IAJD, 1, 2013

February 2013

ISSN 2218-0885

International Arab Journal of Dentistry ‫المجلة العربية الدولية لطب االسنان‬

Vol. 4 – Issue 1

Revue arabe internationale de dentisterie

Vol. 4 – Issue 1

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The International Arab Journal of Dentistry (IAJD) is a specialized, and refereed journal that is published quarterly in French and English.

IAJD is the official journal of the Society of Arab Dental Faculties (SARDF) and is published by the Faculty of Dental Medicine - Saint-Joseph University of Beirut.

UniversitĂŠ Saint-Joseph 2013 - International Arab Journal of Dentistry - www.iajd.org Society of Arab dental Faculties - www.sardf.org Published by Facuty of Dental Medicine, USJ All rights reserved Design and Layout by Alarm sarl, Beirut, Lebanon Printed and promoted by Dental News group, Beirut, Lebanon For any information concerning the IAJD, please contact us by e-mail :

info@iajd.org or fmd@usj.edu.lb

EDITORIAL AND SCIENTIFIC BOARDS Editorial board Editor Prof. Edgard NEHMÉ Faculty of Dental Medicine, Saint-Joseph University Lebanon

Officers Society of Arab Dental Faculties

Associate Editor Dr. Hiam WEHBÉ Faculty of Dental Medicine, Saint-Joseph University Lebanon

Prof. Maha Mahmoud ABDEL SALAM, Dean Faculty of Dental Medicine, University of Alexandria, Egypt

Assistant Editor Dr. Raëd LATTOUF Faculty of Dental Medicine, Saint-Joseph University Lebanon Editorial Advisory Board Prof. Nabih BADAWI Prof. Joseph BOUSERHAL Prof. Ass. Alfred NAAMAN Prof. Ass. Jeanine HOYEK GEBEILY Dr. Pascale HABRE HALLAGE

Prof. Nada BOU-ABBOUD NAAMAN, General Secretary, Dean Faculty of Dental Medicine, Saint-Joseph University, Lebanon

Prof. Elham ABU ALHAIJA, Dean Faculty of Dental Medicine, Jordan University of Science and technology, Jordan Prof. Jawad BEHBEHANI, Dean Faculty of Dental Medicine, Kuwait University, Kuwait Prof. Amal AL-WAZZANI, Dean Faculty of Dental Medicine, Hassan 2 University, Morocco Prof. Mohamed YOUSSEF, Dean Faculty of Dental Medicine, University of Damascus, Syria Prof. Antoine KHOURY, telltale & treasurer, Saint-Joseph University, Lebanon

Scientific reviewing board Dr. Khansa Ababneh, Jordan Prof. Nabil Abdel Fattah, Iraq Prof. Maha Abdel Salam, Egypt Prof. Elham Abu Alhaija, Jordan Prof. Salem Abu Fanas, UAE Prof. Hani Amin, Egypt Dr. Ola Al- Batayneh, Jordan Prof. Fouad Al-Belassi, Egypt Prof. Fahed Al-Harbi, KSA Prof. Abadi Al-Kadi, Egypt Dr. Qasem Al- Omari, Kuwait Prof. Abdallah Al-Shammari, KSA Prof. Khaled Al-Wazzan, KSA Prof. Amal Al-Wazzani, Maroc Prof. Athanasios Athanasiou, Greece Prof. Nabih Badawi, Lebanon Dr. Nayla Bassil- Nassif, Lebanon Prof. Jawad Behbehani, Kuwait Prof. Ass. Paul Boulos, Lebanon Prof. Joseph Bouserhal, Lebanon Dr. Diego Capri, Italy

Dr. Robert Cavézian, France Prof. Ass. Nada Chedid, Lebanon Dr. Maroun Dagher, Lebanon Dr. Maha Daou, Lebanon Prof. Azmi Darwazeh, Jordan Prof. Mounir Doumit, Lebanon Miss Lea El Korh, Lebanon Prof. Kifah El-Jemaani, Egypt Prof. Rabab el-Sabbagh, Syria Dr. Amine El Zoghbi, Lebanon Dr. Pascale Habre- Hallage, Lebanon Dr. Louis Hardan, Lebanon Prof. Raed moheiddine Helmi, Iraq Prof. Ass. Jeanine Hoyek Gebeily, Lebanon Prof. Mohammad Mazen Kabbani, Syria Prof. Imad Keaid, Syria Prof. Ass. Carlos Khairallah, Lebanon Prof. Razan Khattab, Syria Prof. Ammar Laïka, Syria Prof. Ass. Nada Mchayleh, Lebanon

Prof. Ahmed Medra, Egypt Prof. Raad Mehieddine Helmi, Iraq Dr. Nadim Mokbel, Lebanon Prof. Ass. Alfred Naaman, Lebanon Prof. Nada Naaman, Lebanon Prof. Essam Osman, Lebanon Prof. Lamia Oualha, Tunisia Prof. Hervé Reychler, Belgium Dr. Faouzi Riachi, Lebanon Prof. Sana Rida, Morocco Prof. Nouhad Rizk, Lebanon Prof. Joseph Sader, Lebanon Prof. Elizabeth Sarkis, Syria Dr. Bassel Tarkaji, Syria Prof. Georges Tawil, Lebanon Prof. Abed Yakan, Syria Prof. Nadia Ahmad Yehia, Sudan Dr. Ronald Younes, Lebanon Prof. Mohamed Youssef, Syria Prof. Ass. Carina Zogheib, Lebanon

EDITORIAL « C’est l’esprit qui mène le monde et non l’intelligence. » Antoine de Saint-Exupéry

Pr. Edgard Nehmé Editeur

Les dernières décennies du siècle passé avaient déjà préfiguré la spectaculaire révolution à l’échelle des moyens de communication, des outils, et par extension, celle de l’information de tous genres.

L’éblouissement des premiers moments s’est progressivement éclipsé devant les multiples problèmes, prévisibles d’ailleurs, qui ont émergé comme à chaque fois que les habitudes sociales, culturelles et comportementales sont brutalement bouleversées.

Rien qu’en portant un regard autour de nous sur les agissements et le comportement des individus, chacun dans son milieu naturel, force est de constater que bien des choses ont changé. Qu’il s’agisse du comportement au volant sur les autoroutes (de l’information ?), ou celui d’un simple piéton, d’un usager des réseaux publics, d’un étudiant en salle de cours ou d’un enseignant.

Que dire encore et encore des membres d’une même famille tranquillement (ou un peu trop) réunie en fin de journée, et dont les échanges de propos tournent autour des performances d’un téléphone mobile, d’une tablette et de je ne sais quel déballage grand public de photos fraichement prélevées sur Facebook et autres Picasa Web et Instagram.

Une violation intentionnelle de l’intimité qui frôle le voyeurisme, en diraient certaines âmes encore profanes !

Dans notre monde actuel la drogue n’est plus uniquement un « composé chimique, biochimique ou naturel, capable d’altérer une ou plusieurs activités neuronales et/ou de perturber les communications neuronales ». En fait, en plus de ces substances naturelles et des dérivés chimiques, il existe d’autres produits qui répondent aux caractéristiques d’une drogue, qui sont de pures créations de l’homme et font partie de notre environnement de tous les jours. Elles ont pour nom les Nouvelles Technologies de l’Information et de la Communication (NTIC). Nous constatons jour après jour que leur usage abusif les font rentrer dans le cadre des drogues avec évidemment leur cortège de conséquences néfastes en particulier sur la santé de leurs consommateurs. Sans oublier de mentionner que l’usage abusif d’une drogue appelle la dépendance et l’accoutumance.

Le téléphone portable, les SMS et la dérive de la langue, le langage et les techniques modernes de transmission, la perte progressive de l’écrit et de l’art de rédiger : des texto en plusieurs langues combinées qui ressemblent plus à un jeu de « chiffres et lettres », une orthographe lamentablement bafouée et livrée aux bons soins d’une pathétique auto-correction informatisée…

L’intoxication intellectuelle de masse est facilitée par un marketing de plus en plus professionnel.

Autant de symptômes révélateurs des dérives actuelles ou potentielles que nous promettent les avancées spectaculaires des technologies modernes.

Venons-en aux dangers et dérives.

Les NTIC ? Traduisez téléphone mobile, SMS, Internet, Facebook, Twitter, iPad etc. La meilleure et la pire des choses. Elles apportent des informations à profusion. Déjà en 2010, Cynthia Fleury, une jeune philosophe de l’Institut des sciences de la communication (ISCC-CNRS), rappelait que l’Internet était aussi une surveillance de tous les instants et la possibilité de diffuser des rumeurs. « Les nouvelles techniques de communication apportent l’instantanéité, l’interactivité. Elles permettent la création de nouveaux réseaux sociaux, ainsi que le mélange des savoirs, celui des experts et celui des profanes. Elles ont aussi leurs dangers et leurs dérives. On met en exergue la liberté, la gratuité... C’est faux. Vous payez un fournisseur d’accès. Et sur Internet, tout est régulé, contrôlé. Toute personne qui navigue sur la “toile” est épiée, tracée, profilée. Des ordinateurs enregistrent leurs coordonnées, leur âge, leurs goûts et tous les sites visités. Ces données sont ensuite vendues pour que vous receviez des publicités de plus en plus ciblées. » Sauf qu’il est possible pour un esprit libre et ouvert de réagir ! Des utilisateurs de Facebook, le plus fameux des réseaux sociaux, avaient menacé de se désabonner si le réseau continuait de diffuser des données personnelles sans leur autorisation. Facebook a reculé... « Il faut revendiquer ce droit à l’insurrection. Car si les internautes craignent que tous leurs propos soient lus, ils en viendront à se surveiller, à s’autocensurer. C’est la porte ouverte à la non-communication ! » A tous égards, l’enthousiasme de ceux qui voient dans Internet la porte du savoir, des informations illimitées, se doit de cultiver constamment la tempérance, de gérer proprement, de contrôler davantage. Cette profusion rend certes possible la consultation, la comparaison... en théorie ! Elle entraîne un effet de saturation, l’impossibilité du tri, l’absence de hiérarchisation.

Les moins initiés iront au plus facile, qui n’est pas obligatoirement l’information la plus importante ou la plus pertinente. Internet a un autre défaut : toute information peut être reproduite très vite, à des millions de personnes, sans avoir été soumise à la critique. Ce qui fait de la toile le paradis des rumeurs, des fausses nouvelles et une source néfaste de contagion.

Alors que les SMS et les courriels somment les individus de répondre en temps réel, sachons préserver le temps long. Un trésor oublié. Saurions-nous un jour mieux maîtriser nos pulsions et nos propres dérives pour faire bon usage de ce que nous offre la technologie et être capable d’exploiter à bon escient les outils dont on dispose.

EDITORIAL “It is the spirit that leads the world and not intelligence.”

Antoine de Saint-Exupéry

Pr. Edgard Nehmé Editor-in-chief

The last decades of the past century had already prefigured the spectacular revolution on the scale of media, tools, and by extension, information of all kinds.

The dazzling of the first moments gradually overshadowed in front of the many predictable problems which have emerged as each time that social, the cultural and behavioral habits are suddenly disrupted.

Simply by taking a look around us at the actions and behavior of individuals, each in his natural environment, it is clear that many things have changed. Whether driving behavior on highways (of information?), or that of a simple pedestrian, a user of public networks, a student in the classroom or a teacher.

What about that members of the same family quietly (or too much little) gathered at the end of the day, discussing about the performance of a mobile phone, a tablet, and freshly public photos freshly taken from Facebook and other Web Picasa and Instagram.

An intentional violation of privacy that borders on voyeurism, would argue some souls still profane!

In today’s world the drug is no longer just a “chemical, biochemical or natural compound, capable of altering one or more neural activities and / or disrupt neural communications.” In fact, in addition of these natural substances and chemical derivatives, there are other products that meet the characteristics of a drug, which are pure creations of man and are part of our everyday environment. They are named the New Technologies of Information and Communication (NTIC). We observe every day that their abuse make them go through their course of drugs with attendant negative consequences particularly on the health of their consumers. There is no need to mention that the misuse or drug abuse leads to dependency and addiction.

Mobile phone, SMS and the drift of the language, the language and techniques of modern transmission, the progressive loss of the writing and the art of drafting: the combined text message in several languages which look more like a game “numbers and letters” an orthography sadly trampled and delivered to the care of a pathetic self-correcting computer ... Intellectual mass poisoning is facilitated by a more professional marketing. All these symptoms are indicative of current or potential derivatives in which we are committed in conjunction with modern technological advances.

Let us come to the dangers and abuses.

NICTs? Translate mobile phone, SMS, Internet, Facebook, Twitter, iPad, ect. The best and worst. They provide information on abundance. Already in 2010, Cynthia Fleury, a young philosopher of the Institute of Science Communication (ISCC-CNRS), recalled that the Internet was also monitored at all times and the ability to spread rumors. “The new communication technologies bring immediacy, interactivity. They allow the creation of new social networks and the mixture of knowledge, the one of experts and the one of the laymen.

They also have their dangers and abuses. It emphasizes freedom, free ... This is false. You pay a provider. And on the Internet, everything is regulated, controlled. Anyone sailing on the Web is watched, drawn, profiled. Computers register their details, their age, tastes and sites visited in a way that you are exposed to receive the advertisements the more and more targeted.

Except that it is possible for a free and open to react! Facebook users, the most famous of social networks had threatened to unsubscribe if the network continued to broadcast personal data without their permission. Facebook declined ... “We must demand the right to insurrection. Because if users fear that their words will be read all, they come to monitor, censor themselves. This opens the door to non-communication!�

In all respects, the enthusiasm of those who see in Internet the door to knowledge, to abundant informations must be constantly tempered, properly managed, more controlled. This profusion certainly makes possible to refer, to compare ... in theory! It leads to a saturation effect, the impossibility of sorting and a lack of prioritization. Insiders at least will go to easier, which is not necessarily the most important information and the most relevant. Internet has another flaw: information may be reproduced very quickly, for millions of people, without having been subject to criticism. This makes the web a paradise of rumors, false news and a harmful source of contagion.

While SMS and emails summit individuals to respond in real time, let us preserve the time long.

A forgotten treasure. Would we know one day better control our impulses and our own excesses to make good use of what technology offers us and be able to use wisely the available tools.

SOMMAIRE | TABLE OF CONTENTS 9 9

ARTICLE SCIENTIFIQUE / SCIENTIFIC ARTICLE Endodontie / Endodontics The apical adaptation of different obturation techniques: an in vitro comparison of carrier-based systems with warm vertical compaction Mahmoud Rousan | Carla Zougheib

16

Dentisterie Restauratrice/ Restorative Dentistry Assessment of the nanoleakage between different adhesive systems and deproteinized dentin with Nd:YAG Laser and 10% NaOCL Raad Dayem

24 24

ARTICLE ORIGINAL / ORIGINAL ARTICLE Parodontologie / Periodontology A radiographic study of mandibular nutrient canals in patients with periodontal diseases Bhandarkar Gowri

32 32

CAS CLINIQUE / CASE REPORT Médecine Orale / Oral Medicine Malignant melanoma of the anterior mandibular gingiva Bhandarkar Gowri | Shetty Kushal

38

Pédodontie / Pedodontics Inducing apical barrier in fractured nonvital immature permanent incisors Mahsa Orooji | Rami Maksoud

42

CONGRÉS SCIENTIFIQUES INTERNATIONAUX 2013 SCIENTIFIC INTERNATIONAL MEETINGS 2013

ARTICLE SCIENTIFIQUE | SCIENTIFIC ARTICLE

Endodontie / Endodontics

THE APICAL ADAPTATION OF DIFFERENT OBTURATION TECHNIQUES: AN IN VITRO COMPARAISON OF CARRIER-BASED SYSTEMS WITH WARM VERTICAL COMPACTION Mahmoud Rousan* | Carla Zogheib-Moubarak**

Abstract

Résumé

The aim of study was to evaluate the apical adaptation of different obturation techniques by determining the amount of sealer in the apical third of the canal, the presence of obturator at the last one millimeter, the amount of gutta-percha and the presence of plastic carrier at the foramen. One hundred and eight freshly extracted single rooted teeth were divided into four groups: 1) group A: Warm Vertical Compaction “WVC” (VC), 27 teeth; 2) group B: Herofilll® obturators (HF), 27 teeth; 3) group C: Thermafil® obturators (TF), 27 teeth; 4) group D: RealSeal1® obturators (RS1), 27 teeth.

The results showed a significant difference between HF and VC when evaluating the amount of obturation material, the VC having a higher mean (p =0.0001) whereas no significant difference was detected between these two groups in terms of sealer mean area (p=0.268). On the other hand, RS1 showed a higher mean of obturation material (p=0.007) and a lower mean area of the plastic carrier (p=0.025) when compared to TF; these differences were at the 3mm section level. Both HF (p=0.030) and TF (p=0.039) groups had significantly less amount of sealer thickness only at 3mm section level compared to VC group.

RealSeal1® showed the most amount of obturation material and Herofill® showed the least.

L’étude vise à évaluer l’adaptation apicale de différentes techniques d’obturation en déterminant la quantité de ciment au niveau du tiers apical (derniers 5mm), la présence de l’obturateur au niveau du dernier millimètre apical, la quantité de guttapercha et la présence du tuteur en plastique au niveau du foramen. 108 dents monoradiculées fraîchement extraites ont été divisées en quatre groupes: 1) groupe A: compactage vertical à chaud «VC» (VC) (27 dents) ; 2) groupe B: obturateurs Herofill® (HF) (27 dents), 3) groupe C: obturateurs Thermafil® (TF) (27 dents), 4) groupe D: obturateurs RealSeal1® (RS1) (27 dents).

Les résultats ont montré une différence significative entre HF et VC, le VC présentant une moyenne plus élevée (p<0,0001) de la quantité du matériau d’obturation, alors qu’aucune différence significative n’a été décelée entre les deux groupes lorsque l’on a comparé la superficie moyenne du ciment (p = 0,268). D’autre part, RS1 a montré une moyenne plus élevée (p = 0,007) en termes de quantité du matériau d’obturation et une moyenne inférieure de la surface du tuteur en plastique (p = 0,025) par rapport à TF, ces différences étaient au niveau de la section de 3mm. Pour les deux groupes de HF (p = 0,030) et TF (p = 0,039), l’épaisseur du ciment était significativement moindre au niveau de la section de 3mm par rapport au groupe VC.

Keywords: Carrier-based systems - Thermafil® - Herofill® RealSeal1® - vertical compaction - leakage.

Mots-clés: Thermafil® - Herofill® - RealSeal1® - compactage vertical - ciment de scellement - technique d’obturation endodontique.

* Master in Endodontics Faculty of Dentistry, Saint- Joseph University of Beirut, Lebanon rousan_mahmoud1984@hotmail.com

** PhD, Maître de conférence, Dpt of Endodontics Faculty of Dental Medicine, Saint-Joseph University of Beirut, Lebanon

10

IAJD Vol. 4 – Issue 1

Article Scientifique | Scientific Article

Introduction Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage [1].

A number of obturation techniques have been introduced ranging from solid core filling of gutta-percha to softening techniques with either solvents or heat [2]. Flexible and plastic gutta-percha filling techniques have been developed in an attempt to find the best way to obliterate the entire root canal system in three dimensions.

Recently, resin bonding systems have been marketed to provide a better adhesion of the obturation material with the sealer and the dentine; this leads to the formation of a ‘monoblock’ that increases the resistance to fracture of the tooth [1, 3-5]. These systems, such as RealSeal® (Pentron Clinical Technologies, Wallingford, Connecticut, USA) and Epiphany® (Sybron Dental Specialities, Orange, California, USA), can be placed using lateral or warm vertical compaction or even thermoplastic injection.

Resilon™ material is a thermoplastic synthetic polymer-based root canal filling material. Based on polymers of polyester, Resilon™ contains bioactive glass and radiopaque fillers. It performs like gutta-percha, has the same handling properties, and for retreatment purposes may be softened with heat, or dissolved with solvents like chloroform.

The Thermafil® technique introduced

by Johnson in 1987 involves placing alpha phase gutta-percha on a metal carrier heating and using it to obturate the root canal. Currently used carriers are made of stainless steel, titanium or plastic.

Herofill® system (MicroMega) is a 3rd generation endodontic obturator developed to give the practitioner a

fast and reliable means of obturating a root canal, and is based on the principle of a solid plastic core coated with thermoplastic.

Literature regarding the carrier-based systems is scarce in general and is limited for the RealSeal1® system in particular.

The aim of this study is to compare the apical adaptation of different obturation techniques: Herofill®, Thermafil® and RealSeal 1® and WVC.

Materials and Methods 108 freshly extracted human teeth were collected from patients visiting the dental care units at the University of Saint Joseph, Beirut-Lebanon, the Jordanian Ministry of Health and two private clinics in Lebanon and Jordan.

Roots were flattened and given a length of 16mm. An ISO #10 K-file was introduced into canals to reach the apical foramen. The working length was established at 0.5mm short.

Roots were divided into four groups: Group A (27 roots): VC “Schilder technique”, MMseal® sealer.

Group B (27 roots): Herofill® obturation system, MMseal® sealer.

Group C (27 roots): Thermafil® obturators, AH Plus® sealer.

Group D (27 roots): Real Seal1® obturators system.

In groups A and B, ProTaper™ system was used to create a taper of 8%. The foramen diameter was set at 0.40mm by 2mm over instrumentation using the F2 file. In groups C and D, the Grater Taper (GT™, Dentsply, Tulsa Dental) rotary files were used to obtain the same calibers.

Root canals were prepared under copious irrigation with 5.25% NaOCl; one minute irrigation with 17% EDTA solution to ensure the removal of the smear layer was followed by 3ml irrigation with normal saline.

In group A, classical warm vertical compaction was applied and a #40 McSpadden gutta-percha condenser was used to backfill the coronal two thirds. In groups B, C and D, the roots

were filled with the carrier based systems according to the manufacturer’s instructions.

Once prepared, each root was embedded in light-cured resin (TechnoVit 7200), cured for 24 hours in a special light curing oven (Exakt 520, Exakt Technologies, Inc., Norderstedt, Germany) using a plastic conical carrier and then sectioned.

In groups B, C and D, the apical part of the roots was preserved for microscopic observation to detect the presence of the plastic obturator at the foramen level. Horizontal sections were obtained with a cutting system (Exakt 300) at the levels of the foramen, 1, 3 and 5 mm coronal to foramen. Sections were done using the lowest speed setting with continuous water cooling to prevent frictional heat and smearing of the filling material that may tend to mask the area of the sealer. All specimens were polished with sand papers mounted on a special rotary machine (Exakt 400 CS) on a pre-determined rotational speed to remove any debris as a result of sectioning excluding the foramen level section. All specimens were digitally photographed (Figs. 1- 4) under an optical microscope (Olympus CX41, Olympus, Japan). Images were then transferred to a computer. Computer software (AutoCad 2007) was used to measure the surface areas of the canals, the obturators, the sealer and the main obturation material (guttapercha or Resilon®).

Statistical analysis The statistical analysis was performed using a software program (SPSS for Windows, version 17.0, Chicago, IL, USA). The alpha error was set at 0.05.

Variables were tested for normal distribution using Kolmogorov-Smirnov test and for equality of variance using Levene test. One-way ANOVA followed

by Tukey post hoc comparisons tests were conducted to explore significant difference in mean between the four groups.

11 Endodontie / Endodontics

a

b

c

b

c

b

c

b

c

Fig. 1: Warm vertical compaction group sections (a) at 1mm, (b) at 3mm and (c) at 5mm.

a

Fig. 2: Herofill® group sections at (a) 1mm, (b) 3mm and (c) 5mm.

a

Fig. 3: Thermafil® group sections at (a) 1mm, (b) 3mm and (c) 5mm.

a

Fig. 4: RealSeal 1® group sections at (a) 1mm, (b) 3mm and (c) 5mm.

12

IAJD Vol. 4 – Issue 1

Article Scientifique | Scientific Article Parameter Group

Obturation material

Sealer

Plastic carrier

Mean area

S.D

Mean area

S.D

Mean area

S.D

HF

5.8512

3.4267

1.0985

1.5955

9.0409

3.7421

VC

15.6749

14.0608

1.3783

2.0438

-

-

p-values

0.0001*

0.682*

*Student t-test Table 1: Comparison of mean areas of obturation material and sealer between the HF and VC groups..

Parameter Group

HF

Obturation material

Sealer

Plastic carrier

Mean area

S.D

Mean area

S.D

Mean area

S.D

5.8512

3.4267

1.0985

1.5955

9.0409

3.7421

RS1

13.2393

5.8300

-

-

9.4001

3.6104

VC

15.6749

14.0608

1.3783

2.0438

-

-

TF

8.97764

5.5771

0.7583

1.6665

11.9845

P-values

0.000*

0.268*

4.5984

0.004*

*Student t test Table 2: Comparison of the mean areas of obturation material, sealer and plastic carrier between the RS1 and TF groups.

Results When comparing the mean areas of the obturation materials between VC and HF groups, statistically significant differences were detected between groups (p = 0.000) with the VC group having the highest mean (15.6749); this was consistent at all section levels.

When comparing the mean areas of the sealers used, no statistically significant differences were detected (p = 0.682) except at the 3mm section level (p = 0.001) with VC group having the highest mean (1.2852) as presented in table1.

When comparing the mean areas of the obturation materials in the groups TF and RS1, statistically significant differences were detected between the two groups (p = 0.007) with RS1 having the highest mean (13.2393); this was only

significant at the 3mm section level (p = 0.010). When comparing the mean area of the plastic carrier, statistically significant differences were detected (p = 0.025) with the RS1 group having the lowest mean (9.4001); this was only significant at the 1mm section level (p = 0.041) (Table2).

When evaluating the sealer mean area, no significant difference was found in all sections (p = 0.0268); however significance was detected at the 3mm section level (p = 0.011) with HF and TF having significantly less amount of sealer than VC (p = 0.030 and 0.039, respectively) (Fig. 6).

When comparing the mean areas of all the parameters in the four groups combined, statistically significant difference was detected in the mean area of obturation material (p=0.0001) with the VC having the highest mean; this difference was significant at all section levels (p=0.0001). At 1mm, RS1, VC and TF had significantly less amount of obturation material than HF (p =0.0001; 0.0001 and 0.004 respectively). At 3mm level, only HF and TF had less amount of obturation material than VC (p = 0.000 and 0.028, respectively) (Fig. 5).

For the plastic carrier mean area, HF had the lowest mean (p=0.004). This difference was observed at 1 and 3mm section levels (p = 0.026 and 0.023, respectively) as seen in table 3. At 1mm from the foramen, the only significant difference was detected between HF and TF (p = 0.030) with HF having significantly less mean area of plastic carrier. At 5mm, the only significant difference was between HF and TF (p = 0.021) (Fig. 7).

13 Endodontie / Endodontics

Fig. 5: Dense obturation material (gutta-percha).

Fig. 6: Sealer film showing between gutta percha and canal walls.

Fig. 7: Plastic carrier.

Parameter Group

Obturation material

Sealer

Plastic carrier

Mean area

S.D

Mean area

S.D

Mean area

S.D

RS1

13.2393

5.8300

-

-

9.4001

3.6104

TF

8.97764

5.5771

0.7583

1.6665

11.9845

4.5984

p-values

0.007*

0.025*

*One way ANOVA Table 3: Comparison of mean areas of obturation material, sealer and plastic carrier by group at different sections levels.

Discussion Complete obturation of the root canal system with an inert filling material and the creation of a hermetic, apical seal are considered the optimal goals for endodontic treatment [6]. Since the most common cause of endodontic failure has been attributed to incomplete obturation, many different obturation techniques have been developed in order to increase the success of root canal treatment.

All roots included in this study were prepared to an 8% taper and 0.40mm apical diameter with ProTaper™ and GT™ files systems. The 8% taper was selected to assure the best apical adaptation of obturation materials since it allows the flow of the obturation material into the canal system irregularities and ramifications. In a

recent study [7], the 8% taper showed the lowest percentage of voids in comparison to other tapers.

Gutta percha has been the material of choice for obturation since 1867.

There are a number of warm guttapercha methods. These carrier-based systems offer numerous potential advantages, mainly the ease of introduction of the obturation material into the canals’ irregularities, thus replicating the intricacies of the root canal system, especially in curved ones. In a study [8] comparing the Herofill® with thermo-mechanical gutta-percha compaction technique with a dye leakage methodology, the authors didn’t find any statistically significant difference. However, in our study, a higher mean of obturation material area was observed at the VC group compared to HF. This could be due to the absence of plastic carrier in the VC group. At the

3mm section level, statistically significant difference was detected with the HF having a higher mean area of sealer.

In this in vitro study, three carrierbased systems were compared to the warm vertical compaction technique.

Recent advances in obturation materials introduced resins into the filling materials, thus improving root canal adaptation of the filling to the canal walls [7].

Although sealers enhance sealing ability by filling in any residual spaces [9] and bonding to dentine [10] the optimal outcome in obturation is to maximize the volume of the core material and minimize the amount of sealer between the inert core and the canal wall [11, 12].

In their study, Weiss et al. [13] compared the average sealer cement film thickness and the extent and pat-

14

IAJD Vol. 4 – Issue 1

Article scientifique | Scientific Article

a

b

Fig. 8: (a) Massive amount of sealer and the central void; (b) Unsoftened cones.

tern of sealer penetration into dentinal tubules in association with four obturation techniques in curved root canals. Assuming that minimal sealer thickness and fewer voids are good measures of long-term sealing ability, Thermafil® resulted in the best outcome. SimpliFill® resulted in large sealer thicknesses and a high frequency of voids.

In our study, Thermafil® and Herofill® techniques showed the least amount of sealer at the 3mm section level.

The amount of obturation materials in all four groups was significantly different. The study of Gencoglu et al. [14] aimed to detect the apical leakage through a new computerized fluid filtration meter that allowed quantitative measurement of leakage easily.

They compared Thermafil®, Soft Core, JS Quick-fill, System B techniques, Microseal and lateral condensation; Thermafil® showed the least leakage among the four techniques without a statistically significant difference.

Even though in our study we adopted a different methodology to measure the apical adaptation of the 4 techniques, we found that the Thermafil® system showed a better apical adaptation especially when compared to the Herofill® technique.

The literature available concerning the RealSeal1® obturation system is lim-

ited as the system is relatively new.

When comparing RS1 to other carrierbased groups in terms of obturation material mean area, at 1mm section level, the RS1 group had significantly higher mean area than HF group but was similar to the TF group. No significant difference was detected with the VC group. At 3 and 5mm sections levels all carrier-based systems were similar as well as with the VC group.

When calculating the sealer mean area, the RS1 group was excluded since the differentiation between the sealer film and the obturation material was impossible due to the tight bond formed leading to the formation of a “monoblock”.

The use of heated gutta-percha allows better adaptation to dentinal walls and homogeneity of the filling material [15].

In the VC group, the back-filling of the coronal two thirds of the canals after the downpack was accomplished using a McSpadden gutta-percha condenser size 40. In 21 samples at the 5mm section level, this technique permitted to fill the space in an acceptable manner with a homogenous obturation; a thin layer of sealer was detected. In 6 samples, lack of homogeneity was observed (Fig. 8). In two of the 6 samples, the gutta-percha condenser left a relatively massive amount of sealer at the center of the canal with a small amount of gutta-percha pushed to one

of the walls; this could be explained by the extended rotational movement of the gutta-percha condenser in the canal that pushes the softened guttapercha out of it. In the other four samples, the backfilling cones were barely softened and at least one cone was left unsoftened leaving gaps between the cones and dentinal walls with a relatively large amount of sealer.

The detection of the plastic carrier tip directly at the foramen depends on the pressure applied by the operator during obturation; an excessive pressure might lead to shredding of the obturation material off the carrier leading.

Even though no statistically significant difference was observed among the groups, the tip of the plastic carrier was mostly detected at the foramen in the RS1 group (77% of the cases).

Conclusion Optimal filling of the root canals in three dimensions has paramount importance in prevention of the root canal reinfection.

Among the carrier-based systems themselves, Thermafil® obturation system showed the best outcome especially at the 1mm section level but it had the largest plastic carrier that reflected on the amount of gutta-percha. The RealSeal1® had the smallest plastic carrier and the largest amount of obturation material (Resilon®).

15 Endodontie / Endodontics HEROfill® obturation system showed a large amount of sealer especially at the most apical parts (1 and 3mm section levels) with a relatively large plastic carrier and with the least amount of obturation material at the most apical section.

The carrier-based techniques are reliable methods of obturation.

Nevertheless, it would be beneficial to conduct future research and add the new carrier-based system GuttaCore® (Dentsply Maillefer, Baillagues, Switzerland) to such line of research.

This new system consists of a crosslinked gutta-percha carrier instead of the traditional plastic carrier. On the other hand, Cone Beam-CT is an important new methodology and could be used in future studies. However, further in-vivo studies are beneficial in such line or research and should be considered.

References 1. Shanahan DJ and Duncan HF. Root canal filling using Resilon®: a review. Br Dent J 2011;211(2):81-8.

2. Schilder H. Filling root canals in three dimensions. 1967. J Endod 2006;32(4):281-90.

3. Stiegemeier D, Baumgartner JC, and J Ferracane. Comparison of push-out bond strengths of Resilon with three different sealers. J Endod 2010;36(2):318-21.

4. Lertchirakarn V, Poonkaew A, and Messer H. Fracture resistance of roots filled with gutta-percha or RealSeal®. Int Endod J 2011;44(11):1005-10.

5. Pameijer CH and Zmener O. Resin materials for root canal obturation. Dent Clin North Am 2010;54(2):325-44.

6. Nyguen NT. Obturation of the root canal system. In: Cohens S, Burns, RC, editors. Pathways of the pulp. 3rd ed. St. Louis: CV Mosby Co, 1984.

7. Zogheib C, Naaman A, Medioni E, Arbab-Chirani R. Influence of apical taper on the quality of thermoplasticized root fillings assessed by micro-computed tomography. Clin Oral Investig 2012 Oct;16(5):1493-8.

8. Boussetta F, Bal S, Romeas A, Boivin G, Magloire H, Farge P. In vitro evaluation of apical microleakage following canal filling with a coated carrier system compared with lateral and thermomechanical gutta-percha condensation techniques. Int Endod J 2003;36(5):367-71.

9. Hata G, Kawazoe S, Toda T, Weine F. Sealing ability of Thermafil® with and without sealer. J Endod 1992;18:322–6.

10. Najar AL, Saquy PC, Vansan LP, Sousa-Neto MD. Adhesion of a glass–ionomer root canal sealer to human dentine. Australian Endodontic Journal 2003;29:20–2.

11. Peters DD. Two-year in vitro solubility evaluation of four guttapercha sealer obturation techniques. J Endod 1986;12:139–45.

12. Wu M-K, Wesselink PR, Boersma J. A 1-year follow-up study on leakage of four root canal sealers at different thicknesses. Int Endod J 1995;28:185–9.

13. Weis MV, Parashos P, Messer H. Effect of obturation technique on sealer cement thickness and dentinal tubule penetration. Int Endod J 2004;37(10): 653-63.

14. Gencoglu N, Orucoglu H and Helvacioglu D. Apical leakage of different gutta-percha techniques: Thermafil®, Js Quick-Fill, Soft Core, Microseal, System B and Lateral Condensation with a computerized fluid filtration meter. Eur J Dent 2007;1(2): 97103.

15. De-Deus G, Reis C, Beznos D, et al. Limited ability of three commonly used thermoplasticized gutta-percha techniques in filling oval-shaped canals. J Endod, 2008;34(11):1401-5.

ARTICLE SCIENTIFIQUE | SCIENTIFIC ARTICLE

Dentisterie Restauratrice / Restorative Dentistry

ASSESSMENT OF THE NANOLEAKAGE BETWEEN DIFFERENT ADHESIVE SYSTEMS AND DEPROTEINIZED DENTIN WITH ND:YAG LASER AND 10%NAOCL Raad Dayem*

Abstract

Résumé

The objective of this study was to evaluate the global leakage scores on the interface between two adhesive systems and the acid-etched dentin and to estimate the nanoleakage after removing the collagen network by Nd:YAG laser or 10% NaOCl. Thirty extracted human upper premolars were selected to receive standardized buccal and lingual class V cavities. The teeth were randomly divided into two groups of fifteen teeth each: in the first group, the Excite® bonding system was used, whereas in the second group, the Solobond Plus adhesive system was applied.

In each group, teeth were equally allocated to one of the following treatments prior to bonding application: a) acid etching / Nd:YAG laser; b) acid etching /10% NaOCl and c) acid etching.

Global leakage score of each specimen was calculated as the percent of the total cut dentin surface penetrated by silver nitrate.

The results showed that treating the acid etched-dentin with Nd:YAG laser led to a significant decrease in the global leakage scores; these latter were significantly less than those of acidetched / 10% NaOCl treated dentin. The Excite® bonding system showed higher global leakage scores than the Solobond Plus bonding system.

Le but de cette étude était d’évaluer l’étanchéité du collage à l’interface entre deux types différents d’adhésifs dentaires et la dentine mordancée à l’acide; la déprotéinisation de la dentine a été réalisée au laser Nd:YAG ou par application de NaOCl à 10%.

Sur trente prémolaires supérieures, des cavités classe V standardisées ont été préparées au niveau des faces vestibulaires et linguales. Les dents ont été réparties au hasard en deux groupes de quinze dents chacun: le système « Excite® » a été utilisé pour le premier groupe et le système adhésif «Solobond Plus » pour le second. Dans chaque groupe, les dents ont été alloués à l’un des traitements suivants avant l’application de l’adhésif: a) mordançage à l’acide / laser Nd:YAG; b) mordançage à l’acide / NaOCl à 10% et c) mordançage à l’acide. Le score global d’infiltration a été calculé pour chaque dent. Les résultats ont montré que la déprotéinisation de la dentine mordancée à l’acide au laser Nd: YAG a entrainé une diminution significative des scores d’infiltration; ces derniers étaient significativement inférieurs à ceux de la dentine mordancée et déprotéinisée par le NaOCl à 10%. Le système adhésif Excite® a montré des scores d’infiltration plus élevés que le système de collage Solobond Plus.

Keywords: Nanoleakage - Nd: YAG laser – adhesive – acid etching.

Mots – clés : mordançage – adhésif - laser Nd:YAG.

* BDS, MSc, PhD Dean, Faculty of Dentistry, University of Duhok, Iraq raad_niama2003@yahoo.com

17 Dentisterie Restauratrice / Restorative dentistry

Introduction Dentin structure has been characterized as a biological composite of collagen matrix filled with submicron to nanometer-sized, calcium deficient, carbonate-rich apatite crystallites dispersed between parallel micron-sized hypermineralized, collagen poor, hollow cylinders (dentinal tubule containing peritubular dentin) [1] .

Hybridization of dentin is a process that creates a molecular level mixture of adhesive polymers and dental hard tissues [2]. Hybridized dentin is prepared in the subsurface of acid-etched tissues by the polymerization of resin monomers that have impregnated the tissues. It has a gradient structure because it is prepared by diffusion of monomers placed on the conditioned surface and their polymerization in situ.

Despite the significant improvements that have been made to adhesive systems, the bonded interface continues to remain the weakest point. Ideally, the adhesive would allow restorative material bio-integration and provide strong and durable bonds that would seal the tooth-restoration interface, preventing microleakage and the subsequent ingress of microorganisms [3, 4]. There are several explanations suggested for the bond failure namelyincomplete resin infiltration, the collapsed relatively impermeable region or a poor polymerization because of lack of sufficient irradiation [5].

The term “nanoleakage” has been introduced to explain a penetration pathway within hybrid layers of the dentincomposite junction in the absence of gap formation. This phenomenon is argued in the literature to be a risk factor for the quality of the dentin bonding [6].

Prior to the description of the phenomenon of nanoleakage in 1994, numerous studies on the quality of restoration margins were carried out [3]. The penetration depths were evaluated using conventional light microscopy.

However, the limited lateral resolu-

tion as well as the inadequate depth of focus did not allow detailed structure analysis within the hybrid layers. Such experiments should be conducted using higher lateral resolutions techniques than conventional light microscopy to differentiate between the various paths of penetrations [7].

A significant factor in achieving satisfactory adhesion of restorative resins to dentine substrate is the method by which the dentine surface is treated before an adhesive is applied. Removal of the collagen fibers with a deproteinizing agent would facilitate the access of the adhesive resins to a substrate that is more permeable and less sensitive to water content. Using deproteinization processes to remove the superficial destabilized collagen layer and subsurface remnants from etched dentine surfaces has been proposed since the 1990’s [8].

Sodium hypochlorite (NaOCl) is a nonspecific proteolytic agent that effectively removes organic components at room temperature. Literature shows that sodium hypochlorite treatment removes the dentine’s organic components and changes its chemical composition, so that it becomes similar to etched enamel. This substrate is also rich in exposed hydroxyapatite crystals and may result in a stable interface over time, because it is made of mineral. An increase in “wettability” is expected on deproteinized dentine surfaces, since they are hydrophilic [9] and are more permeable [10]. Thus, chemical interactions between resin and the deproteinized dentine surface are most likely to occur, since the surface has been described as having wider tubule openings with finer irregularities on the intertubular dentine, after treatment with a deproteinizing agent [8].

The neodymium: yttrium-aluminumgarnet (Nd:YAG) laser is an excellent surgical instrument for tissue coagulation, vaporization and incision. The Nd:YAG laser is attracted mostly to the pig-

mented tissue. The collagen network has the ability to be stained by special dye. So, if the dentin was acid-etched and the partially demineralized dentin was stained with special dye selective for collagen network, the Nd:YAG laser would ablate the collagen network selectively and deproteinize the dentin without affecting the mineralized tissue [11].

The objective of this study was to evaluate the global leakage scores on the interface between two adhesive systems and the acid-etched dentin and to estimate the nanoleakage after removing the collagen network by Nd:YAG laser or 10% NaOCl.

Materials and Methods Thirty sound human upper premolars were used in this study. Following extraction, they were cleaned and stored in 50% ethanol at 8°C for a maximum of 1 month in order to hinder bacterial growth. Prior to the experiments, the teeth were immersed in water for 24 hours at 20 °C [12].

Cavity preparation Standardized class V cavities were prepared on the buccal and lingual surfaces (3mm high, 3mm wide and 2mm depth) using a medium grain diamond bur # 848 on a high speed handpiece under water coolant. The outline of the cavity was drawn on the tooth surface with a 0.5 mechanical pencil using a matrix band with a pre-cut hole of 3mm x 3 mm; the matrix was fixed on the tooth with a retainer so that the gingival floor of the cavity was within the cemento-enamel junction.

The cavity form was completed with round bur #2, on a low speed handpiece under water coolant; the enamel margins were not beveled.

The teeth were randomly divided into two groups of fifteen teeth each; the Excite® (Ivoclar, Vivadent) and the Solobond Plus (VOCO GmbH) adhesive systems were applied in the first and the second groups, respectively.

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IAJD Vol. 4 – Issue 1

Article scientifique | Scientific Article Within each group, three modalities were adopted for teeth etching / demineralization prior to bonding application: a- Acid etching / Nd:YAG laser. b- Acid etching /10% NaOCl. c- Acid etching.

Conditioning of enamel and dentin The teeth were etched using the total etch technique (37% phosphoric acid); the etching was applied onto enamel and dentin beginning with the enamel margins for 15 seconds.

The cavities were thoroughly rinsed from phosphoric acid with water. The dentin surface was dried with an air syringe for two seconds to achieve a slightly moist surface with no visible excess water.

Treatment with Nd:YAG laser Van Gieson stain was prepared by mixing 1% of aqueous fuchsin solution (9 cm³) with saturated aqueous picric acid solution (50 cm³) and distilled water (50 cm³). A thin layer of Van Gieson stain was placed on the internal surfaces of the cavity using a Vivadent brush applicator; in a fine motion the dye was brushed gently onto the dentin. The teeth were stabilized in their positions on the laboratory manikin; this latter was fixed on the tray of the Nd:YAG device. The teeth were treated with Nd: YAG laser in a non-contact mode at its fundamental wavelength of 1064 nm, 10 mj, for three pulses with water cooling system [13].

NaOCl application The application of 10% NaOCl was done after acid etching using a disposable brush for a dwell time of one minute and the NaOCl was removed with 5 ml distilled water.

Application of the adhesive system and teeth restoration The Excite® or the Solobond Plus bond was applied onto the conditioned tooth structure. In a light motion the material was brushed gently for 10 seconds.

The bonding was left for 10 seconds, and the excess was removed with air stream free of water and oil. The bonding was light cured for 20 seconds.

The resin-based composite was applied in three incremental horizontal layers. Each layer was separately light cured for 20 seconds from all surfaces to ensure complete polymerization. Before curing the final increment, a transparent matrix was placed to contour the restoration. The margins were finished and polished with sandpaper disc.

Cavities per tooth were not interrelated. The data was analyzed as if they were independent replica cavities for each of the treatments.

The collected data was subjected to one-way ANOVA followed by Tukey post hoc comparisons test to explore significant difference in mean between the groups. The paired t-tests were used to compare the global leakage scores between each pair of groups of Excite bonding system and Solobond Plus bonding system. The alpha error was set at 0.05.

Ability to resist Nanoleakage The teeth were checked using a dissecting microscope to ensure that no flash was left along margins. Root apices were sealed with Tetric® Ceram (Ivoclar, Vivadent) composite and the entire teeth - except for the bonded interface and 1 mm of the teeth surface adjacent to the interface - were coated with two layers of nail varnish.

After that, the teeth were placed in a 50% (weight/volume) silver nitrate solution in total darkness for 24 hours, rinsed in running water for 5 minutes, immersed in photo-developing solution and exposed to a fluorescent light for 8 hours in order to reduce the silver ions to metallic silver [6]. After their removal from the developing solution, the teeth were placed under running water for 5 minutes and sectioned longitudinally across the bonded surface in order to obtain two sections of each sample. The sections were mounted on microscope glass slides using resin adhesive. All the cut surfaces were polished with increasing fine diamond pastes (3, 1 μm) obtaining a 4μ thickness sections and covered with slide covers. Examination was carried out using a polarized light microscope.

Global leakage score of each specimen was calculated as the percent of the total cut dentin surface penetrated by silver nitrate: Global leakage score =P/L x 100 where: P=length of silver nitrate penetration along the resin/dentin interface; L= total length of dentinal cavity wall on the cut surface [14].

Results All the samples in this study showed nanoleakage at the adhesive resin interface, but to a varying degree.

Figures 1 and 2 represent the means of the global leakage scores for the different groups and subgroups.

When the Nd:YAG laser was used after acid conditioning of the dentin, the polarized light microscopy showed the least amount of silver penetration; a very thin line or some few areas of silver deposition beneath the layer of Excite® bonding system was detected.

The mean of the global leakage scores were 5.8 ± 0.28.,.

When the 10% NaOCl was used after acid etching, the polarized light microscopy showed a relatively thick silver line with some tubules filled with silver deposition. The mean of the global leakage scores were 13.33 ±0.583.

When the dentin was not treated with any deproteinizing agent after acid conditioning, the polarized light microscopy showed thick areas of silver penetration involving the lower interface of the interdiffusion zone.

The mean of the global leakage scores were 31.17 ±0.76,.

The analysis of variance revealed a highly significant difference (p<0.001) in the global leakage scores among the three subgroups when using the Excite® adhesive system (Table 2).

19 Dentisterie Restauratrice / Restorative dentistry Scores

Groups

1

2

3

4

5

6

7

8

9

10

Mean

SD

Acid etching + Nd:YAG laser

6.2

6.1

6.2

5.5

5.7

5.8

5.4

5.7

5.8

5.6

5.8

±0.28

Acid etching + 10% NaOCl

12.4

13.5

12.9

12.8

12.9

13.7

13.5

13.3

14.1

14.2

13.33

±0.583

Acid etching

30.3

31.2

32.1

30.8

30.2

30.3

31.4

32.2

32

31.2

31.17

±0.76

Table 1: Mean and standard deviation values of the global leakage scores of each treatment modality for the Excite® bonding system.

Fig. 1: The means of the global leakage scores of each treatment for the Exite® bonding system (1a: acid etching / Nd:YAG laser / Exite®; 1b: acid etching /10% NaOCl / Exite® and 1c: acid etching / Exite®).

The Tukey’s multiple range test showed highly significant differences among all subgroups (Table 3).

Table 4: Mean and standard deviation values of the global leakage scores of each treatment for the Solobond Plus bonding system.

When the Nd:YAG laser was used after acid conditioning of the dentin, the polarized light microscopy showed the least amount of silver penetration; a very thin line or some few areas of silver deposition beneath the layer of Solobond plus bonding system was observed. The mean of the global leakage scores were 4.91% ± 0.35.

Fig. 2: The means of the global leakage scores of each treatment for the Solobond Plus bonding system (2a: acid etching / Nd:YAG laser / Solobond Plus; 2b: acid etching /10% NaOCl / Solobond Plus and 2c: acid etching / Solobond Plus).

When 10% NaOCl was used after acid conditioning of the dentin, the polarized light microscopy showed a relatively thick silver line with some tubules filled with silver deposition.

The mean of the global leakage scores were 10.7 ±0.46.

When the dentin was not treated with any deproteinizing agent after acid conditioning, the polarized light microscopy showed thick areas of silver penetration. The mean of the global leakage scores were 25.59 ±0.52 .

Table 5 shows the statistical analysis of the data using one-way ANOVA; a highly significant difference was found (p<0.001) in the global leakage scores among the three subgroups. The

Tukey’s multiple range test showed highly significant differences among all the subgroups when using the Solobond Plus adhesive system (Table 6).

Table 7 represents the paired t-test results of the global leakage scores when comparing each treatment modality using the Excite® and the Solobond Plus bonding systems. A highly significant difference was found between the corresponding treatments with higher scores obtained with the Excite® system (p<0.05).

Discussion The longevity of composite fillings depends, among other factors, on the

20

IAJD Vol. 4 – Issue 1

Article scientifique | Scientific Article Source of variance

Sum of Squares

df

Mean Squar

Between groups

3394.345

2

1697.672

Within groups

9.042

27

0.335

Total

3404.387

29

F

Sig

5069.36050

H.S

Table 2: Analysis of variance of global leakage scores of all treatments modalities for the Excite® bonding system.

Groups

Difference between means

Group 1a v/s 1b

7.53

Group 1a v/s 1c

25.37

Group 1b v/s 1c

17.84

HSD (5%)

HSD (1%)

Sig. H.S

0.642

0.823

H.S H.S

Table 3: The results of Tukey’s HSD test applied on the mean changes in values of the global leakage scores of each treatment modality using the Excite® bonding system.

creation of a hybrid layer and the interactions between the tooth substances and the filling materials.

Marginal discoloration, recurrent caries, postoperative sensitivity and the loss of restorations are the most frequent consequences of an insufficient or incorrect hybrid layer formation.

Many studies have been carried out to detect the amount of microleakage based on gap formation. Godoy and Finger [7] showed that with the restoration in place, the exact location of leakages cannot be detected in 75% of the cases.

To distinguish this type of leakage within the hybrid layer from the typical microleakage associated with gap formation, Sano et al. [14] introduced the term “nanoleakage”. Penetration pathways in nanoleakage are porosities of less than 50 nm located between the untreated dentin and the superficial collagen-rich fibrous network.

This nanoleakage may be the result of residual water around collagen fibrils, collapse of the collagen net-

work, or incomplete resin infiltration into exposed collagen network and polymerization [15]. Although the amount of nanoleakage may be very small (nanometer size) in the bonded assembly, over time, it has the potential to serve as a pathway for water movement within the adhesive-resin interface. Such water movement may extract unconverted monomers from the resin adhesive or hybrid layer.

Therefore, the effect of nanoleakage on the integrity of resin-dentin bonding has become an issue of interest, not only for short-term, but for long-term adhesion in particular [16]. The formation of nanoleakages within the hybrid layer and the adhesive-resin interface is an important indicator for judging the material’s sealing ability and for the quality of the hybrid layer, which, in turn, affects the longevity of the restoration [14].

In order to quantify the amount of nanoleakage, silver nitrate was used to visualize the depth of the dye penetration pathway within the hybrid layer

[14]. The silver nitrate staining is one of the most commonly used methods for microleakage evaluation at toothrestoration margins levels as it easily migrates within the interface zone due to its extremely small diameter molecule (0.059 nm) [17]. Moreover, silver nitrate induces an electron microscopic measurable contrast providing a sharp picture of the degree of penetration into the interface. Following its penetration, it has the potential to immobilize, which prevents further penetration during specimen preparation [18, 19]. Other organic dyes (including methylene blue and basic fuchsin) have been used for leakage evaluation, but these substances have larger molecules and exhibit a propensity for bonding to tooth structure that can potentially demonstrate a wider and deeper gap than actually exists.

Although the mechanisms leading to the nanoleakage phenomenon are not completely explored, our study showed nanoleakage at the adhesiveresin interface, to varying degrees; this

21 Dentisterie Restauratrice / Restorative dentistry Scores

Groups

1

2

3

4

5

6

7

8

9

10

Mean

SD

Acid etching + Nd:YAG laser

5.1

5.4

4.8

5.2

4.3

4.8

4.5

5.2

5.1

4.7

4.91

±0.35

Acid etching + 10% NaOCl

10.2

10.6

11.1

10.8

10

10.3

11.2

11.4

10.9

10.5

10.7

±0.46

Acid etching

25

25.4

24.8

24.7

25.1

25.2

25.5

26.2

10.9

26.1

25.59

±0.52

Table 4 : The mean values of the global leakage scores and the SD of the Solobond Plus bonding system after acid etching and deproteinization with Nd:YAG laser or 10% NaOCl application or without dentin deproteinization.

Source of variance

Sum of Squares

df

Mean Squar

Between groups

2331.129

2

1165.564

Within groups

136.642

27

5.061

Total

2194.487

29

F

Sig

230.312

H.S

Table 5: Analysis of variance of global leakage scores of the three treatment modalities using the Solobond Plus bonding system.

Groups

Difference between means

Group 2a v/s 2b

5.79

Group 2a v/s 2c

20.68

Group 2b v/s 2c

14.89

HSD (5%)

HSD (1%)

Sig. H.S

2.497

3.201

H.S H.S

Table 6: The results of Tukey’s HSD test applied on the mean changes in values of the global leakage scores of each treatment modality for the Solobond Plus bonding system.

Groups Acid etching + Nd:YAG Laser Acid etching + 10% NaOCl

Means Excite®

5.8

Solobond Plus

4.91

Excite®

13.33

Solobond Plus

10.7

Excite®

31.17

Solobond Plus

25.59

Acid etching

Table 7: Paired t-test of the global leakage scores to compare between each pair of groups for each treatment.

t-values

df

p- value

6.279

10

H.S

11.199

10

H.S

19.162

10

H.S

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IAJD Vol. 4 – Issue 1

Article scientifique | Scientific Article might be due, in part, to a discrepancy between the depth of etching and of resin penetration. Our results comply with those of Li et al. [20] who found that all the tested specimens showed nanoleakage at the adhesive-dentin interfaces, and with those of Sano et al. [14] who found that even in the absence of marginal gaps, there was a varying amount of penetration of the silver ions through the “hybrid layer” and into the underlying tubules.

Our results were also in agreement with those of Pioch et al. [21] who reported that dye penetration when using 1% rhodamin-B solution was observed in all specimens.

The application of Nd:YAG laser on conditioned dentin significantly decreases the values of the global leakage score regardless of the type of the dentin adhesive system [13]. This is due to the ability of Nd:YAG laser to remove the collagen network from the acid-etched dentin, thus increasing the diffusion potential of the monomer into the intact dentin and minimizing the nanoleakage.

The depletion of collagen from the surface of acid etched dentin results in: - an increase of the permeability of dentin substrate due to the dentinal tubules enlargement near the outer dentin surface; this will facilitate the spreading and diffusion of adhesive monomers through dentin (Barbosa et al. [22] and Inaba et al. [23]).

- an augmentation of the dentin surface energy and thus a potentialisation of the adhesive monomers diffusion through dentin (Bedran de Castro et al. [24]).

The proteolytic action of NaOCl is believed to involve extensive fragmentation of long peptide chains and formation of N-chloramines with terminal amine groups that further decompose to other by-products, including interand intra-molecular crosslinks via Schiff base formation [25, 26]. NaOCltreated dentin is rich in exposed hydroxyapatite crystals [26] and could result in a more stable interface over

time because it is essentially made of mineral [27]. In our study, the use of 10% NaOCl for one minute on the conditioned dentin had a decreasing effect on the global leakage scores. This result was in agreement with those of Pioch et al. [6]. Contrarily, Ferrari et al.

[28] found that the application of 10% NaOCl did not reduce the global leakage scores nor improve the restoration seal.

The lowest values of global leakage scores were recorded when using Solobond Plus, an acetone-based bonding system; Inai et al. [29] reported similar results due to the relatively high volatility of solvents such as acetone. In fact, alcohol may displace the surface moistures into the micro- or nanoporosities of the etched dentin surface.

Conclusion Within the limitations of this study, we found that treatment of the acidetched dentin with Nd:YAG laser led to a significant decrease in the leakage scores of the adhesive bonding system.

Nd:YAG laser can be therefore used for removing the collagen network from acid-etched dentin before applying the bonding agent to improve the quality of the dental restorations.

Also, better results were obtained with the application of 10% NaOCl after acid conditioning compared to acid conditioning alone.

The global leakage scores of Solobond Plus adhesive system were significantly less than those of the Excite® adhesive system.

23 Dentisterie Restauratrice / Restorative dentistry

References 1. Mjör IA. Pulp - dentin biology in restorative dentistry.

Quintessence Pub., 2002.

2. Nakabayashi N & Pashley DH. Hybridization of dental hard tissues. Quintessence Publ. 1998.

3. Alani AH, Toh CG. Detection of microleakage around dental restorations: a review. Oper Dent 1997:22:173-185.

4. Hekimoglu C, Anil N, Yakin EA. Microleakage study of ceramic laminate veneers by autoradiography: Effect of incisal edge preparation. J Oral Rehab 2004;31:265-270.

5. Spencer P, Wang Y, Walker MP, Wieliczka DM, Swafford JR. Interfacial chemistry of the dentin/adhesive bond. J Dent Res 2000;79:1458-1463.

6. Pioch T, Kobaslija S, Huseinbegovic A, Müller K, Dörfer CE. The effect of NaOCI Dentin treatment on nanoleakage formation. J Biomed Mat Res 2001;56: 578-83.

7. Garcia-Godoy F and Finger WJ. Reliability of microleakage evaluation using dentin bonding agents. J Dent Res 1993;72:308-315.

8. Wakabayashi Y, Kondou Y, Suzuki K, Yatani H, Yamashita A. Effect of dissolution of collagen on adhesion to dentine. Int J Prosthodont 1994;7:302–6.

9. Toledano M, Perdigao J, Osorio R, Osorio E. Effect of dentine deproteinization on microleakage of Class V composite restorations. Oper Dent 2000;25:497–504.

10. Prati C, Chersoni S, Pashley DH. Effect of removal of surface collagen fibrils on resin-dentine bonding. Dent Mater.

1999;15:323–31.

11. Franke M, Taylor AW, Lago A, Fredel MC. Influence of Nd:YAG laser irradiation on an adhesive restorative procedure. Oper Dent 2006;31(5):604-609.

12. Gwinnet AJ. Altered tissue contribution to interfacial bond strength with acid conditioned dentin. Am J Dent 1994;7:243246.

13. Dayem R. A novel method for removing the collagen network from acid-etched dentin by neodymium:yttrium-aluminumgarnet laser. J Lasers Med Sc 2009;24:93-99.

14. Sano H, Takatsu Ciucchi B, Horner JA, Matthews WG, Pashley DH. Nanoleakage: leakage within the hybrid layer. J Oper Dent1995;20:18-25.

15. Andia-Merlin RY, Garone-Netto N, Arana-Chavez VE. SEM evaluation of the interaction between a three-step adhesive and dentin. Oper Dent 2001;26:440–444.

16. Paul SJ, Welter DA, Ghazi M, Pashley D. Nanoleakage at the dentin adhesive interface vs. u-Tensile bond strength. Oper Dent 1999;24:181–188.

17. Ibarra G, Johnson GH, Geurtsen W, Vargas MA. Microleakage of porcelain veneer restorations bonded to enamel and dentin with a new self-adhesive resin-based dental cement. Dent Mater 2007;23:218–225.

18. Li H, Burrow MF, Tyas MJ. Nanoleakage patterns of four dentin bonding systems. Dent Mater 2000;16:48–56.

19. Pioch T, Staehle HJ, Duschner H, Garcia-Godoy F. Nanoleakage at the composite-dentin interface: A review. Am J Dent 2001;14:252–258.

20. Li H, Burrow MF, Tyas MJ. Nanoleakage patterns of four dentin bonding system. Dent Mater 2000;16: 48-56.

21. Pioch T, Staehle HJ, Wurst M, Duschner H, Dorfer. The nanoleakage phenomenon: Influence of moist vs. Dry bonding.

J Adhesive Dent 2000;4:23-30.

22. Barbosa K, Safavi KE, Spangberg SW. Influence of sodium hypochlorite on permeability and structure of cervical human dentin. Int Endod J 1994;27:309-12.

23. Inaba D, Lijima Y, Takagi O, Ruben J, Arends J. The influence of air-drying on hyper remineralization of demineralized dentin: A study on bulk as well as on thin wet section of bovine. J Caries Res 1995;29: 231-236.

24. Bedran de Castro AK, Hara AT, Pimenta LA. Influence of collagen removal on shear bond strength of one bottle adhesive systems in dentin. J Adhesive Dent 2000;2:271-277.

25. Mountouris G, Silikas N, Eliades G. Effect of sodium hypochlorite treatment on the molecular composition and morphology of human coronal dentin. J Adhes Dent 2004;6:175–82.

26. Erhardt MC, Osorio E, Aguilera FS, Proença JP, Osorio R, Toledano M. Influence of dentin acid-etching and NaOCltreatment on bond strengths of self-etch adhesives. Am J Dent 2008;21:44–8.

27. Toledano M, Perdigão J, Osorio E, Osorio R. Influence of NaOCl deproteinization on shear bond strength in function of dentin depth. Am J Dent 2002;15:252–5.

28. Ferrari M, Mason P, Vichi A, Davidson C. Role of hybridization on marginal leakage and bond strength. Am J Dent 2000;13: 329-336.

29. Inai N, Kanemura N, Tagami J, Watanabe LG, Marshall SJ, Marshal GW. Adhesion between collagen depleted dentin and adhesive. Am J Dent 1998; 1:123-127.

ARTICLE ORIGINAL | ORIGINAL ARTICLE

Parodontologie/ Periodontology

A RADIOGRAPHIC STUDY OF MANDIBULAR NUTRIENT CANALS IN PATIENTS WITH PERIODONTAL DISEASES Bhandarkar Gowri Pandarinath*

Abstract Nutrient canals are intra-osseous spaces or channels containing nerves and blood vessels. They are observed more frequently in the mandibular anterior region as radiolucent horizontal lines of varying widths, usually situated interproximally and inferiorly to the teeth. The aims of this investigation were to evaluate radiographically the presence of nutrient canals in 500 patients with periodontitis and 500 controls, to correlate their presence with severity of bone loss and trabecular bone pattern and to correlate the type of trabecular bone pattern to the age of the patient, bone loss and number of nutrient canals.

Keywords: Nutrient canals - periodontal bone loss - trabecular bone pattern.

Résumé Les canaux nourriciers sont des espaces ou des canaux intraosseux contenant les nerfs et les vaisseaux sanguins qui véhiculent les nutriments. Ils sont observés plus fréquemment dans la région antérieure mandibulaire sous forme de liserés, de largeurs variables, situés le plus souvent en situation interdentaire et inférieure aux dents. Ils ont une direction verticale plutôt qu’horizontale. Cette enquête a pour buts 1) d’évaluer radiologiquement la présence de ces canaux chez 500 patients atteints de parodontite et chez 500 sujets contrôles, 2) de corréler la présence de canaux nourriciers avec la gravité de la perte osseuse et le modèle d’os trabéculaire et 3) d’établir la corrélation entre le type d’os trabéculaire et l’âge du patient, la perte osseuse et le nombre de canaux nourriciers.

Mots-clés: canaux nourriciers - perte osseuse parodontale - os trabéculaire.

* MDS, Oral Medicine, Reader, A.J. Institute of Dental Sciences, Rajiv Gandhi, University of Health Sciences, India renuka.bhandari@rediffmail.com

Introduction Diagnostic radiography has evolved as an inseparable branch of dentistry. It is used primarily to detect dental caries, periapical and periodontal diseases.

Nutrient canals have been called interdental canals, circulating canals, vascular channels or interdental nutrient canals [1]. These are called the perforating canals of Zuckerkandl and Hirschfeld (nutrient canals), which house the interdental and interradicu-

lar arteries, veins, lymph vessels and nerves [2].

They are observed more frequently in the mandibular anterior region.

Nutrient canals may also be seen in other areas such as mandibular premolar area, maxillary premolar area and within the walls of the maxillary sinus [3].

On periapical x-rays, these canals appear as linear radiolucencies and vary in size, number, prominence and in their relationship to the dental roots [1].

Nutrient canals were frequently seen in

patients with thin alveolar ridges lacking trabecular spaces [4]. Others have correlated the radiographic appearance of nutrient canals with age, race and various pathogenic conditions such as periodontal disease, hypertension, diabetes, rickets, calcium deficiency, disuse atrophy and coarctation of the aorta [1].

The aims of this study were: 1- To evaluate radiographically the presence of nutrient canals in patients with periodontitis and in controls.

25 Parodontologie / Periodontology 2- To correlate the presence of nutrient canals with severity of bone loss and trabecular bone pattern.

3- To correlate the type of trabecular bone pattern to the age of the patient, the bone loss and the number of nutrient canals.

Material and Methods Selection Criteria 1000 subjects were selected for the study and were divided into a study and a control groups.

The study group patients were selected from Out-Patient Department of Oral Medicine, Diagnosis and Radiology of Bangalore Institute of Dental Sciences and consisted of 500 patients suffering from periodontitis. Patients with systemic diseases known to affect nutrient canals like diabetes mellitus, hypertension, rickets, coarctation of aorta [1, 5] were excluded.

The control group consisted of 500 individuals, free from periodontal or any systemic diseases known to affect nutrient canals. It consisted of volunteers like employees of the institution and the attendants who accompanied the patients to our Department.

The study group and the control group were divided into 4 groups according to their age as follows: Group I: 25-34 years.

Group II: 35-44 years.

Group III: 45-54 years.

Group IV: 55-64 years.

Ethical clearance was acquired from the Ethical Committee prior to the onset of the study and informed consent was also obtained from the participants.

Examination of the patients with periodontitis Each patient was examined under artificial illumination using mouth mirror, conventional probe and Williams graduated probe. Periodontitis was diagnosed in accordance with criteria adopted by the American Academy of Periodontology [6]. Clinical findings of gingival recession, tooth mobility

and probing pocket depth (PPD) were recorded as follows: Gingival recession (Millerâ&#x20AC;&#x2122;s classification [7]): Class I: The marginal tissue recession doesnâ&#x20AC;&#x2122;t extend up to the mucogingival junction. There is no loss of bone or of soft tissue in the interdental area. This type of recession can be narrow or wide.

Class II: The marginal tissue recession extends to or beyond the mucogingival junction. There is no loss of bone or of soft tissue in the interdental areas.

This type of recession can be subclassified into wide and narrow.

Class III: The marginal tissue recession extends to or beyond the mucogingival junction. There is interdental bone and/or soft tissue loss or there is malpositioning of the tooth.

Class IV: The marginal tissue recession extends to or beyond the mucogingival junction.

There is interdental bone and soft tissue loss and/or severe tooth malpositioning.

Periodontal pocket depth/ Clinical attachment loss (AAP, [6]): Slight: 1-2 mm of clinical attachment loss.

Moderate: 3-4 mm of clinical attachment loss.

Severe: 3-5 mm of clinical attachment loss.

Mobility [8]: -Class I: Tooth can be moved less than 1mm in the buccolingual or mesiodistal direction.

-Class II: Tooth can be moved 1mm or more in the buccolingual or mesiodistal direction.

No mobility in the occlusoapical direction (vertical mobility).

-Class III: Tooth can be moved 1mm or more in the buccolingual or mesiodistal direction.

Mobility in the occlusoapical direction is also present.

Radiographic technique The mandibular anterior region was selected as the site of study due to the higher frequency of occurrence of nutrient canals in this region [9]. The partially edentulous subjects were instructed to remove all removable prostheses from the mouth. The subject was then draped with a lead apron.

The film was removed from film dispenser and named according to the patientâ&#x20AC;&#x2122;s name and age. It was positioned straight behind the mandibular central incisors as close as possible to the lingual surface of teeth with apical end against lingual mucosa. The collimator of the x-ray unit was aligned in close approximation to the mandibular anterior teeth and centered to obtain the necessary vertical angulation. The intra-oral radiographs were taken using the no.2 Kodak Ektaspeed plus films. The exposure time was set at 0.3 seconds for mandibular anterior region. The intraoral bisecting angle technique was applied, with IOPAR machine (65 kVp; 10 mA).

Immediately after the exposure, the films were washed and dried. The exposed films were stored in a lightproof box with a lead lining and placed in the darkroom until they were processed.

All the films were processed manually in a well-equipped, light-proof dark room as described by White S.C. & Pharoah M.J. [10]. Each time, 30 films were taken for processing.

For processing the film, conventional developer and fixer available in the dark room were used. The developer and fixer solutions were stirred well. The hangers containing the films were immersed in the developer solution at the same time. Visual method of processing was adopted. The films were inspected for images and when the images were seen clearly, all the films were rinsed in running water for about 20 seconds. The hangers were then kept in the fixing solution for about 30 minutes. After that, the films

26

IAJD Vol. 4 – Issue 1

Article original|Original article

Fig. 1: Intra-oral periapical radiograph showing no bone loss (control group).

Fig. 2: Bone loss involving up to 1⁄3rd of root length also showing nutrient canals (white arrow).

Fig. 3: Bone loss involving up to 2⁄3rd of root length.

Fig. 4:Bone loss more than 2⁄3rd of root length.

Fig. 5: Above average – Greater radiopacity and diminutive medullary spaces.

Fig. 6: Average - Normal radiopacity and normal medullary spaces.

Fig. 7:Below average – Increased radiolucency, larger medullary spaces and thin individual less defined trabeculations.

27 Parodontologie / Periodontology

Sex

Control group

Study Group

Nutrient Canals

Nutrient Canals

Present

Absent

Total

Present

Absent

Total

Male

16 (7%)\*

213 (93%)

229

146 (49%)*

152 (51%)

298

Female

14 (5.2%) **

257 (94.8%)

271

98 (48.5%) **

104 (51.5%)

202

Total

30

470

500

244

256

500

Control versus study groups: In males: h² = 107.3; p<0.001.

In females: ȳ²= 120.3, p<0.001.

Table 1: Prevalence of nutrient canals according to patients’sex.

Age (Years)

Control group

Study Group

Nutrient Canals

Nutrient Canals

Present

Absent

Total

Present

Absent

Total

25 – 34

13 (5.8%)

228 (94.2%)

242

60 (40.3%)

89 (59.7%)

149

35 - 44

12 (7.9%)

151 (92.1%)

164

68 (46.9%)

77 (53.1%)

145

45 – 54

3 (4.5%)

64 (95.5%)

67

67 (53.2%)

59 (46.8%)

126

55 – 64

2 (7%)

25 (93%)

27

49 (61.3%)

31 (38.7%)

80

Total

30

470

500

244

256

500

h² = 15.6; p<0.05

h² = 21.6; p<0.01

Table 2: Prevalence of nutrient canals in control and study groups with reference to age groups.

were washed for about 30 minutes in running water and kept in dryer for 5 minutes. The dried films were placed in the respective covers. Likewise, all exposed films were processed.

Diagnostic assessment of radiographs Radiographic evaluation of nutrient canals was done by two interpreters in a room with subdued ambient illumination using an illuminated view box and a magnifying lens. The presence or absence of nutrient canals and the frequency (number) of nutrient canals was noted. Bone loss and trabecular bone pattern were also recorded. The alveolar bone loss was recorded according to the following (Figs. 1-3): 1. No bone loss.

2. Bone loss up to 1/3rd of the length of root.

3. Bone loss up to 2/3rd of the length of root.

4. Bone loss more than 2/3rd of the length of root.

The pattern of alveolar bone trabeculae were examined and recorded according to the following [11] (Figs. 5-7): 1. Above average: The radiopacity is greater than the average and the medullary spaces are obliterated.

2. Average: The radiopacity of the region is not extreme and the medullary spaces are relatively normal in size and shape.

3. Below average: The radiolucency of the area is increased, the medullary spaces are large and individual trabeculae are thin and less well defined.

Classification of trabecular space size was subjective; agreement between interpreters supported by photographs used for reference when doubt arose was the method used with no actual measurement of spaces being made.

Statistical analysis Chi square test was used for the statistical analysis. A significance of 5% or less was considered statistically significant.

Results With the criteria set for subject selection, the target number of subjects set for each group was achieved, i.e., 500 in each group. Among the 500 subjects of the control group, 229 were males and 271 were females; the mean age of males was 43 years and that of the females was 42 years old. Among the 500 patients with periodontitis, 298 were males and 202 were females; the mean age of males and females was 42 years and 43 years, respectively.

30 (6%) out of 500 subjects in the control group and 244 (48.8%) of the 500 chronic periodontitis patients

28

IAJD Vol. 4 – Issue 1

Article original|Original article Trabecular bone Pattern Age (Years)

Control group

Study Group

Above Average

Average

Below Average

Total

Above Average

Average

Below Average

Total

25-34

68 (28.0%)

117 (48.0%)

57 (24.0%)

242

69 (46.3%)

62 (41.6%)

18 (2.1%)

149

35-44

61 (36.6%)

67 (41.5%)

36 (21.9%)

164

88 (60.7%)

50 (34.5%)

7 (4.8%)

145

45-54

29 (43.3%)

31 (44.7%)

7 (12%)

67

76 (60.3%)

36 (28.6%)

14 (11.1%)

126

55-64

8 (29.6%)

13 (48.1%)

6 (22.2%)

27

59 (73.8%)

15 (18.7%)

6 (7.5%)

80

Total

166

228

106

500

292

163

45

500

h² = 15.6; p<0.05

h² = 21.6; p<0.01

Table 3: Relationship of trabecular bone pattern with reference to age.

Trabecular pattern Control group

Nutrient Canals

Study Group

Above Average

Average

Below Average

Total

Above average

Average

Below Average

Total

Present

19 (11.4%)

8 (3.5%)

3 (2.9%)

30

168 (57.5%)

56 (34.4%)

20 (44.4%)

244

Absent

147 (88.6%)

220 (96.5%)

103 (97.1%)

470

124 (42.5%)

107 (65.6%)

25 (55.6%)

256

Total

166

228

106

500

292

163

45

500

h² = 13.12; p<0.01

h² = 22.9; p<.001

Table 4: Relationship between trabecular bone pattern and nutrient canals.

revealed nutrient canals (l2 = 230.2; p<0.001).

In the study group, 49% of the males and 48.5% of the females showed nutrient canals. Differences in the presence of nutrient canals in males and females were not statistically significant; but when compared to the control group, it was statistically highly significant (7% and 5.2% in males and females, respectively) [Table 1].

Prevalence of nutrient canals was statistically higher in the age group of 55 – 64 years (61.3%) of the study group compared to the control group (Table 2). It was also higher in those with above average trabecular bone pattern i.e. 57.5% in study group and 11.4% in controls (statistically significant) [Table 3].

In controls, overall prevalence of 3 or more nutrient canals was 3 of 30 (6.6%) whereas in the study group, the prevalence was 61 of 244 (25%). However, the difference was not statistically significant.

The prevalence of above average trabecular bone pattern in patients with nutrient canals was higher in the study group (68.9%) than in controls (63.3%), even though the difference was not statistically significant). More specifically, in the 55-64 years age group, this prevalence of average trabecular bone pattern was 73.8% in the study group and 48.1% in the control group [Table 4].

Severity of bone loss of more than 2/3rd of root length was highest in the

age group of 55-64 years (31.2%) in the study group [Table 5].

The prevalence of nutrient canals increased as severity of bone loss increased (i.e. > 2/3rd root length).

In the study group, the frequency of nutrient canals of more than 3 increased (31.2%) when severity of bone loss was > 2/3rd of root length compared to only 21.3% when bone loss was amounting to <1/3rd of root length. This association was found to be significant [Table 6].

Nutrient canals were absent in 470 subjects of control and 256 subjects of study group.

In controls (i.e. no bone loss), there was higher prevalence of average

29 Parodontologie / Periodontology

Age (Years)

Control group

Study Group

No Bone Loss

Bone Loss

Total

< 1/3 n (%)

1/3 – 2/3 n (%)

>2/3 n (%)

Total n (%)

25-34

242

115 (77.2%)

22 (14.8%)

12 (8.1%)

149 (100%)

35-44

164

93 (64.1%)

32 (22%)

20 (13.9%)

145 (100%)

45-54

67

50 (39.7%)

52 (41.3%)

24 (19%)

126 (100%)

55-64

27

24 (30%)

31 (38.8%)

25 (31.2%)

80 (100%)

Total

500

282

137

81

500

h² = 70.3; p<0.001 Table 5: Relationship between age and bone loss.

Frequency of Nutrient Canals

Control group

Study Group

No Bone Loss

Bone Loss

Total

< 1/3 n (%)

1/3 – 2/3 (n (%)

>2/3 n (%)

Total

<3

28 (93.4%)

100 (78.7%)

50 (72.5%)

33 (68.8%)

183

³3

2 (6.6%)

27 (21.3%)

19 (27.5%)

15 (31.2%)

61

Total

30 (100%)

127 (100%)

69 (100%)

48 (100%)

244

h² = 130.4; p<0.001 Table 6: Relationship between bone loss and frequency of nutrient canals.

Trabecular bone pattern

Control

Study group

No Bone Loss

Bone Loss

Total

< 1/3

1/3 – 2/3

>2/3

Total

Above Average

166 (33.2%)

129 (45.7%)

91 (66.2%)

72 (88.9%)

292

Average

228 (45.8%)

120 (42.5%)

37 (27.3%)

6 (7.4%)

163

Below Average

106 (21%)

33 (11.8%)

9 (6.5%)

3 (3.7%)

45

Total

500

282

137

81

500

h² = 53.5; p<0.001

Table 7: Relationship between bone loss and trabecular bone pattern.

30

IAJD Vol. 4 â&#x20AC;&#x201C; Issue 1

Article original|Original article trabecular bone pattern (45.8%). In the study group, there was an increased prevalence of above average trabecular bone pattern as the severity of bone loss increased (i.e. > 2/3rd of root length) â&#x20AC;&#x201C; 72 of 81 (88.9%). This association was found to be statistically significant [Table 7].

Discussion Alteration of normal structure, either in bone or in soft tissue should be assessed when establishing a diagnosis.

This study based on the evaluation of the nutrient canals on radiographs of the anterior part of the mandible can be considered an elaborative study about the prevalence of theses canals in normal situations and their alterations in cases of pathologies. Nutrient canals are well visualized on intra-oral periapical radiographs, the standard x-rays in diagnosing and evaluating diseases of teeth and jaws. If established facts are available about the nutrient canals, it would be easy for any clinician to interpret the presence and the aspects of theses tube-likes canals because they might be considered a valid diagnostic marker for some specific systemic diseases.

In the present study, the relation between the periodontal disease and the prevalence and/or orientation of the nutrient canals was assessed. The pathologic entity was chosen because of the availability of patients and consequent cases, its relation with other systemic diseases and especially because it is considered one of the major causes of tooth loss.

Nutrient canals were observed in 6% of the individuals of the control group. This proportion is slightly low, compared to the results published by Ryder [4] (19.2%), Sweet [12] (15.8%), Lovette [13] (92%) and Patel and Wuehrmann [14] (42.5%). The difference in the results can be attributed to patient selection, since in the mentioned studies patients suffering from systemic conditions that might cause alterations in the bone anatomy and

especially in the nutrient canals morphology and/or visualisation were not excluded.

Nutrient canals were present in only 48.8% of the individuals suffering from periodontitis. This might be due to the variations in structural bone pattern and its physiological remodeling. Patel and Wuerhrmann [14] reported in their study that nutrient canals tend to be associated with advanced periodontal conditions. In our study, the incidence of nutrient canals increased in the advanced age (55-64 years) among chronic periodontitis patients. The development of new blood vessels with metabolic alteration of the bone might be related to the disease process and to the better visibility of nutrient canals with the sclerotic change in the trabecular bone [11].

Among the patients who have trabecular bone pattern of above average density, 57.5% had nutrient canals, those with average trabecular bone pattern, 34.4% had nutrient canals and those with below average trabecular bone pattern, 44.4% had nutrient canals.

This shows that the patients with above average trabecular bone pattern have more nutrient canals because of greater density of bone which results in better visibility of nutrient canals.

Conclusion The present study was undertaken to determine the prevalence of radiographic appearance of nutrient canals in controls and in patients with periodontitis.

It was shown that the prevalence of nutrient canals was higher in patients with periodontitis and in the age group 55-64 years.

Further studies must be conducted with large sample size to confirm that the configuration and the prevalence of nutrient canals are related with other disease processes. Thus, it is important to identify nutrient canals in routine intra-oral periapical radiographs as they serve as a diagnostic marker of various diseases, such as chronic periodontitis.

31 Parodontologie / Periodontology

References 1. Bilge OM and Harorli AB. Radiographic study of mandibular nutrient canal. Ann Dent, 1992;51:17-21 2. Bhaskar SN, Orban’s oral histology and embryology. 11th ed.

Harcourt Asia PTE Ltd., Mosby Year Book INC, 1999: 244 pp.

3. Worth HM. Principles and practice of oral radiographic interpretation. ed. Chicago: Year Book Medical Publishers, Inc, 1963: 41-2, 70 –1.

4. Ryder WB. The Significance of “Circulatory Canal” in roentgenograms of the alveolar process. Am. J. Orthod. Oral Surg. 1942;28:640-651.

5. Patni VM, Merchant GJ and Dhooria HS. Incidence of nutrient canals in hypertensive patients: A radiographic study. Oral Surg 1985;59:206-11.

6. Armitage G. Development of a classification system for periodontal diseases and conditions. Ann Periodontol 1999;4:1-6.

7. Miller P Jr. A classification of marginal tissue recession. Int J Perio Rest Dent 1985;5(2):9-13.

8. Carranza, FA: Clinical Diagnosis. In Newman, MG; Takei, HH; Carrana FA, editors: Carranza’s Clinical Periodontology, 9th Edition. Philadelphia: W.B. Saunders Company, 2002. page 439.

9. Stafne EC and Gibilisco JA. Oral radiographic diagnosis. 5th ed, Joseph A. Gibilisco: W. B. Saunders Co; 1985:3– 4.

10. White SC and Pharoah MJ. Oral radiology, Principles and interpretation. 5th ed. Mosby Elsevier Company, 2004:101-102, 184-5 pp.

11. Kishi K, Gotoh T and Fujiki Y. Radiographic study of mandibular nutrient canals. Oral Surg. 1982;54:118-22.

12. Sweet A. A statistical analysis of the incidence of nutrient channels and foramina in five hundred periapical full mouth radiodontic examinations. Am J Orthodont & Oral Surg. 1942;28: 427 70 -1.

13. Lovette DW. Nutrient canals: a roentgenographic study. JADA, 1948;37:671-5.

14. Patel JR and Wuehrmann AH. A radiographic study of nutrient canals. Oral Surg. 1976;42: 693-701.

CAS CLINIQUE | CASE REPORT

Médecine Orale / Oral Medicine

MALIGNANT MELANOMA OF THE ANTERIOR MANDIBULAR GINGIVA: A CASE REPORT Bhandarkar Gowri Pandarinath* | Shetty Kushal** Abstract

Résumé

Oral malignant melanoma is an infrequent neoplasm making up less than 1% of all melanomas; its behavior is more aggressive when compared to melanomas of the skin. We present a rare case of a 50-year-old male patient with a stage II oral malignant melanoma of the anterior mandibular gingiva treated with surgery and radiotherapy.

Le mélanome oral malin est une néoplasie rare représentant moins de 1% des mélanomes ; il présente un comportement beaucoup plus agressif que ceux de la peau. Nous présentons un cas rare de mélanome malin oral de la gencive mandibulaire antérieure chez un homme de 50 ans, traité par chirurgie et radiothérapie.

Keywords: Oral malignant melanoma - oral pigmentation mucosal melanoma.

* MDS, Oral Medicine, Reader, A.J. Institute of Dental Sciences, Rajiv Gandhi University of Health Sciences, India renuka.bhandari@rediffmail.com

Introduction Melanomas are malignant neoplasms arising from melanocytes, which originate from the neural crest cells and produce the melanin pigment of the epithelium’s basal layer. These neoplasms are grouped under the name of “Dispersed Neuro-Endocrine System (DNES) tumors”. Melanomas are present primarily in the basal portion of the epidermis at the dermal-epidermal junction [1].

Over 90% of melanomas occur on the skin with slightly more than 1% arising from mucosal surfaces [2]. The sites

Mots-clés: Mélanome oral malin - pigmentation orale - mélanome muqueux.

** MDS, Professor, Dpt of Pedodontics A.J. Institute of Dental Sciences, Rajiv Gandhi University of Health Sciences, India

of predilection for mucosal malignant melanomas are commonly the rectum and the vulvo-vaginal regions. In the head and neck region, nasal and paranasal melanomas are three times more common than oral malignant melanomas (OMM) [3]. These latter have a much poorer prognosis than those developing on the skin [4]. Primary OMMs are rare, representing 0.2–8% of all melanomas [5] and accounting for 0.5% of all oral malignancies [6].

Case report A 50-year-old male patient presented to our department with an asymptomatic pigmented lesion discovered on the mandibular gingiva nine months ago.

Initially the patient had noticed the change in the color of the vestibular gums. Three months later, he noticed a swelling in the same region and stated that the adjacent teeth had become mobile with the swelling gradually increasing in size.

Patient’s medical history was noncontributory. Thorough anamnesis and physical examination ruled out

33 Médecine Orale / Oral Medicine the possibility of melanotic lesions elsewhere in the body; the oral lesions were considered “primary”. On extraoral examination, submandibular lymphnodes were palpable on right and left sides. They were non-tender, about 1 cm in size, firm and freely mobile.

Intraoral examination showed a fungated, pigmented mass, measuring about 4×2.5cm on the labial gingiva extending to the lingual aspect of the anterior mandibular region (Fig. 1). It extended from the lower left lateral incisor region to that of the lower right canine, crossing the midline. Its surface was lobulated with a purplish-red discoloration of the overlying mucosa.

Its consistency was non-tender and firm.

The dental panoramic x-ray revealed soft tissue shadow of the mass with bone loss extending from the region of the lower left central incisor to the lower right premolar. There was also loss of the lamina dura in relation to the lower left anterior quadrant, with migration of the left lateral incisor laterally whereas the left central incisor exhibited a floating tooth appearance [Fig.2].

Considering the history, the clinical examination and the radiological findings, malignant melanoma was the provisional diagnosis. Differential diagnosis of Kaposi’s sarcoma, giant cell lesion and pyogenic granuloma were advocated. Based on clinical staging system for primary OMM, the present case was classified under stage II [7].

The routine blood and biochemical investigations were found to be within normal limits and the patient was nonreactive for HIV 1 and 2. Chest x-ray revealed no abnormality. Ultrasound of the abdomen ruled out liver metastasis. Incisional biopsy of the pigmented mass was done and histopathological findings were suggestive of malignant melanoma [Fig.3].

The surgical treatment consisted of marginal mandibulectomy and bilateral radical neck dissection.

Histopathological examinations of

the resected material showed malignant melanoma of the gingiva invading the mandibular bone. The patient was treated with radiotherapy to the tumoral and neck region. Patient is symptom-free for about a year now of follow-up.

Discussion Oral malignant melanoma is a rare aggressive neoplasm of the melanocytes, located along the tips and peripheries of the rete pegs. The ratio of melanocytes to keratinocytes in gingiva is 1:15 [3]. Melanocytes differ from nevus cells and melanoma cells in showing features of pleomorphism, hyperchromatism, prominent nucleoli and mitotic activity [3].

In contrast to cutaneous melanomas etiologically linked to sun exposure, mucosal melanomas can occur either owing to certain risk factors, like tobacco use and chronic irritation, or may be de novo [6]. Some may arise from pre-existing nevi, especially atypical (dysplastic) nevi, and congenital hairy nevi [8]. Genes implicated in the development of melanomas include CDKN2A (p16), CDK4 (chromosome 12q15), RB1, CDKN2A (p19) and PTEN/MMAC1 [9].

OMM generally affects in adults between 55 and 65 years of age [10] and more commonly among the Japanese with a male to female ratio of almost 2:1. It often occurs in the hard palate and the maxillary gingiva [11].

As the palate is continuously exposed to the air while breathing, irritants and carcinogenic compounds in the air (such as components of tobacco smoke) may play a contributing role in the development of melanomas [10]. It is interesting that among pigmented lesions of the oral cavity, oral nevomelanocytic nevi (OMNs) are localized mostly in the palate and this finding may lead to the hypothesis that subtypes of OMNs could be precursors of the pathogenesis of OMM [12]. Less commonly, melanomas also affect lips, buccal mucosa, mandibular gingiva,

tongue and floor of the mouth [4].

Our case report of OMM with respect to mandibular gingiva can therefore be regarded as a rare case seen in a male patient at the mandibular arch.

According to Tanaka et al. [13], oral melanomas could be classified into five types based on their clinical appearance: pigmented nodular, nonpigmented nodular, pigmented macular, pigmented mixed and non-pigmented mixed. The clinical coloration can appear as black, grey, purple or even reddish. The tumors are asymmetric, irregular in outline and occasionally multiple. Pain, ulceration and bleeding are rare until late stages of the disease. Lopez- Graniel et al.

[14] stated that haemorrhage was the most common presenting symptom.

Rolled borders are not a feature of oral mucosa melanoma because the atypical melanocytes exhibit a pagetoid mode of spread resulting in a uniform epithelial thickening [15]. No induration is observed which may be explained by the small, if not totally absent, inflammatory cell response at the lateral edges of the vertical growth phase [16]. In our case report, the patient presented with a pigmented, purplishred, non-tender and non-indurated mass.

Adjunctive radiologic diagnostic methods such as computed tomography, magnetic resonance imaging and positron emission tomography (staging purposes) are sometimes useful [7] and should be undertaken to explore regional metastases to the submandibular and cervical nodes.

Incisional biopsy is the method of choice for diagnosis [17].

An incisional biopsy was performed in our case, suggestive of OMM of the mandibular anterior gingiva.

Greene et al. [18] proposed three criteria for the diagnosis of primary OMM: 1) demonstration of malignant melanoma of the oral mucosa, 2) presence of so-called junctional activity (i.e. the melanocytes are arranged along the basal layer of the surface epithelium) in

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Cas clinique | Case report

Fig. 1: Pigmented mass on anterior mandibular gingiva.

Fig. 2: The orthopantomogram revealed loss of the lamina dura in relation to the lower anterior quadrant, with migration of 32 laterally; the 31 exhibited a ďŹ&#x201A;oating tooth appearance.

the lesion, and 3) the inability to show malignant melanoma in any other primary site. Based on these criteria, our case was diagnosed as primary OMM. Clinical staging system for primary oral melanoma with histopathological microstaging is as follows [7]: Stage I: Primary tumor present only (N0M0).

Level I: Pure in situ melanoma without evidence of invasion or in situ melanoma with microinvasion.

Level II: Invasion up to the lamina propria.

Level III: Deep tissue invasion into the skeletal muscle, bone or cartilage.

Stage II: Tumor metastatic to regional lymph nodes (T any N1M0).

Stage III: Tumor metastatic to distant sites (T any M1). Some authors reported a survival rate of 30% in tumors having a thickness of <5 mm, dropping to 18% in tumors with >5 mm thickness, and to 10% in patients with tumor thickness >1 cm [19]. Based on this, our case would belong to the group of patients having 10% survival rate as the tumor thickness is more than 1 cm.

The mainstay of treatment is wide surgical resection aiming at complete resection of the primary tumor and any positive cervical lymph nodes.

A sentinel lymphnode is the first lymphnode(s) to which cancer cells are most likely to spread from a primary tumor [20]. A sentinel lymphnode biopsy (SLNB) can be used to help deter-

mine the extent or stage of cancer in the body. Because SLNBs involve less extensive surgery and the removal of fewer lymph nodes than standard lymphnode surgery, the potential for adverse effects or harms is lower.

A negative SLNB result suggests that cancer has not acquired yet the ability to spread to nearby lymphnodes or other organs. A positive SLNB result indicates that cancer had reached the sentinel lymphnode and may be present in other nearby lymphnodes (called regional lymphnodes) and possibly, other organs. This information can help determining the stage of the cancer (extent of the disease within the body) and developing an appropriate treatment plan.

SLNBs may be done on an outpatient basis or may require a short stay in the hospital. In addition to helping doctors stage cancers and estimate the risk of spread to other parts of the body, SLNB may help some patients avoid more extensive lymphnode surgery.

Removing additional nearby lymph nodes to look for cancer cells may not be necessary if the sentinel node is negative for cancer. All lymphnode surgery can have adverse effects and some of these effects may be reduced or avoided if fewer lymphnodes are removed. The potential adverse effects of lymphnode surgery include the following: - Lymphedema or tissue swelling.

- Seroma or the buildup of lymph fluid at the site of the surgery.

- Numbness, tingling, or pain at the site of the surgery.

- Difficulty moving the affected body part.

SLNB like other surgical procedures can cause short-term pain, swelling, and bruising at the surgical site and can increase the risk of infection. In addition, some patients may have skin or allergic reactions to the blue dye used in SLNB. Another potential harm is a false-negative biopsy result which gives the patient and the doctor a false sense of security about the extent of cancer in the patientâ&#x20AC;&#x2122;s body.

Researchers have investigated whether patients with melanoma whose sentinel lymphnode is negative for cancer and who have no clinical signs of other lymph node involvement can also be spared more extensive lymphnode surgery at the time of primary tumor removal [20].

Sentinel-node biopsy or lymphoscintigraphy, beneficial in staging of cutaneous melanomas, has less value in staging or treating oral melanomas.

Complex and ambiguous drainage patterns may result in the bypass of some first-order nodes and in the occurrence of metastasis in contralateral nodes [21].

Amelanotic melanomas can resemble many different mesenchymal neoplasms, and immunohistochemical stains must be used for diagnosis. The

35 Médecine Orale / Oral Medicine

Fig. 3: Haematoxyllin and Eosin sections revealed numerous atypical melanocytes within the epithelium and invasion into the connective tissue. These cells are epitheloid to spindle in shape, with vesicular, hyperchromatic nuclei and prominent nucleoli.

pathologist should look for evidence of a lymphocytic reaction within the connective tissue and an increased number of melanocytes in the basal cell layer as an indication for immunohistochemical staining.

Leukocyte common antigen and Ki-1 are used to identify the lymphocytic lesions. Cytokeratin markers, often cocktails of high– and low–molecular-weight cytokeratins, can be used to help identifying epithelial malignancies.

The positivity to S-100 protein and homatropine methylbromide antigen (HMB-45) is characteristic of, although not specific for melanomas.

S-100 protein is frequently used to highlight the spindled, more neural-appearing melanocytes whereas HMB-45 is used to identify round cells.

Immunohistochemical tests revealed that there was intense and widespread positivity for NKFC3- associated melanoma antigens and focal positivity for vimentin and cytokeratin. Melanomas, unlike epithelial lesions, are identified by using vimentin, a marker of mesenchymal cells.

Microphthalmic-associated transcription factor (MITF), tyrosinase, and melanoma antigen (Melan-A) immunostains have been used to highlight melanocytes. The inclusion of these stains in a panel of stains for melanoma may be beneficial [2]. The use of at least 2 different immunostains is recommended for diagnosis.

MITF has value in decorating amelanotic melanomas and desmoplastic melanomas when other immunohistochemical stains have failed. S-100 protein and tyrosinase show the highest percentage of positivity. MART-1/ Melan-A is reported to be much more useful than HMB-45 for highlighting melanocytic tumors, but because it is a marker of melanocyte lineage, benign lesions such as melanocytic nevi also stain [21]. Reddy et al. in their case showed that special stains like Masson’s Fontana silver stain and Melanin Bleach technique are also helpful in the diagnosis of malignant melanoma for which they were positive [22].

Although melanoma is classically not radiosensitive, occasional patients have shown a good response to radia-

tion therapy. Immunotherapy has been successfully used but chemotherapy has demonstrated a relatively low response rate. Dacarbazine-DTIC, INF-a and INF-_-2b have been described as chemotherapeutical and immunotherapeutical treatments associated with Bacillus-Calmette-Guerin vaccine and recombinant interleukin-2 (rIL-2) in different combinations. Anecdotal reports describe success with IFN-_ or hyperfractionated radiation therapy. Many cancer centers follow surgical excision with a course of IL-2 as adjunctive therapy to prevent or limit recurrence. Peginterferon alpha-2b (Sylatron™) has been approved by the FDA for melanomas with microscopic or gross nodal involvement within 84 days of definitive surgical resection including complete lymphadenectomy.

Clinical trials of ipilimumab, a human monoclonal antibody, have shown encouraging results in therapy for metastatic melanoma. The drug blocks regulation of cytotoxic T-lymphocytes and allows sustained immunologic activity against melanomas and other malignancies. Ipilimumab body (Yervoy™) is now approved by the US

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IAJD Vol. 4 â&#x20AC;&#x201C; Issue 1

Cas clinique | Case report Food and Drug Administration (FDA) and is indicated for unresectable or metastatic melanomas [21].

The protocol of immunochemotherapy includes DTC (dimethyltriazeno-imidazole-carboxamide), ACNU (nimustine hydrochloride) and VCR (vincristine) which is also known as DAV protocol [23], coupled with OK-432 which is a biologic response modifier consisting of penicillin treated Streptococcus pyogenes and INF -_2.

Other immunotherapeutic drugs that are occasionally used include interferon and cimetidine, which, when used together, are believed to activate killer T cells and inhibit suppressor T cells, resulting in reduction of the size of the melanoma.

For patients with evidence of multiple positive lymphnodes or with extracapsular spread, post-operative radiation therapy after neck dissection seems to be appropriate [2]. In our case also, patient was treated by radiotherapy post-operatively. Radiation can also be used palliatively for metastatic disease [2]. Although radiation alone is reported to have questionable benefit (particularly in small fractionated doses), this therapy is a valuable adjuvant in achieving relapse-free survival when high-fractionated doses are used [21].

The melanoma-associated antigen (MAGE) family consists of a number of antigens initially recognized by cytotoxic T lymphocytes, which are currently being investigated for immunotherapy of patients with metastatic melanomas and other tumor types.

Expression of MAGE mRNA in melanocytic tumors is said to be restricted to invasive malignant tumors and absent in nevi. Recently, a monoclonal antibody (57B) has become available to examine MAGE protein expression in archival material. Because tumor-infiltrating lymphocytes in melanomas are associated with longer survival, their findings suggested a potential prognostic role for MAGE. Furthermore, the seeming restriction of immunopositivity to invasive malignant tumors

suggests a potential diagnostic role for the antibody 57B in confirming the malignant potential of a melanocytic tumor [24].

One reason for the poor prognosis of OMM is early invasion of the underlying tissue, increasing the likelihood of metastasis [13]. The five-year survival rate for OMM ranges from 9.4â&#x20AC;&#x201C; 15.6% even after radical treatment.

It depends on whether there is lymphnode involvement (18 months) or not (46 months) [6] and worsens with distant metastasis. The most common sites of metastasis are lymphnodes, liver and lung with widespread involvement occurring in severe cases.

Conclusion The present case emphasizes the importance of early diagnosis and management which could improve the survival rate in patients with OMM. In our case, one year survey speaks about and weighs little the importance of patient counseling. Educating and motivating the patients for follow-up play a very important role in increasing his/her life span and must be stressed upon to the patient.

Early identification of oral melanomas should be promoted by careful oral examination and early biopsy of pigmented and non-pigmented suspected masses since early diagnosis and intervention results in better prognosis [22].

37 Médecine Orale / Oral Medicine

References 1. Pandey M, Abraham EK, Mathew A, et al. Primary malignant melanoma of the upper aero- digestive tract. Int J Oral Maxillofac Surg. 1999;28:45–9.

2. Ebenezer J. Malignant melanoma of the oral cavity. Indian J Dent Res 2006;17:94-6.

3. Strauss JE, Strauss SI. Oral malignant melanoma: a case report and review of literature. J Oral Maxillofac 1994;52:972-6.

4. Garzino-Demo P, Fasolis M, Maggiore GMLT, et al. Oral mucosal melanoma: a series of case reports. J Craniomaxillofac Surg.

2004;32:251–7.

5. Hashemi MS. Malignant melanoma of the oral cavity: A review of literature. Indian J Dent Res 2008;19:47-51.

6. Meleti M, Leemans CR, Mooi WJ, et al. Oral malignant melanoma: a review of the literature. Oral Oncol. 2007;43:116– 21.

7. Prasad ML, Patel SG, Huvos AG, Shah JP, Busam KJ. Primary mucosal melanoma of the head and neck: A proposal for microstaging localized, Stage I (lymph node-negative) tumors.

Cancer 2004;100:1657-64.

8. Bork, Hoede, Korting, Burgdorf, Young. Diseases of the oral mucosa and the lips. Philadelphia: W.B. Saunders; 1996. p. 33640.

9. Rajendran R, Sivapada Sundaram B. Benign and Malignant tumors of the oral cavity. In: Shafer, Hine, Lavy, editors. Shafer’s Text book of oral pathology. India: Elsevier; 2009. p. 120-7.

10. Gorsky M, Epstein JB. Melanoma arisinig from the mucosal surfaces of the head and neck. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998;86:715–9.

11. Chidzonga MM, Mahomva L, Marimo C, et al. Primary malignant melanoma of the oral mucosa. J Oral Maxillofac Surg.

2007;65:1117–20.

12. Buchner A, Merrel PW, Carpenter WM. Relative frequency of solitary melanocytic lesions of the oral mucosa. J Oral Pathol Med. 2004;33: 550.

13. Tanaka M, Mimura M, Ogi, K, et al. Primary malignant melanoma of the oral cavity: Assessment and outcome from the clinical records of 35 patients. Int J Oral Maxillofac Surg. 2004;33:7615.

14. Lopez-Graniel CM, Ochoa-Carrilo FJ, Menese-Garcia A. Malignant melanoma of the oral cavity: diagnosis and treatment experience in a Mexican population. Oral Oncol.1999;35:425–30.

15. Manganaro AM, Hammond HL, Dalton MJ et al. Oral melanoma: Case reports and review of literature. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995;80:670.

16. Batsakis JG. Pathology of tumors of the oral cavity. In: Thawley SE, Panje WR, Batsakis JG et al(eds). Comprehensive management of head and neck tumors. Philadelphia: PA, Saunders; 1999:651-655.

17. Greenberg MS, Glic KM. Burket’s oral medicine. 9th ed. BC Decker: Hamilton; 2003;131-2, 214-5.

18. Greene GW, Haynes JW, Dozier M, Blumberg JM, Bernier JL. Primary malignant melanoma of the oral mucosa. Oral Surg Oral Med Oral Pathol 1953:6(12)1435-43.

19. Lourenno SV, A MS, Sotto MN, Bologna SB, Giacomo TB, Buim ME, et al. Primary oral mucosal melanoma: A series of 35 new cases from South America. Am J Dermatopathol. 2009;31:32330.

20. Sentinel Lymph Node Biopsy - National Cancer Institute. www. cancer.gov/ cancertopics/ sentinel-node-biopsy.

21. Collins II BM, Barnes Jr EL. Oral Malignant Melanoma. http:// www.misc.medscape.com.

22. Reddy BVR, Sridhar GR, Anuradha CH, Chandrasekhar P, Lingamaneni KP. Malignant melanoma of the mandibular gingiva: A rare occurrence. Indian J Dent Res. 2010; 21: 302305.

23. Rapidis AD, Apostolidis C, Vilos G and Valsamis S. Primary malignant melanoma of the oral mucosa. J Oral Maxillofac Surg.2003;61:1132-1139.

24. Busam KJ, Iversen K, Berwick M, Spagnoli GC, Old LJ, Jungbluth AA. Immunoreactivity with the anti-MAGE antibody 57B in malignant melanoma: Frequency of expression and correlation with prognostic parameters.Mod Pathol. 2000 Apr;13(4):45965.

CAS CLINIQUE | CASE REPORT

Epidémiologie/Epidemiology

Pédodontie / Pedodontics

INDUCING APICAL BARRIER IN FRACTURED NONVITAL IMMATURE PERMANENT INCISORS USING SINGLE CALCIUM HYDROXIDE DRESSING – A CASE REPORT Mahsa Orooji* | Rami Maksoud**

Abstract

Résumé

Endodontic treatment of immature traumatic non-vital permanent teeth is delicate since open apices and divergent canal walls render the debridement and obturation difficult. Its success depends on the closure of the root apex and the establishment of an apical barrier. Different materials are used for the apexification procedure. Calcium hydroxide apexification is the most common treatment for necrotic, immature permanent teeth. The aim of this report is to present a case of apexification using a single injected calcium hydroxide dressing for the treatment of a necrotic pulp of permanent incisors with wide open apexes in a young patient. The obtained result indicated that an apical stop is created with single visit apexification. Radiologic examination after 5 months showed that the apices of the maxillary incisors are completed by newly formed tissue. In spite of success in apical barrier formation by single visit calcium hydroxide dressing, long-term follow-up of these teeth is necessary.

Le traitement endodontique des dents permanentes immatures à la suite d’un trauma est délicat puisque les apex ouverts et la divergence des parois canalaires rendent le débridement et l’obturation difficiles. Son succès dépend de la création d’une constriction apicale. Différents matériaux sont utilisés pour la procédure d’apexification. L’apexification au moyen de l’hydroxyde de calcium est le traitement le plus répandu pour les dents permanentes immatures et/ou à pulpe nécrosée. L’objectif de ce rapport est de présenter un cas d’apexification réalisée en une seule séance à l’aide d’un hydroxyde de calcium injecté dans le cadre du traitement de la pulpe nécrosée des incisives permanentes immatures à apex largement ouverts chez une jeune patiente. L’examen radiologique à 5 mois a montré la fermeture complète des apex des incisives supérieures.

Mots-clés : Hydroxide de calcium – apexification – dent immature.

Keywords: Calcium hydroxide – apexification - apical closure - open apex - immature teeth.

* Postgraduate student, Dpt of Pediatric Dentistry Faculty of Dentistry University of Aleppo, Syria mahsaorooji@gmail.com

** Assistant professor, Dpt of Pediatric dentistry Faculty of dentistry, University of Aleppo, Syria maksouddds@hotmail.com

39 Pédodontie / Pedodontics

Introduction Dental traumatic injuries are very frequent among children and teenagers, especially in the range of 7 to 14 years old [1]. They may lead to tooth non-vitality. The anterior permanent incisors are usually the most affected teeth. When the apices are incompletely formed and the canals are wide, the endodontic treatment is often a major challenge because of the lack of apical constriction.

Apexification is the traditional technique to manage such cases; it is defined as “a method to induce a calcified barrier in a root with an open apex or the continued apical development of an incomplete root in teeth with necrotic pulp” [2].

Calcium hydroxide (Ca(OH)2) has been the material of choice for the apexification of immature permanent teeth [2, 3]. The time taken for complete apexification using calcium hydroxide has been reported to be variable, ranging from 5-20 months [3, 4] or 12.9 months as an average [5].

In this period, how frequently the calcium hydroxide dressing should be changed is a controversy in the endodontic literature. A report advocated changes at 1 month and at 6-8 months intervals until apical barrier formation [6]. Other studies have shown that replacing the dressing could be beneficial when calcium hydroxide is washed out of the canal [7].

This long course treatment has some challenges, like losing the temporary coronal restoration leading to re-infection [8], the risk of tooth fracture if the treatment is prolonged for extended periods [9, 10] and the need for many recall visits. Furthermore, this treatment requires a high level of patient compliance and the followup appointments to radiographically assess the barrier formation become critical.

For these reasons, a single-visit apexification using a single dressing with Ca(OH)2 has been suggested to

induce apical barrier formation in nonvital immature teeth [11- 13].

This case report describes the management of immature anterior incisors in a single visit, using Ca(OH)2 injected dressing to induce apexification.

Apexification was confirmed clinically by using paper point. At that time point, the canals were conventionally obturated with gutta percha (Fig.3) and a composite restauration in the access cavity.

Case report

Discussion

A 9-year-old girl presented to our department with a fractured permanent maxillary right and left central incisors. The patient fell while playing 6 months ago. The fracture in the permanent maxillary central incisors was evident on clinical examination. The pulp was necrotic since no response was obtained when applying vitality tests (cold and heat tests). The patient had mild pain on percussion. There was absence of any sinus tract.

Periapical radiography showed incomplete root formation with wide open apices (Fig. 1).

Both incisors were treated to induce apical development. In the first visit, an access cavity was prepared with high-speed round diamond bur under coolant. The necrotic pulp tissues in the chamber were removed with slow-speed round bur and the remained tissues in the canal were removed with broaches. The canal working length was determined with a K-file #30. Irrigation with 5% sodium hypochlorite was done throughout cleaning and shaping. The canal was dried using sterile absorbent paper points. After preparing the canal, a plastic needle was pushed down through the canal.

Then Ca(OH)2 Calcipex (Calcipex and Calcipex Plain; Nippon Shika Yakuhin KK, Shimonoseki, Japan) was injected into the canal during the pulling out process until the canal was completely filled (Fig. 2). The access cavity was temporarily obturated with Cavisol, an impermanent filling material that hardens when in contact with the saliva.

Periapical radiographs of both incisors showed continued apical development. At the recall visit 5 months later, the closure of the apex was evident on the radiograph.

Different materials have been used in the apexification of non-vital pulp in permanent teeth such as zinc oxide-iodoform [14], poly-antibiotic paste [15], antiseptic paste [16], calcium hydroxide based materials [17], Vitapex [18], or even no material at all [19].

The calcium hydroxide, introduced

by Hermann in 1930 [20], has been used with great success to induce the formation of an apical hard tissue barrier in immature open apices. Its biological characteristics and bacteriological effects are numerous. Calcium hydroxide has an antimicrobial effect [3] by releasing hydroxyl ions [21, 22] which cause protein denaturation and bacterial DNA damage. According to Sheehy and Roberts [23], the use of calcium hydroxide for apical barrier formation is successful in 74-100% of cases.

Kaiser [24] and Frank [25] were the first to use it and to report the reliable closure of immature roots. Because of its enhanced success rate, easy availability for clinician and affordability for patients, it has gained widest acceptance in the literature.

Chawla [12] has suggested that the amount of Ca(OH)2 in the single root canal dressing was sufficient to initiate and complete the bridge in 92.3% of the teeth in his study. Chosack et al. [26] suggested that repeated root filling are not required as Ca(OH)2 is only required to initiate healing process. They also reported that the Ca(OH)2 has to be replaced if there are any symptoms or displacement of the medicament.

The frequency of Ca(OH)2 dressing change is one of the few variables within the operator’s control, which also has an effect on the speed of bar-

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Cas clinique | Case report

Fig. 1: Incomplete root formation with wide open apices.

Fig. 2: Canals filled with Ca(OH)2.

Fig. 3: Periapical radiograph showing the apices formation.

rier formation. The time interval for calcium hydroxide apexification has been reported to be variable, ranging from 3-24 months [10]. Some studies showed that when the frequency of changes was low, rapid barrier formation was seen whereas when the frequency of the changes was high, it needed more time for barrier to be formed [27, 28]. Also it is confirmed that, if the apical barrier is disturbed by repeated instrumentation and dressing changes, the time needed for apex formation will be prolonged [29].

Calcipex is a calcium hydroxide waterbased paste for root canal dressing. It is easy to handle and the most easily removed. Its high radiopacity facilitates the radiological control during follow-up visits [30].

Patient compliance was not a concern in this study since an apical barrier was observed in a short period of 5 months and one single visit was necessary to achieve that.

References

Conclusion

10. Andreasen Joet al. Long-term calcium hydroxide as a root cannal dressing may increase the risk of root fracture. Dent Traumatol 2002 Jun;18 3:134-7.

The case described in this report showed that a single Ca(OH)2 dressing is enough to induce the apical barrier formation in immature teeth. However, this result can’t be generalized. Further studies on a larger sample with longterm follow- ups are necessary to prove the efficacy of this procedure.

1. Andreasen, J. O. & Ravn, J. J. Epidemiology of traumatic dental injury to primary and permanent teeth. Int. J. Oral Surg., 1:2359, 1972.

2. Kleier DJ, Barr ES. A study of endodontically apexified teeth.

Endod Dent Traumatol. 1991;7:112-7.

3. Rafter M : Apexification: A review. Dent Traumatol 2005;21:1-8.

4. Dominguez Reyes A. Munoz Munoz L, Aznar Martin T. Study of calcium hydroxide apexification in 26 young permanent incisors. Dent Traumatol 2005;21:141-5.

5. Ghose LJ, Baghdady VS, Hikmat M. Apexification of immature apices of pulpless permanent anterior teeth with calcium hydroxide. J Endod. 1987;13:285-90.

6. Cvek M. Treatment of non-vital permanent incisors with calcium hydroxide: I: Follow-up of periapical repair and apical closure of immature roots. Odontol Revy 1972;23:27-44.

7. Feiglin B. Differences in apex formation during apexification with calcium hydroxide paste. Endod Dent Traumatol 1985;1:195-9.

4.

8. Magura ME, Kafrawy AH, Brown CE Jr, Newton C. Human saliva coronal microleakage in obturated root canals: An in vitro study.

J Endod 1991;17: 324-31.

9. Andreasen JO, Munksgaard EC, Bakland LK. Comparison of fracture resistance in root canals of immature sheep teeth after filling with calcium hydroxide or MTA. Dent Traumatol 2006; 22:154-6.

11. Morse DR, O’Larnic J, Yesilsoy C. Apexification: review of the literature. Quintessence Int 1990; 21, 589-98.

12. Chawla HS. Apical closure in a nonvital permanent tooth using one Ca(OH)2 dressing. ASDC J Dent Child. 1986;53:44-7.

13. Vellore KG. Calcium hydroxide induced apical barrier in fractured nonvital immature permanent incisors. J Indian Soc Pedod Prev Dent 2010;28:110-2.

41 Pédodontie / Pedodontics 14. Cooke C, Rowbotham TC. Root canal therapy in non-vital teeth with open apices. Br Dent J 1960;108:147-50.

15. Ball JS. Apical root formation in nonvital immature permanent incisor. Report of a case. Br Dent J 1964;116:166-7.

16. Bouchon F. Apex formation following treatment of necrotized immature permanent incisor. J Dent Child 1966; 33:378-80.

17. Dylewski J. Apical closures of non-vital teeth. Oral Surg 1971;32:82-89.

18. Lu YM, Qin JN. A comparison of the effect between Vitapex paste and antibiotic paste in apexification. Shanghai Kou Qiang Yi Xue. 2004;13:449-51.

19. Chawla HS, Tewari A, Ramakrishnan E. A study of apexification without a catalyst paste. J Dent Child 1980;47:431-4.

20. Hermann BW. Dentinobliteration der wurzelkanale nach behandlung mit kalzium. Zahnarztl Rundschau 1930;39:888-90.

21. Estrela C, Pimento FC, Ito IY, et al. In vitro determination of direct antimicrobial effect of calcium hydroxide. J Endod 1988;24:15–7.

22. Jiang J, Zuo J, Chen SH, et al. Calcium hydroxide reduces lipopolysaccharide-stimulated osteoclast formation. Oral Surg 2003;95:348–54.

23. Sheehy EC, Roberts GJ. Use of calcium hydroxide for apical barrier formation and healing in non-vital immature permanent teeth: A review. Br Dent J. 1997 Oct 11;183 7:241-6.

24. Kaiser JH. Presentation to the American Association of Endodontists. Washington, DC, April, 1964.

25. Frank, AL. Therapy for divergent pulpless tooth by continued apical formation. J Am Dent Assoc 1966;72:87-931.

26. Chosack A, Sela J, Cleaton-Jones P. A histological and quantitative histomorphometric study of apexification of nonvital permanent incisors of vervet monkeys after repeated root filling with a calcium hydroxide paste. Endod Dent Traumatol. 1997; 13:211-7.

27. Vojinovi O. Induction of apical formation in immature teeth by different endodontic methods of treatment. Experimental pathohistological study. J Oral Rehabil. 1974;1:85-97.

28. De-Deus G, Coutinho-Filho T. The use of white Portland cement as an apical plug in a tooth with a necrotic pulp and wide-open apex: a case report. Int Endod J. 2007;40:653-60.

29. Kinirons MJ, Srinivasan V, Welbury RR, Finucane D. A study in two centers of variations in the time of apical barrier detection and barrier position in non-vital immature permanent incisors.

Int J Paediatr Dent. 200;11:447-51.

30. Leonardo MR, Hernandez ME, Silva LA, Tanomaru-Filho M. Effect of a calcium hydroxide–based root canal dressing on periapical repair in dogs: A histological study. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:680–685.

IAJD Vol. 4 – Issue 1

42

SCIENTIFIC INTERNATIONAL MEETINGS 2013

Africa countries Australia

CONGRÉS SCIENTIFIQUES INTERNATIONAUX 2013

Europe countries Far East countries Middle East & Arab countries North America countries South America countries

Event

Date

Location

Website

63rd Alpine Dental Conference

13-20 January

Courchevel, France

www.idfdentalconference.com

Dallas County Dental Society Southwest Dental Conference

17-19 January

Dallas, TX, USA

www.swdentalconf.org

Hawaii Dental Convention

24-25 January

Honolulu, Hawaii, USA

www.hawaiidentalassociation.net

Rocky Mountain Dental Convention 2013

24–26 January

Colorado, USA

www.rmdconline.com

Winnipeg, MB, Canada

www.manitobadentist.ca

Manitoba Dental Association - Annual Meeting & Convention

25-26 January

24th Saudi Dental Society International Dental Conference

28-30 January

KSA

www.sds.org.sa

38th Yankee Dental Congress 2013

30 January – 03 February

Boston, USA

www.yankeedental.com

CIOSP 31st Sao Paulo International Dental Meeting

31 January – 03 February

Sao Paulo, Brezil

www.ciosp.com.br

AEEDC Dubai 2013- The 17th edition of the UAE International Dental Conference & Arab Dental Exhibition

05–07 February

Dubai, UAE

www.index.ae

American Academy of Dental Group Practice – 41st Annual Conference & Exhibition

06-09 February

New Orleans, USA

www.aadgp.org

ITI Congress - France

07-09 February

Val d’Isère, France

www.iti.org

Academy of Laser Dentistry 2013 – 20th Annual Meeting

07-09 February

Palm Springs, USA

www.laserdentistry.org

66th Indian Dental Conference

10-13 February

Kolkata, India

www.ida.org.in

Imagina Dental 2013

21-23 February

Monaco

www.monacochannel.mc

Chicago Dental Society - Midwinter Meeting

21-23 February

Chicago, USA

www.cds.org

43 Mémento/Reminder

Event

Date

Location

Website

Oman International Dental Conference

27-28 February

Muscat, Oman

info@omanidc.com

18th Dental South China International Expo

27 February 02 March

Guangzhou, China

www.dentalsouthchina.com

The Dentistry Show 2013

01-02 March

Birmingham, England

www.thedentistryshow.co.uk

2013 Pacific Dental Conference

07-09 March

Vancouver, Canada

www.pdconf.com

Academy of Osseointegration (AO)28th Annual Meeting

07-09 March

Tampa, Florida, USA

www.osseo.org

The 81st Annual Nation’s Capital Dental Meeting

07-09 March

Washington, DC, USA

www.dcdental.org

Western Regional Dental Convention 2013

07-09 March

Arizona, USA

www.azda.org

35th International Dental Show (Biennial Meeting)

12-16 March

Cologne, Germany

www.ids-cologne.de

ITI Congress - Turkey

15-16 March

Ankara, Turkey

www.iti.org

ADEA 2013 American Dental Educational Association Annual Meeting

16-19 March

Washington, DC, USA

www.adea.org

American Dental Education Association (ADEA)

17–21 March

Seattle, USA

www.adea.org

American Association for Dental Research (AADR) – 42nd Annual Meeting and Exhibition

20–23 March

Seattle, USA

www.aadronline.org

Canadian Association for Dental Research (CADR)– 37th Annual Meeting

20–23 March

Seattle, USA

www.cadr-acrd.ca

ITI Congress - North America

04-06 April

Chicago, USA

www.iti.org

Scandefa 2013

11-13 April

Kopenhagen, Denmark

www.scandefa.dkGB

ITI Congress - Sweden

12-13 April

Stockholm, Sweden

www.iti.org

39th Annual Technorama

12-13 April

Canada

www.technoramadiac.ca

American Association of Endodontists - Annual Session

17-20 April

Honolulu, Hawaii, USA

www.aae.org

Special Care Dentistry Association – 25th Annual Meeting

18-21 April

New Orleans, Louisiana, USA

www.scdaonline.org

44

IAJD Vol. 4 – Issue 1

Mémento/Reminder

Event

Date

Location

Website

ITI Congress - Denmark

19 April

Nyborg, Denmark

www.iti.org

TI Congress - Benelux

19-20 April

Antwerp, Belgium

www.iti.org

National Oral Health Conference

22–24 April

Alabama, USA

www.nationaloralhealthconference. com

ITI Scientific Seminar

27 April

Bern, Switzerland

www.iti.org

2013 American Academy of Oral Medicine Annual Meeting

23-27 April

USA

www.aaom.com

American Academy of Cosmetic Dentistry - Annual Scientific Session

24-27 April

Seattle, WA, USA

www.aacd.com

Osteology

02–04 May

Monte Carlo, Monaco

www.osteology.org

Ontario Dental Association - Annual Spring Meeting

02-04 May

Toronto, Canada

www.oda.on.ca

American Association of Orthodontists - Annual Session

03-07 May

Philadelphia, PA, USA

www.aaomembers.org

35th Asia Pacific Dental Congress

07–12 May

Kuala Lumpur, Malaysia

www.mda.org.my

ITI Congress - China

09-10 May

Shanghai, China

www.iti.org

ITI Congress - South East Asia

16-17 May

Bangkok, Thailand

www.iti.org

Dental Expo 2013

17–18 May

Auckland, New Zealand

www.dentalexpo.co.nz

American Academy of Pediatric Dentistry– 66th Annual Session

23–26 May

Orlando, USA

www.aapd.org

9th World Endodontic Congress (IFEA)

23-26 May

Tokyo, Japan

www2.convention.co.jp

Annual Convention of the Ordre des dentistes du Quebec

24-28 May

Montreal, Canada

www.odq.qc.ca

Salon Dental Chile

30 May – 01 June

Santiago de Chile

www.salondentalchile.cl

International Association of Paediatric Dentistry (IAPD)

12–15 June

Seoul, Korea

www.iapdworld.org

ITI Congress - Argentina & Uruguay

14-15 June

Buenos Aires, Argentina

www.iti.org

American Dental Hygienists’ Association (ADHA) – 90th Annual Session

19–25 June

Boston, USA

www.adha.org

45 Mémento/Reminder

Event

Date

Location

Website

American Dental Society of Europe – 119th Annual Meeting

20–22 June

Dijon, Burgundy, France

www.ads-eu.org

ITI Congress Austria

21–22 June

Salzburg, Austria

www.iti.org

American Dental Hygienists’ Association - Annual Session

21–22 June

Boston, Massachusetts, USA

www.adha.org

Academy of General Dentistry Annual Meeting & Exhibits

27-30 June

Nashville, Tennessee, USA

www.agd.org

European Organisation for Caries Research – 60th ORCA Congress

3–6 July

Liverpool, United Kingdom

www.orca-caries-research.org

ITI Congress - Australasia

26-27 July

Sydney, Australia

www.iti.org

ITI Congress - Southern Africa

26-27 July

Johannesburg, South Africa

www.iti.org

International Federation of Dental Hygienist – 19th International Symposium on Dental Hygiene

14–17 August

Cape Town, South Africa

www.ifdh.org

ITI Congress Italy

27-28 September

Venice, Italy

www.iti.org

FDI Annual World Dental Congress

29 August - 01 September

Istanbul, Turkey

www.fdiworldental.org

The British Society of Paediatric Dentistry– Annual Meeting 2013

17–20 September

East Scotland, UK

www.bspd.co.uk

American Academy of Periodontology (AAP) – 99th Annual Meeting

28 September –1 October

Philadelphia, USA

www.perio.org

World Congress on Preventive Dentistry

9–12 October

Budapest, Hungary

www.iadr.com

European Association for Osseointegration

16–19 October

Dublin, Ireland,

www.eao.org.

The AOS 9th Biennial Conference and Exhibition

23-25 October

Perth, Australia

www.aosconference.com.au

American Dental Association (ADA) – 154th Annual Session

31 October–3 November

New Orleans, USA

www.ada.org

Greater New York Dental Meeting

29 November–4 December

New York, USA

www.gnydm.com

The ADF Congress

26- 30 November

Paris, France

www.adfcongres.com

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www.iajd.org t 'VMM JOTUJUVUJPOBM NBJMJOH BEESFTTFT t &NBJM BEESFTTFT Abstract The manuscript should contain an abstract. The abstract should be self-contained and citation-free and should not exceed 150 words.

Introduction This section should be succinct, with no subheadings.

Acknowledgments All acknowledgments (if any) should be included at the very end of the paper before the references and may include supporting grants, presentations, and so forth.

References Authors are responsible for ensuring that the information in each reference is complete and accurate. All references must be numbered consecutively and citations of references in text should be identified using numbers in square brackets (e.g., “as discussed by Smith [9]”; “as discussed elsewhere [9, 10]”).

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Note aux auteurs Le comité rédactionnel de la revue IAJD a décidé de publier tous les articles simultanément en versions française et anglaise. Cette décision prendra cours à dater du prochain numéro.

La nouvelle présentation devra faciliter indistinctement à tous nos lecteurs l’accès à tous les articles dans la langue de leur choix.

Dorénavant, Il est demandé aux auteurs de nous soumettre les deux versions sur le site.

Ceux qui n’ont pas la maitrise rédactionnelle dans la 2ème langue pourraient se faire assister de la personne adéquate, de sorte à ce que la syntaxe puisse satisfaire aux exigences de la rédaction scientifique.

La traduction littérale par le biais de certains moteurs de recherche n’est pas appréciable et ne peut en aucune manière exprimer correctement et avec précision les idées rédigées en première intention.

Note to authors The editorial board of the journal IAJD decided to publish all items simultaneously in English and French. This decision will take over dating from the next issue.

This new format will facilitate indiscriminately to all our readers the access to all articles in the language of their choice.

From now on, authors are asked to submit both versions on the site.

Those who do not have the mastery of drafting in the 2nd language could be assisted by the right person, so that the syntax can fulfill the requirements of scientific writing.

Literal translation through some search engine (Google...) is not significant and can not in any way correctly and accurately express the ideas drafted in first intention.

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February 2013

ISSN 2218-0885

International Arab Journal of Dentistry ‫المجلة العربية الدولية لطب االسنان‬

Vol. 4 – Issue 1

Revue arabe internationale de dentisterie

Vol. 4 – Issue 1