla, with low treatment time and cost.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):134

Vertical increase in anterior maxila through the nasal cavity augmentation by biooss and bioguide Caroline Freitas Rafael1 Clessius Ferreira Xavier1 Cintia Schiochett1 Carolina Schaffer Morsch1 Claudia Ângelo Maziero Volpato1 Marco Aurélio Bianchini1 Corresponding author: Caroline Freitas Rafael E-mail: carolfreitasrafael@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: oral rehabilitation; dental implant; dental.

Introduction: It is described in the literature the difficulty in obtaining vertical bone augmentation, either in the mandible or maxilla, which prevents or limits the rehabilitation with implants. In the anterior maxillary region, anatomical structures such as the nasal cavity and the palatine foramen may interfere with the planning of the case.

Objective: To surpass this limitation, a technique little described in the literature is the removal of the nasal cavity augmentation through the use of biomaterials. Case report: This case illustrates the surgical technique of detachment of the oronasal membrane and filled with lyophilized graft BioOss (Geistlich Pharma, Switzerland), with simultaneous installation of two implants Morse Taper (Implacil De Bortoli, São Paulo, Brazil) in region of lateral incisors and further cover of the region with BioGuide (Geistlich Pharma, Switzerland).

Pre and postoperative CT scans and control were carried out after six months in order to evaluate the increase in height which enabled the rehabilitation with implants even in a limiting region, with a reduced number of surgeries and a favorable long-term prognosis.

Conclusion: By using the technique of nasal cavity augmentation by use of biomaterials, it was possible to increase the vertical bony region of the lateral incisors.

ISSN: Electronic version: 1984-5685 RSBO. 2015 Jan-Mar;12(1):135

Space increase for rehabilitation in the anterior region through occlusal adjustment by addition Carolina Schaffer Morsch1 Caroline Freitas Rafael1 Leticia Bins Ely1 Gabriella Mercedes Juanito Peñarrieta1 Juan Felipe Montero Dumez1 Antônio Carlos Cardoso1 Corresponding author: Caroline Freitas Rafael E-mail: carolfreitasrafael@hotmail.com 1

Dentistry Course, Federal University of Santa Catarina – Florianópolis – SC – Brazil.

Keywords: occlusal adjustment; oral rehabilitation; dental occlusion.

Introduction: The lack of sufficient space for rehabilitation of anterior cases is a recurring limitation and requires knowledge of occlusion to be surpassed. The small space can be explained by the presence of parafunction and consequent tooth wear and loss of vertical occlusion dimension. To plan the treatment, the patient should be at centric relation to assess whether there is enough space for the restoration of anterior teeth. In cases where this space is large, the stabilization of the occlusion is made through occlusal adjustment by grinding, seeking the largest number of subsequent contacts, prioritizing the maintenance of the space in the anterior region. However, in some cases, this space is limited, preventing the occlusal adjustment by decreasing because 1 mm decreased in the posterior region will reduce 3 mm space in the anterior region. In these cases the recommended treatment is occlusal adjustment by addition, where the patient is at CR and this position is rehabilitated, with touch in the posterior region in premature contact, in the anterior region in rehabilitation, and in later contacts created through restorations or prostheses, distributed in a way to stabilize the occlusion. Objective: To rehabilitate the anterior region through adjustment by addition, the patient needs implant-supported prostheses in teeth #11 and #21 and fixed prostheses in teeth #24 and #22; however, when at maximum intercuspation enough space was not present. Case report: To plan the treatment, the patient was at CR and the presence of space was verified in the area to be rehabilitated, but this was not extensive.

To surpass this limitation, the technique of occlusal adjustment by addition was performed. The premature contact was in the tooth #17 and this contact was maintained. To stabilize the occlusion, teeth #14, #15, and #25 were restored with composite resin and provisional crowns of teeth #11 and #21 were made with thickness required for the completion of the work. The rehabilitation of the anterior region through adjustment by addition was satisfactory. Conclusion: With the use of occlusal adjustment technique by addition, it is possible to perform rehabilitation where there is limited space.