International Dental Research by Özkan ADIGÜZEL

Internation I nal Dental Research h Volume 1 - Numberr 1 - 2011

TABLE E OF CONTENTS ARTIICLE Rem moval of Deb bris and Sm mear Layer in n Curved Ro oot Canals Using U Self-A Adjusting Fi le with Diffe erent Operattion Times – A Scan nning Electrron Microsco ope Study Sene em YİĞİT ÖZE ER, Özkan AD DIGÜZEL, Sad dullah KAYA Page es 1-6

ARTIICLE The Gingival Crrevicular Flu uid Levels of o IL- 1β, IL-6 6 and TNF-α α in Late Adult Rats Filiz ACUN KAYA,, Seher GÜND DÜZ ARSLAN, Can Ayhan K KAYA, Hüseyiin ARSLAN, Orhan O HAMAM MCI es 7-12 Page

ARTIICLE Com mparing MTA A and Ketac c Molar Easy ymix for Furrcation Perfforation Rep pair Using a Volumetric c Method Sadu ullah KAYA, S Selengül GANİİDAĞLI AYAZ Z, Mehmet Sin nan DOĞAN, Haluk H AYDIN Page es 13-17

RE EVIEW ARTIICLE A Liiterature Review of Selff Adjusting File Özka an ADIGÜZEL L Page es 18-25

RE EVIEW ARTIICLE ntemporary Permanent Luting Agen nts Used in Dentistry: A Literature Review Con Ebru u SÜMER, Yalçın DEĞER Page es 26-31

RE EVIEW ARTIICLE gnosis and T Treatment Modalities M of o Internal an nd External Cervical Ro oot Resorptiions: Review w of the Diag Literature with Case Reporrts Sene em Yiğit Özer Page es 32-37

CASE REP PORT A Fiibre-Reinforrced Fixed Partial P Dentu ure on a Hem misectioned d Tooth: A Case C Reportt Süleyman AGÜLO OĞLU, Emrah AYNA, Eylem m ÖZDEMİR es 38-41 Page

Volume 1 - Numberr 1 - 2011

Original Article

Int Dent Res 2011;1:1-6

Removal of Debris and Smear Layer in Curved Root Canals Using Self-Adjusting File with Different Operation Times – A Scanning Electron Microscope Study Senem YİĞİT ÖZER1, Özkan ADIGÜZEL1, Sadullah KAYA1 1

Assistant Professor, Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, Diyarbakır, TURKEY

Abstract

Key Words Apical third of root canal, curved root canal, debridement, self-adjusting file, smear layer

Correspondence:

Senem YİĞİT ÖZER Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, 21280, Diyarbakir, TURKEY. e-mail: senemygt@hotmail.com

Aim: Debridement during root canal treatment is mandatory and it is provided by means of chemomechanical instrumentation and irrigation methods. This article analysis the debridement capacity of a novel system, SAF and its special irrigation device when used with different operation times in curved root canals. Methodology: 30 mesiobuccal root canals of maxillary molars were instrumented using SAF. Teeth were divided into three groups. In Group 1, 10 new SAF files were used for operation for 4 minutes. In Group 2, the 4-min previously used SAF files were operated in the same manner. In Group 3, the 8-min previously used SAF files were operated. During SAF operation 2.6 % NaOCl and 17 % EDTA were used alternately in all groups. Debris and smear layer removal were evaluated for the apical thirds under scanning electron microscope. Results: Non-used, 4-min preused, and 8-min preused SAF efficiently removed debris and smear layer in the apical thirds. There were no significant difference among the groups in terms of debridement. Conclusions: When SAF is operated in curved root canals with continous flow of irrigation it results in debris and smear-free canal walls in the critical apical thirds within 12 minutes. (Int Dent Res 2011;1:1-6)

Introduction Root canal instrumentation produces smear layer. This amorphous structure is composed of dentin particles, necrotic debris, and odontoblastic processes that occlude the orifices of dentinal tubules (1). Smear layer is reported to prevent the penetration of irrigation solutions, medications, and filling materials into dentinal tubules and many researchers believe that it is detrimental (2). The literature reports generally show that regardless of the instrumentation and irrigation techniques, the effectiveness of irrigating solutions remains limited International Dental Research © 2011

in the apical one third of a prepared canal. This is particularly true for curved root canals (3). Therefore, the improvement of irrigating protocols is essential during root canal treatment in order to achieve better cleaning efficiency especially in the very complex apical area. Rotary nickel-titanium files are successful to clean and shape the straight and narrow canals,and completion of the file sequence may result in a clean canal with no tissue debris and with removal of all or most of the inner layer of the heavily contaminated dentin (4). Recently micro–computed tomographic studies by Peters et al (5) have extended the

Using Self-Adjusting File in Curved Root Canals

understanding of the limitations of rotary file systems reporting that inadequate preparation often occurs in curved root canals. In upper molars treated with a conventional rotary system, 49% of the canal walls were reported to be untouched, even in the larger palatal canals (6). To overcome this handicap, these common nickel-titanium file designs are being modified for a higher percent of the root canal surface to be prepared by the shaping procedure (7). Self-Adjusting file (SAF) is a novel system among the nickel-titanium files operating in a different manner. It adapts itself longitudinally to a curved canal, as most rotary nickel-titanium files do, but differently adapts itself to the cross-section of the canal (7). It is a hollow file designed as a compressible, thin-walled, pointed cylinder, composed of a thin derivate of nickel-titanium lattice with high torsional and fatigue resistance. The lattice surface is slightly abrasive and it allows removing dentin with a back-and-forth grinding motion (8). This reciprocating file system is used with a specially designed irrigation device providing continuous flow of the irrigant. During the operating procedure, SAF is inserted into the canal while vibrating and is lightly pushed in until it reaches the predetermined working length. It is then operated with in-and-out manual motion and with continuous irrigation using two cycles of 2 minutes each for a total of 4 minutes per canal. This procedure is reported to remove a uniform dentin layer 60- to 75-mm thick from the canal circumference (8). Every available rotary file systems are reported to generate a smear layer leaving debris in the root canal (9) however a recent study by Metzger et al. (10), who used the SAF system with a 4-min application of 3% NaOCl and 17% EDTA reported clean and mostly smear layer–free dentinal surface in all parts of the root canal. However the evaluative tests showed the efficacy of the SAF file declined with time. A file that was preused for 30 minutes was found to be 40% less effective than a new file (8). Nevertheless, when used for 12 minutes, according to the manufacturer’s instructions, the SAF efficacy was not reported to substantially reduce. However the ability to remove dentin is claimed to decrease if the file was reused (8). Thus the aim of this present study was to evaluate the debridement capacity of SAF when used in curved root canals in an operation time as advised by the manufacturer. The null hypothesis is when SAF is used within 12 minutes it removes smear layer and debris efficiently in the apical thirds of curved root canals.

Yiğit Özer et al.

Materials and Methods Selection of Teeth

The study sample consisted of 30 maxillary molars with fully formed apices that had been extracted for periodontal and/or prosthetic reasons. The teeth were stored in 10% buffered formalin until they were used. The mesiobuccal (MB) root canals of maxillary molars were instrumented using SAF. Curvature of the MB canals was measured according to the protocoldescribed previously by Estrela et al. (11). The 30 canals showed curvatures ranging from 32 to 45°. This sample was equally divided into 3 groups of 10 teeth for instrumentation with SAF. The working length of each canal was determined by subtracting 1mm from the observed length of protrusion of the number 10 file through the apical foramen.

Root Canal Instrumentation Irrigation with the SAF

and

After endodontic accesss cavity, the root canal was negotiated using a size 10 K-file. The working lengths were set 1 mm shorter than the apical foramen. A glide path was established by manual instrumentation up to a size 20 K-file. The 10 SAF files were operated using an in-and-out vibrating handpiece as described by Metzger et al. (6) with 5000 vibrations/min and a 0.4-mm amplitude, with the irrigation device (VATEA; ReDent-Nova) that provided flow of the irrigation solution at a flow rate of 5 mL/min until it reached the predetermined working length for 4 minutes. The irrigation solution flowed into the file and freely escaped into the root canal through the lattice wall to backflow coronally without positive pressure. Because a flow rate of 5 mL/min was chosen, 15 mL of NaOCl (2.6%) and 5 mL of EDTA (17%) were used. NaOCl was used as the initial irrigant during the first 3 min of the operation, followed by 1 min of irrigation with EDTA. A final flush with 5 mL NaOCl was used to remove the EDTA, and distilled water was used in the last step. The canals were dried using paper points. In Group 1, 10 new SAF files were used for operation for 4 minutes. In Group 2, the 4-min previously used SAF files were operated in the same manner. In Group 3, the 8-min previously used SAF files were operated.

SEM Evaluation

Two longitudinal grooves were prepared on the buccal and lingual surfaces of each root using a diamond disc, avoiding penetration into the canal. The roots were then split into 2 halves with a chisel and coded. The coded specimens were mounted on metallic stubs, gold sputtered, and examined

IDR — Volume 1, Number 1, 2011

Yiğit Özer e et al.

Using Self-Adjustinng File in Curv ved Root Cana als

independe ently by two o observers using SEM M (Leo Stereoscan n S440, Leicca, Wetzlar,, Germany). After general e evaluation of o the can nal wall, 2 SEM photomicro ographs werre taken at magnificatio ons of 2000 at tthe apical (2 2 mm to ape ex) thirds off each specimen for the sme ear layer and d 200 for d debris. uated using a 5-point sscoring Cleanlinesss was evalu system inttroduced by Hülsmann ett al (12). (1)) score 1: no sme ear layer, and a all denttinal tubules were open; (2) score 2: a small amoun nt of smear layer, bules were open; o (3) sco and some dentinal tub ore 3: ous smear la ayer coverin ng the root canal homogeno wall, and o only a few de entinal tubules open; (4)) score 4: compllete root canal wall covered by a homogene eous smear layer, and no open deentinal tubules w were observe ed; and (5) score 5: h heavy, homogene eous smear layer coverring the com mplete root canal wall. The presence off debris was evaluated from images att 200X magnification ussing a scalee of 5 scores (12 2) as follows: (1) score 1: 1 clean roott canal wall and o only a few sm mall debris particles, p (2) score 2: a few sm mall agglome erations of debris, d (3) sccore 3: many agg glomerations of debris covering c lesss than 50% of th he root canal wall, (4) sccore 4: moree than 50% of tthe root can nal walls were w covered d with debris, and d (5) score 5: 5 complete or o nearly com mplete root canal wall coverag ge with debris. hen grouped d into ‘‘clean canal All ressults were th wall’’ that included sco ores 1 and 2 or ‘‘smearr layer s of 3, 4 4, and and debriss present’’ that included scores 5. Two examiners independently scored eaach of ages, which were code ed and ran ndomly these ima mixed so that the exxaminers we ere blinded tto the en sample orriginated. area from which a give n two examin ners indepen ndently agreeed on When a score, it was reccorded. Wh hen disagreeement d the sample a nd its occurred, both two discussed nd an agreed d score was reached. r scoring, an

the roots were e free of debbris, this ratio was 87% in the 8-min use ed group. FFinally 12-min group was 74 4% . Statistic cally there w was no differrence betwee en the experimental groups (PP >.05).

Fig gure 1. Distribution off debris sco ores at apiccal lev vels. Data were dicchotomized for graph hic illu ustration: sco ores 1–2 (cleean canal wa all) versus 3– –5 (debris present).

Sm mear Layer

Operating g SAF witth 4, 8, and 12-m min ap pplications re esulted in a rroot canal su urface clean of sm mear layer (F Fig. 2). In thhe apical thirds, 15 out of 30 0 were scorred as eithher 1 or 2,, respectively, representing a clean denntin surface. 4-min grou up 6 8-min group repre esented 61% %, represented 64%, nd 12-min grroup represeented 57% in smear layyer an scores of 1 or o 2, respecttively. Differrent operatio on me of SAF within 12 min utes remove ed smear layyer tim alm most equally y in the apiical thirds. No N differences be etween group ps were deteected statisticcally (P >.05 5).

cal Analys sis Statistic

Statisstical analysis was performed by using nonparame etric analysis of varian nce. Results were regarded as significcant if p < .05. M Multiple comparisons were adjusted by usiing the Bonfferroni correction..

R Results Debris

Root canal preparration using the SAF forr three groups re endered all root canals clean of d debris. Debris eva aluation of th he root canal dentinal su urfaces usually re esulted in debris scores of 1 or 2, representin ng a clean root r canal surface (Figu ure 1). In the new w SAF group p 90% of th he apical thiirds of Internatio onal Dental Research R © 2011

Fig gure 2. Distribution oof smear lay yer scores at ap pical levels. Data were dichotomize ed for graph hic illu ustration: sco ores 1–2 (cleean canal wa all) versus 3– –5 (sm mear layer present). p

Using Self-Adju usting File in Curved C Root Ca anals

Yiğitt Özer et al.

Figure 3. The smear laye er in the apiccal third of ccurved root canal c (A1-2) ) After 4-minn operation of o new SAF + dual-irrigation regime the t root cana al surface is free of debrris and smear layer leavinng the dentinal tubules open; (B1-2)) the 4-min preused p SAF were used w with the dua al-irrigation re egime. Most of the dentiinal tubules were w open witth a score 1--2; (C1-2) the 8-min preeused SAF + dual-irrigation regime reepresenting score s 2-3.

Discu ussion Debridem ment of the e root canal system iss a major m concern n for endodo ontic successs and irrigattion iss an importtant part off root cana al debridemeent especially in ccurved root canals (13). Unfortunateely, many m studiess have repo orted that currently ussed methods m of ro oot canal prreparation an nd irrigation do not effectivelyy debride th he entire roo ot canal systeem 9). Ideally, root canal irrigants should flush o out (9 debris, dissolve organic tissue, desstroy microb bial e the smea ar layer. P Past byproducts, and remove nal preparattion sttudies have shown thatt current can and irrigation methods may m be effecttive at clean ing he coronal p portions of root r canals but much leess th 4

als (14,15). effecttive in the apical portioons of cana Although several studies indiccate that ach hieving this goal in the apica al third of tthe root can nal may be ult if not im mpossible, thhe use of the t SAF in difficu comb bination with a dual-irriggation regime e of NaOCl and EDTA is reported to rresult in cle ean dentin a portioon of most root r canals surfacces in the apical (10). Recently th he study ressults of Mettzger et al. r 65% root caanal wall fre ee of smear (10) represented layer for the apiical thirds oof the root canal. Our y. In the 4resultts are in line with this prrevious study min used u SAF sm mear layer w was removed d 64 %, 8min used u SAF 61%, and 122-min used SAF 57%, respe ectively. Sodium S hypo ochlorite hass the ability to dissolve organ nic debris, and a destroyy microbial byproducts IDR — Voolume 1, Number 1, 2011

Yiğit Özer et al.

Using Self-Adjusting File in Curved Root Canals

(16). EDTA is a chelating agent used to remove the smear layer (17). This dual combination of irrigants has been shown to be effective in debriding and disinfecting root canals as well as other irrigants (18-21). Studies have shown an increased efficacy of canal debridement with increased apical size preparations and increased taper of instruments (14,22). As reported recently by Peters et al (5) the resulting apical size is usually at least equivalent to a #40 file when SAF is used during preparation in 5minutes. Several studies confirmed that larger apical preparation reduces the bacterial count (23,24) and enhances the effectiveness of irrigation (25). Probably apical preparation performed using SAF and vibrating motion of the file’s delicate mesh within the fluid that is continuously replaced had synergist effect for debridement and resulted with clean root canals almost free of smear layer on the critical apical region. In addition, the role of chlorine should not be overlooked. It is known that chlorine is responsible for the dissolution of organic tissue and the antimicrobial effect of NaOCl (26). However, chlorine is consumed rapidly during the first phase of tissue dissolution, probably within 2 min (26,27). Therefore regular replenishment and large volumes of NaOCl are required for successful debridement. During SAF operation with continous irrigation, one should consider that NaOCl is refreshed every second making it possible for sufficient free chlorine to be present in the root canal to dissolve the organic component of dentine debris. It could be possible that NaOCl contains enough free chlorine to dissolve the organic component of the dentine debris and despite the increased operation time with the used files NaOCl had enough flushing effect on debridement especially at the apical portions of the curved root canals. NaOCl entering the file through a free-rotating hub is continuously replaced during the procedure, thus providing a fresh and totally active irrigation solution. Because positive pressure is absent throughout the root canal system, the solution can easily escape through openings in the lattice of the file (8). The success in removing the smear layer in the apical third, may be due to the vibrating motion of the file’s delicate mesh within the fluid that is continuously replaced.

References 1. 2. 3.

8. 9.

10.

11.

12.

13.

Conclusions

14.

When SAF is operated in curved root canals with continous flow of irrigation it results in debris and smear-free canal walls in the critical apical thirds within 12 minutes. Thus our null hypothesis is accepted.

15.

16.

McComb D, Smith DC. A preliminary scanning electron microscopic study of root canals after endodontic procedures. J Endod 1975;1:238–42. Karagöz-Küçükay I, Bayirli G. An apical leakage study in the presence and absence of the smear layer. Int Endod J 1994;27;87-93. Sedgley CM, Nagel AC, Hall D, et al. Influence of irrigant needle depth in removing bioluminescent bacteria inoculated into instrumented root canals using real-time imaging in vitro. Int Endod J 2005;38:97–104. Wu M-K, van der Sluis LWM, Wesselink PR. The capacity of two hand instrumentation techniques to remove the inner layer of dentin in oval canals. Int Endod J 2003; 36:218–24. Peters OA, Boessler C, Paque´ F. Root canal preparation with a novel nickel-titanium instrument evaluated with micro-computed tomography: canal surface preparation over time J Endod 2010;36:1068–72. Peters OA, Peters CI, Schönenberger K, et al. ProTaper rotary root canal preparation: effects of root canal anatomy on final shape analyzed by micro CT. Int Endod J 2003;36:86–92. Metzger Z, Teperovich E, Zary R, et al. Respecting the root canal: a new concept of a Self Adjusting File (SAF). J Endod 2010;36:679– 90. Hof R, Perevalov V, Eltanani M, Zary R, Metzger Z. The Self Adjusting File (SAF), Part 2: mechanical analysis. J Endod 2010;36:691-96. Torabinejad M, Handisides R, Khamedi AA, et al. Clinical implications of smear layer in endodontics: a review. Oral Surg Oral Med Oral Path Oral Radiol Endod 2002;94: 658–66. Metzger Z, Teperovich E, Cohen R, et al. The Self Adjusting File (SAF). Part 3: Removal of debris and smear layer. A scanning electron microscope study. J Endod 2010;36;697-702. Estrela C, Bueno MR, Sousa-Neto MD, Pécora JD. Method for determination of root curvature radius using cone-beam computed tomography images. Braz Dent J 2008;2:114-8. Hülsmann M, Ruümmelin C, Schäfers F. Root canal cleanliness after preparation with different endodontic handpieces and hand instruments: a comparative SEM investigation. J Endod 1997;23:301–6. Bystrom A, Sundqvist G. Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res 1981;89:321– 8. Usman N, Baumgartner JC, Marshall JG. Influence of instrument size on root canal debridement. J Endod 2004;30:110 –2. Walters MJ, Baumgartner JC, Marshall JG. Efficacy of irrigation with rotary instrumentation. J Endod 2002;28:837–9. Hand RE, Smith ML, Harrison JW. Analysis of the effect of dilution on the necrotic tissue dissolution property of sodium hypochlorite. J Endod 1978;4:60–4.

Using Self-Adjusting File in Curved Root Canals

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17. Baumgartner JC, Mader C. A scanning electron microscopic evaluation of four root canal irrigation regimens. J Endod 1987;13:147–52. 18. Bystrom A, Sundqvist G. The antibacterial action of sodium hypochlorite and EDTA in 60 cases of endodontic therapy. Int Endod J 1985;1:35– 40. 19. Baumgartner JC, Mader C. A scanning electron microscopic evaluation of four root canal irrigation regimens. J Endod 1987;13:147–52. 20. Johal S, Baumgartner JC, Marshall JG. Comparison of the antimicrobial effect of 1.3% NaOCl/MTAD with 5.25% NaOCl/15% EDTA for root canal irrigation. J Endod 2007; 33:48 –51. 21. Kho P, Baumgartner JC. A comparison of the antimicrobial efficacy of NaOCI/Biopure MTAD versus NaOCI/EDTA against Enterococcus faecalis. J Endod 2006;32:652–5. 22. Wu MK, Wesselink PR. Efficacy of three techniques in cleaning the apical portion ofcurved root canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1995;79:492– 6. 23. Card SJ, Sigurdsson A, Orstavik D, Trope M. The effectiveness of increased apical enlargement in reducing intracanal bacteria. J Endod 2002; 28:779–83. 24. Rollison S, Barnett F, Stevens RH. Efficacy of bacterial removal from instrumented root canals in vitro related to instrumentation technique and size. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2002;94:366–71. 25. Chow TW. Mechanical effectiveness of root canal irrigation. J Endod 1983;9:475–9. 26. Moorer WR, Wesselink PR. Factors promoting the tissue dissolving capability of sodium hypochlorite. Int Endod J 1982;15:187-96. 27. Van der Sluis WM, Gambarini G, 2, Wu MK, Wesselink PR. The influence of volume, type of irrigant and flushing method on removing artificially placed dentine debris from the apical root canal during passive ultrasonic irrigation. Int Endod J 2006;39:472-76.

IDR — Volume 1, Number 1, 2011

Original Article

Int Dent Res 2011;1:7-12

The Gingival Crevicular Fluid Levels of IL1β, IL-6 and TNF-α in Late Adult Rats Filiz ACUN KAYA1, Seher GÜNDÜZ ARSLAN2, Can Ayhan KAYA3, Hüseyin ARSLAN4, Orhan HAMAMCI5 1

Associate Professor, Dicle University, Faculty of Dentistry, Deparment of Periodontology, Diyarbakır, Turkey. Associate Professor, Dicle University, Faculty of Dentistry, Deparment of Orthodontics, Diyarbakır, Turkey. 3 Dr, PhD, Meat and Fish Corporation, Department of Veterinary Diyarbakır,Turkey 4 Associate Professor, Dicle University, Faculty of Medicine, Deparment of Orthopedics and Traumatology, Diyarbakır, Turkey. 5 Professor, Dicle University Faculty of Dentistry, Deparment of Orthodontics, Diyarbakır, Turkey. 2

Abstract Key Words Orthodontic tooth movement, gingival crevicular fluid, IL-1β, IL-6,TNF-α,late adult rat.

Correspondence:

Filiz ACUN KAYA, Associate Professor, Dicle University, Faculty of Dentistry, Department of Periodontology, 21280 Diyarbakır, Turkey e-mail: facunkaya@gmail.com

Aim: To evaluate the levels of interleukin1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in the samples of gingival crevicular fluid (GCF) taken from the late adult rats during the orthodontic tooth movement and to evaluate the responses to orthodontic treatment . Methodology: In experiment 19 adult (120 days) Spraque-Dawley rats were used. Approximately 15 g force applying open coil spring was applied actively between the upper incisors of the rats. Before and after the activation on the 3rd and 7th and 10th days GCF samples were taken from the vestibular surfaces of appliance fixed teeth using periopaper®. Then the samples were biochemically analyzed. For the statistical analysis of working days of each cytokines repetitive variance analysis technique was used. Results: The levels of IL-1β, IL-6 and TNF-α were the highest in the 3rd day and started to decrease on the 7th and 10th days. Conclusions: The cytokine levels of orthodontic force applied teeth in late adult rats are compatible with the levels of studies in young rats. (Int Dent Res 2011;1:7-12)

Introduction Although a tremendous increase in the demand for adult orthodontic therapy was seen in the past decades, our knowledge on the efficiency of adult tooth movement through the alveolar bone in adults is indeed possible by means of treatments modalities based on experiences in adolescent. However, certain treatments seem to be more time-consuming in adult than juvenile patients. This Goz to the conclusion that, in adults, the biological possibilities

for tooth movement are decreased to about onethird of those found in children (1). Orthodontic tooth movement is based on forceinduced periodontal ligament (PDL) and alveolar bone remodeling. Mechanical stimuli exerted on a tooth cause an inflammatory response in the periodontal tissues. Inflammatory mediators are released that trigger the biological processes associated with alveolar bone resorption and apposition (2-4). It was suggested that the presence of neuroimmune interactions may be of importance in 7

Le evels of IL-1β β, IL-6 and TN NF-α in Late Ad dult Rats

th he initial infflammatory response r an nd regenerattive processes off the PDLLs that are e incident to ement (5). An importaant orthodontic ttooth move ology was th he identificattion breakthrough in bone bio nes in bone remodelin ng. of the role of cytokin Cytokines C arre involved in initiatin ng, amplifyin ng, perpetuating, and resolvin ng inflammattory responsses. They T are key mediators for f tissue damage and p play an important role in tooth h movement (6). Cytokines are classifiied as proinfflammatory aand atory. Proinflammatory ones are TNFF-α, anti-inflamma L-1, interleukkin 2 (IL-2), IL-6, and interleukin 8 ((ILIL 8). Anti-inflam mmatory cyttokines are interleukins 4, 10, and 13. The proinfla ammatory ones o are alaarm ytokines, ind ducing vascullar dilatation with increassed cy permeability and enhancing inflamma atory respon nse 6). (6 okine that starts s the bo one IL-1 is a known cyto re esorption prrocess by ta aking part in n the survivval, fu usion, and acctivation of the t ostoeclassts (7,8) IL- 1β, a major physiologic form of IL-1, is mainly m secretted es and pa artially by macrophag ges, by monocyte asts, and epidermal ceells. endothelial ccells, fibrobla This T secretion n is activated d by various stimuli (7). All th hese studiess demonstrate that mecchanical stim muli activate infla ammatory cytokines (6,9). In a cat model, m Davidovitch et al.10 have loccalized inducced le evels of IL-1 1β and TNF F-α in the periodontium of te eeth undergo oing moveme ent. IL-1β and TNF-α affect bon ne metaboliism directly. At exxtremely low w concentratiions, IL-1β aand TNF-α T have b been implicatted in the process of bo one re emodeling th hrough speccific receptorrs on the bo one ce ell popula ation (11--13). Mon nocytes aand macrophages m do not consstituently produce IL-1β or TNF-α, T but on “activatiion” they synthesize s aand re elease these cytokines (1 13,14). responses r IL-6 rregulates immune in in nflammation sites and has h an auto ocrine/paracrrine activity that stimulates osteoclast formation aand bone resorbing activity of preformed osteoclaasts 8,9). (8 Various researcherss demonstrated elevatted le evels of cyttokines in tooth t move ement (12-1 14). Ly ynch et al (15) demon nstrated tha at in the eaarly sttages of too oth moveme ent (at 12 and a 24 hou urs) cy ytokines arre mostly seen in th he periodon ntal lig gament. All studies to determine the levels of cy ytokines in g gingival creviicular fluid (G GCF) evaluatted animal and human subjeccts for shortt times (11-1 18) These T studie es applied distalization d forces to tthe te eeth and searched forr early resp ponses to tthe fo orces. The aimss of this stud dy, to evaluate the levelss of IL L-1β, IL-6 a and TNF-α in the samp ples of gingiival crrevicular fluid (GCF) take en from the late adult rrats during the orthodontic toth move ement and to valuate the rresponses to o orthodontic treatment. ev

Acun n Kaya et al.

Materrials and d Method ds Anim mal Proce edures

In I experime ent 19 latte adult (120 days) Spraq que-Dawley rats r were useed. Approxim mately 15 g force applying op pen coil sprinng was appliied actively een the uppe er incisors off the rats (Fig g. 1). betwe

pring was appplied actively between Figurre 1. Coil sp the upper incisorss of the rats.

GCF F Sampling g GCF G samplin ng was obtaained with paper p strips (Perio opaper, Pro Flow, Amittyville, NY) using the metho od described d by Rudin ett al. (19) Sam mpling was performed on the e vestibular, mesial and distal sides e tooth to prevent salivaary contamin nation (Fig. of the 2). Sample S sites were isoolated, and the tooth surfacces were air-dried. Papper strips were w placed into the t sulcus an nd, after waiiting 30 seco onds. Paper stripss were stored d in sterile tuubes at −20°°C until the day of o the experim ment. Saliva S and blood contam mination was important; conta aminated samples weree excluded from the study y. GCF sampling was ddone before e all other clinica al examinatio ons were peerformed to prevent an increa ase in fluid volume. v Befoore examina ation of the GCF, 1000 μL ste erile NaCl (9 mg/mL) wa as added to paperr strips, and the GCF waas diluted att 3000 g at +5°C for 20 minutes (20).

IDR — Voolume 1, Number 1, 2011

Acun Kaya e et al.

Levels of o IL-1β,IL-6 aand TNF-α in Late Adult Ratts

hu uman buffer matrix was used. The amount of ILI 1β β, IL-6 and TNF-α deteccted in each h sample was co ompared witth IL-1β, ILL-6 and TN NF-α standard cu urve that demonstrate d es a directt relationsh hip be etween op ptical denntistry an nd cytokin ne co oncentration. The total aamount of IL L-1β, IL-6 an nd TN NF-α was dettermined in ppicograms.

on Sttatistical Evaluatio For the statistical anaalysis of wo orking days of ea ach interleu ukin repettitive variance analyssis tecchnique wass used.

Res ults Figure 2 2. GCF Periopaperr®.

sa ampling

with

wass obtained

Cytokines Analys sis

The immunoassa ay system and a the maachine g IL-1β, IL-6 I and TNF-α used for measuring mmulite (Diagnostic Pro oducts concentrattions was Im Corp, Los Angeles, Calif). For the manual diluttion of ples, IL-1β, IL-6 and TNF-α–free nonrats samp

The con ncentration of all cy ytokines an nd co omparision be etween the cytokine sam mpling period ds we ere shown in n Table1. The baseline levels foor the concentration of ILI 1β β, IL-6 and TNF-α inccreased on the 3th, but b de ecreased on th 7th and 10th days. The T difference be etween the sampling peeriods for all cytokines is sta atistically significant (P<..001).

okines accord ding to sampling periods. TABLE 1. The comparrision of cyto

Cytokine IL‐1β

IL‐6

TNF‐α

Samplingg period Baseline 3rd day 7th day 10th dayy Baseline 3rd day 7th day 10th dayy Baseline 3rd day 7th day 10th dayy

1) A

4.07 24.2 5B 17.002C 12.887D 7.02 A 22.5 1B 15.889C 12.9 8D 2.92 A 16.447B 12.009C 9.91 D

1.4 45 3.0 03 1.5 52 1.5 56 3.0 04 1.3 30 1.6 68 1.4 49 1.6 64 2.1 17 2.5 52 1.3 33

0.34 0.71 0.36 0.37 0.72 0.31 0.40 0.35 0.39 0.51 0.59 0.31

Min 2.30 20.10 15.10 10.20 2.50 20.10 12.10 10.50 1.10 11.10 8.10 7.10

Max 7.10 29.50 19.50 15.00 12.30 25.30 18.20 15.50 7.30 18.90 17.10 12.30

The differen nce betwen the 2 mean av verages show wn with differe ent letter in the same coluumn for the sa ame cytokine is statistically significant (P< <.001).

Dis scussion n When n an orthodontic force is applied to a tooth for a prolonged perio od of time, an inflamm matory response is initiated. As a resultt of this, a bone nd this p rocess resorption process begins an dates tooth movement m (2 21). accommod

The app pearance off osteoclastts and bon ne e critical faactors that initiate too oth resorption are ovement (22 2). Mononucclear osteoprogenitor ce ells mo in local tissuess require sevveral develop pmental stages to turn into full functional multinucleatted osteoclassts ones play an a (23). Various cytokines and hormo mportant role in this proceess (23, 24). im Due to the biologicaal limitationss of the adu ult bo one, since itt well-knownn that, during aging, th he bo one composiition changees, its cells become le ess 9

Levels of IL-1β, IL-6 and TNF-α in Late Adult Rats

reactive, and its metabolism slows (25, 26). Another possible cause might be the use of inappropriate stimuli, because the biological requirements for inducing optimal tissue responses in young and adult invidiuals may different (27).Concerning the age effect on bone activity, there is evidence that bone formative activity of osteoblasts and boneresorptive activity of osteoblast decrease with age (28, 29), but also, in adults, these cell may recover a higly activated state under orthodontic stimuli (30). This ractivation in adults, however, may take more than in jüveniles. The few experimental studies on age effects on orthodontic tooth movement have been performed in rats. Some of them indicate that tooth movement occurs at higer rates and over agreater distance in young than in adult rats (31—33) while others (26, 34) found similiar osteoblastic and osteoclastic activity during orthodontic tooth movement in young and adults rats (30, 34). By thinking the results of these studies;in our study no experimental groups in which young rats took place were performed. We thought that this study plan was much more suitable for the ethics of animal studies.Because of this reason, our findings were compared with the results of the studies performed in young rats. The testing site in this study was the gingival sulcus, because its access in the oral cavity is easy and it has a continuity with the PDL. In rats GCF studies micropipettes were used (35). But we used paper strips that are used frequently in human studies.The reason of choosing this method was that it was more practical and to understand whether this technique can be used in rats. The maxillary incisive teeths of all patients were monitored because these teeth are accessible. It has been shown that levels of biochemical markers in the GCF might depend on different collection sites (36, 37). For this reason, the incisives were used as both test and control teeth. The control data, collected at the baselines, were obtained before any force was applied. The continuous eruption of the mandibular incisors was bloced, and the incisors werw shortened and abrased to some degree during the experiment. Iwasaki et al (38) reported that IL-1β levels fluctuated with a 28-day cycle when a continuous orthodontic force was applied. In the early stages of orthodontic force application it has been shown that many PDL cells stain positively for IL-1β.10 Also, Lynch et al (15) reported that in the early stages of tooth movement (12 and 24 hours) many PDL cell types stained positively for IL-1β. Lowney et al (12) demonstrated that TNF-α plays a pivotal part in the assessment of orthodontic tooth movement. Tzannetou et al (18) used low and high forces to the maxillary molars to expand the palate. Low forces were produced by separator placement and

Acun Kaya et al.

higher forces by a palatal expansion device. They observed high levels of IL-1β levels with both the force levels. Also, Lee et al (39) demonstrated that the mean concentrations of IL-1β increase in the first 24 hours after continuous and interrupted forces. All these studies examined GCF in short time periods as compared with this study. They found that especially in the first 24 hours, cytokine levels increased and then equilibrium is reached, which is higher than the baseline levels. King et al (40) described an early phase of bone resorption (3–5 days), its reversal (5–7 days), and a late phase (7–14 days) of bone deposition. A similar bone cycle has also been reported in humans (41, 42) but in humans this timing seems to be longer than in rats. In our study the aim was to evaluate the early ctokine levels and because of this the working period was limited to 10 days. The experimental tooth movement leads to significantly increased recruitment of cells that belong to the mononuclear phagocytic system, and it was suggested that the presence of neuroimmune interactions may be of importance in the initial inflammatory response and regenerative processes of the PDLs that are incident to orthodontic tooth movement (43). The macrophage has the ability to produce cytokines, such as IL-1β and IL-6, the levels of which are known to increase during orthodontic tooth movement (44). IL-1β may act synergistically with TNF-α (45) and be a powerful inducer of IL-6 (46, 47). IL-1β, IL-6 and TNF-α were suggested to stimulate bone resorption and bone-cell replication (48, 49) In our experiment, the maximal level was detected on day 3 after the application of orthodontic force. The decreased number of IL-1β, IL-6 and TNF-α on days 7 and 10.The spring did not require reactivation during the experiment. This fact may explain the reason that IL-1β, IL-6 and TNF-α levels were decreased at 7 and 10 days.

Conclusions The results of this study support the hypothesis that proinflammatory cytokines play a potent role in bone resorption after the application of orthodontic force. The changes in the cytokine levels supports the results of the studies which state that the young and adult rats have similar osteoblastic and osteoclastic activity during orthodontic movement. Also, in our study it was shown that the periopaper® can be used to obtain GCF in rats.

IDR — Volume 1, Number 1, 2011

Acun Kaya et al.

Levels of IL-1β,IL-6 and TNF-α in Late Adult Rats

References 14. 1. 2.

4. 5.

10.

11.

12.

13.

Goz G. The age dependence of the tissue reaction in tooth movements. Fortschr Kieferorthop 1990; 51: 4-7. Davidovitch Z, Finkelson MD, Steigman S, Shanfeld Jl, Montgomery Pc, Korostoff E. Electric currents, remodeling and orthodontic tooth movement. I. The effect of electric currents on periodontal cyclic nucleotide levels. Am J Orthod 1980;77:14-32. Davidovitch Z, Fınkelson MD, Steıgman S, Shanfeld Jl, Montgomery Pc, Korostoff E. Electric currents, remodeling and orthodontic tooth movement. II. Increase in rate of tooth movement and periodontal cyclic nucleotide levels by combined force and electric current. Am J Orthod 1980;77:33-47. Davidovitch Z. Tooth movement. Crit Rev Oral Biol Med 1991;2:411-50. Vandevska-Radunovic V, Hals Kvinnsland I, Kvinnsland S, Jonsson R. Immunocompetent cells in rat periodontal ligament and their recruitment incident to experimental orthodontic tooth movement. Eur J Oral Sci 1997; 105: 36-44. Stoycheva MS, Murdjeva MA. Correlation between serum levels of interleukin 1-β, interleukin 1-ra, interleukin-6, interleukin 10, interleukin 12, tumor necrosis factor-and interferon- with some clinical and laboratory parameters in patients with salmonellosis. Biotechnol Biotechnol Equip 2005;19:143-6. Scarel-Caminaga RM, Trevilatto PC, Souza AP, Brito RB JR, Line SRP. Investigation of an IL-2 polymorphism in patients with different levels of chronic periodontitis. J Clin Periodontol 2002;29:587-91. Okada N, Kobayashi M, Mugikura K, Okamatsu Y, Hanazawa S, Kıtano S, ET AL. Interleukin-6 production in human fibroblasts derived from periodontal tissues is differentially regulated by cytokines and a glucocorticoid. J Periodontol Res 1997;32:559-69. Kurıhara N, Bertolini D, Suda T, Akiyama Y, Roodman GD. Interleukin-6 stimulates osteoclastlike multinucleated cell formation in long-term human marrow cultures by inducing IL-1 release. J Immunol 1990;144:426-30. Davidovitch Z, Nicolay O, Ngan PW, Shanfeld JL. Neurotransmitters, cytokines and the control of alveolar bone remodeling in orthodontics. Dent Clin North Am 1988;32:411-35. Baggiolini M, Walz A, Kunkal Sl. Neutrophilactivating peptide- 1/IL-8, a novel cytokine that activates neutrophil. J Clin Invest 1989;84:10459. Lowney J, Norton L, Shafer D, Rossomando E. Orthodontic forces increase tumor necrosis factor in the human gingival sulcus. Am J Orthod Dentofacial Orthop 1995;108:519-24. Uematsu S, Mogi M, Deguchi T. IL-1, IL-6, tumor necrosis factor-α, epidermal growth factor and 2microglobulin levels are elevated in gingival

15.

16.

17.

18.

19.

20.

21. 22.

23. 24.

25. 26. 27. 28.

29.

crevicular fluid during human orthodontic tooth movement. J Dent Res 1996;75:562-7. Alhashimi N, Frıthiof L, Brudvik P, Bakhiet M. Orthodontic tooth movement and de novo synthesis of proinflammatory cytokines. Am J Orthod Dentofacial Orthop 2001;119:307-12. Lynch Pr, Davıdovıtch Z, Shanfeld J. Interleukin1β at bone resorption sites: localization during tooth movement in vivo. J Dent Res. 1988; 67:1474. Grıeve W, Johnson G, Moore R, Reinhardt R, Dubois L. Prostoglandin e (PGE) and Interleukin1 (IL-1) levels in gingival crevecular fluid during human orthodontic tooth movement. Am J Orthod Dentofacial Orthop 1994;105:369-74. Rossi M, Whitcomb S, Lindemann R. Interleukin1 and tumor necrosis factor production by human monocytes cultured with L-thyroxine and thyrocalcitonin: relation to severe root shortening. Am J Orthod Dentofacial Orthop 1996;110:399-404. Tzannetou S, Efstratiadis S, Nicolay O, Grbic J, Lamster I. Interleukin-1beta and betaglucuronidase in gingival crevicular fluid from molars during rapid palatal expansion. Am J Orthod Dentofacial Orthop 1998;115:686-96. Rudin HJ, Overdizk HF, Rateitschack KH. Correlations between sulcus fluid rate and clinical and histological inflammation of the marginal gingiva. Helv Odont Acta 1970;14:21-6. Rasmussen L, Hänström L, Lerner UH. Characterization of bone resorbing activity in gingival crevicular fluid from patients with periodontitis. J Clin Periodontol 2000; 27:41-52. Storey E. The nature of tooth movement. Am J Orthod 1973; 63:292–314. Proffii RW, Fıelds HW JR. The biological basis of orthodontic therapy. In: Rudolph P, ed. Contemporary Orthodontics. 3rd ed. St Louis, Mo: Mosby; 2000:296–325. Teıtelbaum SL. Bone resorption by osteoclasts: review. Science 2000; 289:1504–1508. Sandy JR, Farndale RW, Meikle MC. Recent advances in understanding mechanically induced bone remodeling and their relevance to orthodontic theory and practice. Am J Orthod Dentofacial Orthop 1993; 103:212–222. Baumhammers A, Stallard RE, Zander HA. Remodeling of alveolar bone. J Periodontol 1965; 36; 439-442. Klingsberg J, Butcher E. Comparative histology of age changes in oral tissues of rat, hamster,and monkey. J Dent Res 1960;39:158-169. Melsen B. Limitations in adult orthodontics. In: current controversies in orthodontics.Melsen B, editor. Chicago: Quintessence 1991,pp.147-180. Nishimoto SK, Chang CH, Gendler E, Stryker WF, Nimni ME. The effect of aging on bone formation in rats: biochemical and histological evidence for decreased bone formation capacity. Calcif Tissue Int 1985;37: 617-624. King GJ And Keeling SD. Orthodontic bone remodeling in relation to appliance decay. Angle Orthod 1995; 65:129-140.

Levels of IL-1β, IL-6 and TNF-α in Late Adult Rats 30. Kabasawa M, Ejiri S, Hanada K, Ozawa H. Effects of age on physiologic and mechanically stressed rat alveolar bone:a cytologic and histchemical study. Int J Adult Orthodon Orthognath Surg 1996; 11: 313-327. 31. Bridges T, King G, Mohammed A. The effect of age on tooth movement and mineral density in the alveolar tissues of the rat. Am J Ortohod Dentofac Orthop 1988;93: 245-250. 32. Kyomen S, Tanne K. Influences of aging changes in proliferative rate of PDL cells during experimental tooth movement in rats. Angle Orthod 1997; 67: 67-72. 33. Takano-Yamamoto T, Kawakimim, Yamashiro T. Effect of age on the rate of tooth movement in combination with local use of 1,25(oh)2D3 and mechanical forces in rat. J Dent Res 1992;71: 1487-1492. 34. Jager A, Radlanski RJ. Alveolar bone remodeling following Orthodontic tooth movement in aged rats. An animal experimental study. Dtsch Stamatol 1991; 41: 399-406. 35. Aarli V, Heyeraas KJ. Effect of venous stasis and hypoproteinemia in gingival fluid formation in rats. J Periodontal Res 1995 Jul; 30(4): 231-7. 36. Cumming BR, Löe H. Consistency of plaque distribution in individuals without special home care instruction. J Periodontal Res 1973;8:94100. 37. Ren Y ,Vissink A. Cytokines in crevicular fluid and orthodontic tooth movement. European Journal of Oral Sciences 2008;116: 89-97. 38. Iwasaki LR, Haack JE, Nıckel JC, Reınhardt RA, Petro TM. Human interleukin-1β and interleukin-1 receptor antagonist secretion and velocity of tooth movement. Arch Oral Biol. 2001; 46:185– 189. 39. Lee KJ, Park YC, Yu HS, Choı SH, Yoo YJ. Effects of continuous and interrupted orthodontic force on interleukin-1β and prostaglandin E2 production in gingival crevicular fluid. Am J Orthod Dentofacial Orthop. 2004;125:168–177. 40. King GJ, Keeling SD, Wronski TJ. Histomorphometric study of alveolar bone turnover in orthodontic tooth movement. Bone 1991; 12:401–409. 41. Egelberg J. Permeability of the dento-gingival blood vessels II: clinically healthy gingivae. J Periodontal Res. 1966; 1:276–286. 42. Rodan GA. Introduction to bone biology. Bone 1991; 13:3–6. 43. Vandevska-Radunovic V, Hals Kvinnsland I, Kvinnsland S, Jonsson R. Immunocompetent cells in rat periodontal ligament and their recruitment incident to experimental orthodontic tooth movement. Eur J Oral Sci 1997; 105: 36-44. 44. Saito M, Saito S, Ngan PW, Shanfeld J, Davıdovıtch Z. Interleukin -1β and prostaglandin E are involved in the response of periodontal cells to mechanical stress in vivo and in vitro. Am J Orthod Dentofacial Orthop 1991;99: 226-240. 45. Dinarello CA. Interlukin 1 and its biologically related cytokines. Adv Immunol 1989; 44: 153205.

Acun Kaya et al. 46. Linkhart TA, Linkhart SG, McCharles DC, Long DL, Strong DD. Interleukin-6 messenger RNA expression and interleukin-6 protein secretion in cells isolated from normal human bone: regulation by interleukin-1. J Bone Miner 1991; 6: 1285-1294. 47. Van Damme J, Opdennakker G. Simpson RJ, Rubira MR, Caphas S, Vink A. Identification of the human 26-KD protein, interferon beta-2 (IFNbeta), as a B cell hybridoma/plasmacytoma growth factor induced by interlukin-1 and tumor necrosis factor. J Exp Med 1987; 165: 914-919. 48. Canalis E. Effects of tomor necrosis factor on bone formation in vitro. Endocrinology 1987; 121: 1596-1604. 49. Bertolini DR, Nedwin GE, Bringman TS, Smith DD, Mundy GR. Stimulation of bone resorption and inhibition of bone formation in vitro by human tumor necrosis tomor necrosis factors. Nature 1986; 319: 516-518.

IDR — Volume 1, Number 1, 2011

Original Article

Int Dent Res 2011;1:13-17

Comparing MTA and Ketac Molar Easymix for Furcation Perforation Repair using a Volumetric Method Sadullah KAYA1, Selengül GANİDAĞLI AYAZ2, Mehmet Sinan DOĞAN3, Haluk AYDIN4 1

Dicle Dicle 3 Dicle 4 Dicle 2

University, University, University, University,

Faculty of Dentistry, Department of Operative Dentistry and Endodontics, Diyarbakir, Turkey Faculty of Dentistry, Department of Operative Dentistry and Endodontics, Diyarbakir, Turkey Faculty of Dentistry, Department of Pediatric Dentistry, Diyarbakir, Turkey Science and Arts Faculty, Department of Chemistry, Diyarbakir, Turkey

Abstract Key Words MTA, Ketac Molar Easymix, volume measurement method, methylene blue.

Correspondence:

Sadullah KAYA Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, 21280, Diyarbakir, TURKEY. e-mail: sadullahkaya@hotmail.com

Aim: We compared the ability of mineral trioxide aggregate (MTA) and Ketac Molar Easymix (KM) to repair furcal perforations in extracted human molars, based on the volume of methylene blue dye penetration. Methodology: In total, 44 human mandibular molars were divided randomly into two (n = 20 each) experimental groups, with two teeth used as positive controls and two teeth without perforations used as negative controls. Group 1 was repaired with MTA and group 2 with Ketac Molar Easymix. The volumetric determination of dye penetration was based on the molecular characteristics of methylene blue. The standard area of a methylene blue particle is known and the surface area can be calculated. We converted the dye penetration area into a volume and performed quantitative analyses. Results: Volume measurement using the dye penetration method showed that KM resulted in more microleakage than MTA (p < 0.05). Conclusions: Mineral trioxide aggregate resulted in significantly less dye leakage than Ketac Molar Easymix using a volumetric measurement method. (Int Dent Res 2011;1:13-17)

Introduction Perforations of teeth are procedural accidents that can have adverse effects on the success of endodontic treatment. The etiology of dental perforations includes deep caries, resorption, or iatrogenic factors. Regardless of the cause, a perforation allows microorganisms to invade the supporting structures, triggering inflammation and a loss of attachment, which may ultimately compromise the prognosis of the tooth (1, 2). In a literature review, Alhadainy (3) stated the ideal features of a perforation repair material: it should be biocompatible, non-toxic, radiopaque, nonresorbable, and bacteriostatic, and have excellent

sealing qualities. Additionally, the repair material should be esthetically pleasing. Mineral trioxide aggregate (MTA) is used for furcation repair, resorption treatment, pulpotomy procedures, and capping pulps with reversible pulpitis (4-6). However, one major disadvantages of using MTA is its long setting time (7). Glass ionomer cements are popular in restorative dentistry because of their esthetic properties. Clinical studies have provided evidence of the effectiveness of Ketac Molar as a restorative (8). The adhesion of Ketac Molar Easymix (KM) to dental tissue relies primarily on a chemical interaction and to a lesser extent on micromechanical interlocking (9). Several leakage models have been used to assess the ability of 13

Fu urcation perfo oration and volume measure ement method d

materials m to seal furcatiion perforattions, includ ing dye extraction n, dye pene etration, fluid d filtration, aand bacterial leakkage modelss (10). One of the maajor en using dye es to examine e penetration n is problems whe he air trappe ed in voids along a root ca anal fillings ( 11, th 12). Dye extra action studie es also use dye penetratio on. n this me ethod, samples staine ed using 2 2% In methylene m blu ue are store ed in a herm metically sea led vial containing g 65% nitricc acid for 3 days. The viials ged at high h speed to separate tthe are centrifug xtracted dye e from the soluble s dental tissues. T The ex su upernatant ffrom each sample s is the en analyzed in an ultraviolet-visible spectrophottometer w with co oncentrated nitric acid ass the blank (10, 13). e dye-extracction method d, Hamad et al. Using the (1 14) compare ed the sealin ng ability of gray g and wh hite MTA M when used for furccation perforration repair of te eeth. No sig gnificant diffference betw ween gray aand white w MTA wa as observed. The theo ory underlyiing the use of methyleene blue to meassure the miccroleakage surface s areaa is adsorption ch haracteristicss, which can be based on its a xplained by the collectio on of molecu ules, atoms, or ex io ons in any so olution on the surface of a solid when n it tu urns into the e gas, vapor,, or liquid ph hase (15). T This method m can be used to o determine e the mass or vo olume of methylene blu ue. In this technique, t M MB, which w has a kno own moleccular weig ght (M MA = 319.86 68 g.mol-1), wavelength (λmaax)

Kaya et al.

urface area (662 nm), color index (520115), and su ( (σ = 120 A0.2), iss used as thee adsorbent (15). In I this study y, we compaared the ability of MTA and Ketac Molar Easymixx to seal furcation m ng volume perforations in mandibular molars usin ethod. measurement with the dye peenetration me

Materrials and d Method ds Forty-four F ex xtracted, hum man mandibular molars were used. All tee eth were stoored in distille ed water at u used. Th he molars w were decoronated 3 mm 4°C until above e the cemen nto-enamel jjunction and d the roots were amputated 3 mm below w the furcatiion using a tapered diamond stone. A sttandardized endodontic w made in each tooth, sticky wax accesss opening was was placed p over the orifice oof each cana al, and the teeth,, including the t pulpal flloor, were coated c with three layers of red nail varnissh. To ensure e that each e roots, a perforation was centered bbetween the n diameter was made from the defecct 2 mm in extern nal surface with a #3 high-speed round bur (Fig. 1, A-B). The e teeth weree divided ran ndomly into g and the perforaations were sealed as two groups follow ws: Groups G 1 (n = 20) repairred with MTA A (Dentsply Tulsa Dental, Tulssa, OK), Grouups 2 (n = 20) repaired olar Easymixx (3M ES SPE AG)-a with Ketac Mo

Figure 1 1. (A) Pulpal flor; and (B) ( furcal vviews of the perforation. A view off a tooth tre eated with e blue; (C) Orthograde O direction; d (D)) retrograde direction. methylene 14 1

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Kaya et al.

Furcation perfforation and vvolume measurement metho od

chemicallyy cured glasss ionomer ce ement. Two teeth with unrep paired perforations were e used as po ositive controls a and two tee eth without perforations were used as n negative con ntrols. Teeth h were storeed for 24 h at 37 7°C and 100% % humidity in an incubaator to allow settting of MTA A and KM. Each group p was placed in petri dishess. All sample es were sto red in e blue for 72 h (Fig. 1, C-D). After reemoval methylene from the d dye, teeth we ere rinsed un nder tap watter for 60 min and d varnish rem moved with a polishing d disc.

Volume measure ement me ethod

Samp ples (n = 40) were placed into o two different glass vialls containin ng 20 m mL of concentratted 65% nitrric acid until they all disssolved completelyy approxima ately for 72-h. The MB B that filled the m microleakage e gaps also dissolved in n nitric acid. At tthe end off the adsorption period d, the solution w was centifuga ated for 20 min at 3000 0 rpm. After centtrifugation, the t dye con ncentration iin the supernatan nt solutions was an nalyzed usi ng a UV-spectro ophotometerr (Shimadzu UV-160, Shim madzu Corp., Kyo oto, Japan) by b monitoring the absorb bance. The abssorption w wavelengths for diffferent concentrattions of MB were meassured to con nstruct the calibra ation graph (Fig. 2). Witth the help o of the calibration graph, whe en the specctrophotomettrically w used, total obtained absorption values were b means o of the concentrattions were calculated by

eq quation A = (0.205.C) - 0.0139. Concentratio on va alues were converted i nto volumettric values in mm m3 using the mass andd density values that we ere ob btained via th he calibrationn graph. Folllowing the use of the equation S = VM M / MA.σ.NA A, where S is urface area, VM V is the sinngle increme ental capacitty, su MA A is the mole ecular weighht, σ is the surface s area of a single adsorrbed particlee, and NA iss the Avogad do onstant (16 6), surfacee area iss calculate ed, co representing quantitative rresults. The groups were coompared stattistically usin ng arison found a the Mann-Whitney U-test. The compa gnificant (p < 0.05) diffference betw ween the tw wo sig groups.

Res ults Microleakage results in mm3 are given in Ta able 1. The mean m volumees of apical leakage values we ere 3.309×10-4 mm3 foor MTA, 4.91 15×10-4 mm m3 for KM. A significant s sstatistically difference in akage volum me was fouund between n the groups lea (P < 0.05). Th he positive ccontrols demo onstrated hig gh ap pical microle eakage (meean: 24.186 6×10-4 mm m3; P < 0.001), while w no leakkage was de etected in th he egative control group. ne

Ta able 1. Evaluation of thhe furcal lea akage of MT TA an nd KM with volume measuurement technique. Volume measuremen nt Groups

No. teeth

(m mm3.10-3) Meean ± SD

MTA M

165 5 ± 1.26a

KM M

245 5 ± 1.17b

a,b

Figure 3.. Calibration n curve of methylene m b blue in different concentration ns

Dis scussion n A fu urcation ro oot perforation comp licates endodonticc treatmen nt and compromises c the prognosis if it is not repaired r pro operly. It is ccrucial area of root perforation does not beecome that the a infected, a and the perfo oration should be repaireed in a

Groups with significant diffferences are shown s with sup percripted lettters. tim mely manner if possiblee (17). Many restorativve ma aterials hav ve been u sed to rep pair furcatio on pe erforations in dentistryy (18). Varrious in vittro me ethods have e been usedd to compa are MTA wiith these materials (19-21). The majoritty of recenttly ublished data a dealing witth the use of o MTA in ro oot pu an nd furcal perrforations is based on in n vitro and in viv vo studies (2 22). Various leakage moddels have been b used to asssess the ability of maaterials to seal furcatio on pe erforations, including dyye dye extraction, 1 15

Furcation perforation and volume measurement method

penetration, fluid filtration, and bacterial leakage models (14); there are advantages and disadvantages to each. In this study, we used a volume measurement method. Comparing the volume measurement method with fluid filtration and dye extraction methods, the former technique has the advantages of a shorter time requirement, greater accuracy, changes that are not simply dependent on spectrophotometric readings, and the ability to calculate small volume using devices that are standard equipment in most laboratories. Additionally, the volumetric measurement method gives quantitative results. The materials used are important and may affect the study results. MTA (17), amalgam (23), calcium hydroxide (24), and glass ionomer cements (17, 25) are among the materials that have been tested for repairing furcation perforations. The quality of the repairs demonstrates the difficulty in repairing furcal perforations. Many factors can affect the repair, including the technique used, the material chosen, the physician’s ability, the clinical conditions, and the biocompatibility of the repair material (17, 26). Our found a significant (p < 0.05) difference between the MTA and KM groups. Any material or technique may have particular features that must be considered with its clinical use. MTA is a fine powder, composed primarily of tricalcium silicate, tricalcium oxide, tricalcium aluminate, and silicate oxide, that forms a colloidal gel on hydration that solidifies in approximately 3 h (27). Consequently, when used as a root repair material, although there is some moisture on the external surface of the periradicular tissues, to assure proper setting, the internal aspect of the root must also be moistened using a cotton pellet.

Kaya et al.

References 1. 2. 3. 4. 5. 6.

7. 8.

10. 11. 12. 13.

Conclusions 14.

Within the limitations of this study, MTA resulted in significantly less dye leakage than Ketac Molar Easymix using a volumetric measurement method. The volumetric method may be a good alternative for evaluating leakage because it includes most of the advantages of leakage studies and gives quantitative results.

15. 16.

17.

18.

American Association of Endodontists Glossary of Endodontic Terms. 2003; 7th ed; 2003. Ruddle CJ. Nonsurgical Endodontic Retreatment. In Cohen S, Burns RC (eds). Pathways of the pulp, 8th ed. St Louis: Mosby Inc., 2002:917. Alhadainy HA. Root perforations. A review of literature. Oral Surg Oral Med Oral Pathol 1994;78:368–74. Tuna D, Olmez A. Clinical long-term evaluation of MTA as a direct pulp capping material in primary teeth. Int Endod J 2008;41:273–8. Torabinejad M, Chivian N. Clinical applications of mineral trioxide aggregate. J Endod 1999;25:197–205. Sarı S, Sönmez D. Internal resorption treated with mineral trioxide aggregate in a primary molar tooth: 18 month follow-up. J Endod 2006;32:69–71. Islam I, Chng HK, Yap AU. Comparison of the physical and mechanical properties of MTA and Portland cement. J Endod 2006;32:193–7. Taifour D, Frencken JE, Beiruti N, van't Hof MA, Truin GJ. Effectiveness of glass-ionomer (ART) and amalgam restorations in the deciduous dentition: Results after 3 years. Caries Res 2002; 36: 437-44. Glasspoole EA, Erickson RL, Davidson CL. Effect of surface treatments on the bond strength of glass ionomers to enamel. Dent Mater 2002;8:454–62. Camps J, Pashley D. Reliability of the dye penetration studies. J Endod 2003;29:592-4. Barthel CR, Moshonov J, Shuping G, Orstavik D. Bacterial leakage versus dye leakage in obturated root canals. Int Endod J 1999;32:370-5. Oliver CM, Abbott PV. Entrapped air and its effect on dye penetration of voids. Endod Dent Traumatol 1991;7:135-8. Hashem AAR, Hassanien EE. ProRoot MTA, MTAAngelus and IRM used to repair large furcation perforations: sealability study. J Endod 2008;34:59-61. Hamad HA, Tordik PA, McClanahan SB. Furcation perforation repair comparing gray and white MTA: a dye extraction study. J Endod 2006;32:337–40. Aydın H, Baysal G. Adsorption of acid dyes in aqueous solutions by shells of bittim (Pistacia khinju stocks), besalination. 2006;196:248-59. Pathomvanich S, Edmunds DH. The sealing ability of Thermafil obtutarors assessedby four different microleakage techniques. Int Endod J 1996;29:327-34. Daoudi MF, Saunders WP. In Vitro Evaluation of Furcal Perforation Repair Using Mineral Trioxide Aggregate or Resin Modified Glass Ionomer Cement with and without the Use of the Operating Microscope. J Endod. 2002;28:512-5. Bryan EB, Woollard G, Mitchell WC. Nonsurgical repair of furcal perforations: a literature review. Gen Dent 1999;47:274–8.

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19. Nakata TT, Bae KS, Baumgartner JC. Perforation repair comparing mineral trioxide aggregate and amalgam using an anaerobic bacterial leakage model. J Endod 1998;24:184–6. 20. Hardy I, Liewehr FR, Joyce AP, Agee K, Pashley DH. Sealing ability of One-Up Bond and MTA with and without a secondary seal as furcation perforation repair materials. J Endod 2004;30:658–61. 21. Hashem AA, Hassanien EE, ProRoot MTA. MTAAngelus and IRM used to repair large furcation perforations: sealability study. J Endod 2008;34:59–61. 22. Pace R ,Giuliani V, Pagavino G. Mineral Trioxide Aggregate as Repair Material for Furcal Perforation: Case Series. J Endod 2008;34:1130– 3. 23. Grossman LI. The management of accidents encountered in endodontic practice. Dent Clin North Am 1957;2:11. 24. lmura N, Mie Otani S, Hata G, Toda T, Zuolo ML. Sealing ability of composite resin placed over calcium hydroxide an calcium sulphate plugs in the repair furcation perforation in mandibular molars: a study in vitro. Int Endod J 1998;31:7984. 25. Fuss Z, Szajkis S, Tagger M. Periodontal response to glass ionomer cement in treatment of furcation perforations in dogs. J Dent Res 1992;71:1031. 26. Nicholls E. Treatment of traumatic perforations of the pulp cavity. Oral Surg Oral Med Oral Pathol 1962;15:603–12. 27. Nicholls E. Treatment of traumatic perforations of the pulp cavity. Oral Surg Oral Med Oral Pathol 1962;15:603–12.

Review Article

Int Dent Res 2011;1:18-25

A Literature Review of Self Adjusting File Özkan ADIGÜZEL Assistant Professor, Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, Diyarbakır, TURKEY

Abstract Key Words Self-adjusting file, new rotary file, nickel-titanium, endodontic files Correspondence: Ozkan ADIGUZEL Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, 21280, Diyarbakir, TURKEY. e-mail: ozkanadiguzel@dicle.edu.tr

A primary aim of root canal treatment is to completely clean and shape the root canal system. Various instruments are available for endodontic instruemntation. Although rotary systems do prepare many canals without major procedural errors, they do not address canal types with long-oval or flat cross sections. A newly developed self-adjusting file (SAF) was designed to address the shortcomings of traditional rotary files by adjusting itself to the canal cross section. This instrument consists of a compressible opened NiTi tube that, on placement into a root canal, will exert pressure against the canal Wall. The SAF is used in an in-and-out motion powered by a handpiece and under constant irrigation. The aim of this review was to describe instrument design, usage parameters and features of Self Adjusting File. (Int Dent Res 2011;1:18-25)

Introduction The cleaning and shaping of the root canal system is an important objective of root canal treatment (1,2). Original root canal path should be maintained and the root canal wall dentin should be cut circumferentially so that prepared root canal wall outline reflects the original outline (1). The goal of instrumentation is to provide a continuously tapered preparation that maintains original root canal anatomy, keeping the foramen without any ledge and transportation from the original canal curvature (3,4). A variety of instruments are available for the root canal instrumentation. For many years, hand files are the most commonly used for endodontic instruments (5). Traditionally, this group of instruments has been manufactured from stainless steel and comprises two basic designs, the K-type instruments (K-files and K-reamers) and the Hedstrom file (5, 6). Although almost all these instruments were designed between many years

ago, important changes have introduced in recent years with regard to their quality, efficacy, and standardization (7). Nickel-titanium instruments for manuel and rotary use have been developed during the last decade (8). It was introduced to facilitate root canal instrumentation (8).

Nickel-Titanium Rotary Instruments Since the early 1990s, several endodontic instrument systems manufactured from nickeltitanium have been introduced into endodontic clinic practice. The specific design characteristics vary, such as tip sizing, taper, cross section, helix angle, and pitch. To date, several devices and methods have been used to perform endodontic treatment. The specific design characteristics vary, such as tip sizing, taper, helix angle, cross section (Fig. 1) (9), and pitch. New designs continually are produced (9).

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Fig gure 1. Cro oss-section designs of various nick kel titanium rotary instrruments (A)) Profile; (B B) Protaper; ((C) Hero; (D D) Race; (E) Quantec; (F F) K3. c rotary y file system ms may In flatt oval root canals, be difficullt to instrum ment the en ntire wall off oval canals and d often fail to adequately y clean and shape the canal (10). New endodontic e rotary r instru ments g cross-sectional mechanical design ns and of varying tapers ha ave been developed, targeting better cleaning a and shaping ability (11, 12, 13). Thee selfadjusting ffile (SAF) wh hich a new concept in cleeaning

nd shaping, was deveeloped to overcome o th he an inh herent rema aining probleems of the nickel-titaniu n um insstruments (1 14). The new concept andd technologie es continues to ch hange the dy ynamics of eendodontic practices in th he wo orld. Rapid and a significaant changes in technique es, insstrument design, and thhe type of metals m used to ma anufacture endodontic instrumentss have bee en

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made m during the last few years in an attempt to ov vercome can nal preparatio on errors (7)). This review attemptts to describ be factors th hat in nfluence sha aping outcom mes with SA AF file, such as in nstrument de esign, and ussage parame eters.

The Se elf-Adjustting file (S SAF) Design n and Ope eration usting file (Re-Dent-No ova, Ra’anan Self-Adju na, Issrael) which hollow file designed d is a novel systeem among the nickel-titanium files operating in a nner (Fig. 2). 2 It adapts itself to tthe different man

natomy and sshape, longitudinally to canal’s original an ved canal, ass will all rotaary nickel-tita anium files, a curv especcially differe ently adaptss itself to the crosssectio on of the canal, c providding three-d dimensional adapttation during g the cleaningg and shapin ng process. It is a hollow file designed ass a compresssible, thinwalled d pointed cylinder c eitheer 1.5 or 2.0 2 mm in diame eter compose ed of 120- m mm-thick nick kel-titanium lattice e (Fig. 3), composed of a thin derivate d of nickel-titanium latttice with higgh torsional and a fatigue resisttance (14).

Fiigure 2. Self Adjusting FFile

Fiigure 3. Holllow design o of Self Adjustting File

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The 1 1.5-mm and d 2.0-mm files may eassily be compresse ed to the extent e of be eing inserted d into canal pre eviously pre epared or negotiated with respectively a # 20 K-ffile and #30 K-file. The ffile will mpt to get back its original dimen nsions, then attem thus applyying a contin nually delicatte pressure o on the root canal walls. In a round r canal, it will get sh hape a w in an n oval or flatt canal round crosss-section, whereas it will gett shape a flat or oval cross-section c n. The lattice surrface is slig ghtly abrasiv ve and it allows removing dentin with h a back-a and-forth grrinding uring its ope eration, SAF file is design ned to motion. Du be compre essed while inserted into a narrow w root canal. The e file then attempts a to regain its o original dimensionss, it continue es to apply aperpetual a deelicate pressure o on the root ca anal walls (14, 15). The S SAF is opera ated with vertical (in and d out) vibrating h handpieces with w 3,000 to o 5,000 vibrrations

er minute and a an ampplitude of 0.4 0 mm KaV Vo pe GE ENTLEpower dental hanndpiece can n be used or sim milar combin ned with eitther a 3LDS SY head (36 60o fre ee rotation; Kavo, Biberaach Riss Germ many) (Fig. 4) or MK-Dent head (360o free rotation; MK-Den nt, argteheide, Germany) G orr RDT3 head d (Fig. 4) (8 80 Ba rpm when fre ee and stopss rotating when w engagin ng R va, the canal walls, newly devveloped by Re-Dent-Nov a’anana, Israel) (14). Ra The hollow designn SAF file e allows for f co ontinuous irrigation throuughout the procedure. p Th he irrrigation is performed continuously y during th he op peration used d a special irrrigation appa aratus (VATE EA Irrrigation Deviice, ReDent--Nova). A sp pecial irrigatio on de evice (Fig. 5) 5 is attacheed by a silico on tube to th he irrrigation hub on the shafft of the file e (Fig. 6) an nd provides contin nuous irrigattion flow at a low pressu ure nd at flow rattes of 1 to 100 mL/min. an

Figure e 4. KaVo GE ENTLEpowerr handpiece and a RDT3 he ead

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Figure 5.. VATEA Irrig gation Devicee

Figure 6.. VATEA Irrig gation Devicee with attach hed by silicon n tube on thee shaft of the e file

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During the operating procedure, the SAF is inserted into the root canal while vibrating and is meticulously pushed in until it reaches the measured working length. The SAF file is operated in two cycles of 2 minutes each for a total of 4 minutes per canal. It is performed with in-and-out manual motion and with continuous irrigation VATEA Irrigation Device, in this way allowing continuous fresh irrigant to be present in the canal during the procedure. This procedure is reported to remove a uniform dentin layer 60- to 75-mm thick from the root canal circumference. The SAF is removed from the canal for inspection after each cycle. Each SAF file is designed and recommended for single use (14). During the first minute of each cycle of 2 minutes, sodium hypochlorite (3%) is used as the root canal irrigant and EDTA (17%) is used during the second minute. The flow rate of the irrigants set at 5 mL/min, resulting in a total volume of 10 mL of each irrigant used during the procedure with additional activation of the irrigant by its vibrating motion. After two cycles, an additional irrigation with EDTA (17%) is used for 0.5 minutes with the vibrational mechanism turned off followed by a final short flush with sodium hypochlorite (3%, 5 mL) to remove the remaining EDTA (14).

Mechanical Analysis of SAF Compressibility of the SAF force applied as a result of compression, surface roughness, abrasivity test, durability (torque test, ada cyclic fatigue test, free buckling fatigue test, functional fatigue-tofailure test), SAF degradation as a function of working time and irrigation experiments mechanical analysis tests were conducted as previously reported by Hof et al.(15). It can be summarized as follows (15): a. The SAF file may be elastically compressed considerably from a diameter of 1.5 mm to dimensions resembling those of an ISO # 20 K-file because of the special design of the file. b. The SAF file creates circumferential force when initially compressed. c. The rough surface, combined with the force and the in-and out vibrational mechanism, allows for the removal of dentin by filing. d. The circumferential force and the ability to remove dentin decreases as the diameter of the canal enlarges. e. If the file is reused, the ability to remove dentin declines.

The SAF file is mechanically durable for continuous operation for 29 minutes. g. SAF application does not push the irrigant beyond the apical foramen.

Removal of the Smear Layer in the Apical Part of the Canal Debridement of the root canal system is important for endodontic success (16). Irrigants must be brought into direct contact with the entire root canal wall for optimal effectiveness and it was reported that enhancement of the flushing action is essential to improve root canal cleanliness (17, 18). As with any endodontic instrument, the SAF produces a smear layer on the root canal walls (19). This layer should be removed in order to provide the penetration of intracanal disinfectant into the dentinal tubules and also the complete adaptation of obturation materials to the dentin walls (17). Although sodium hypochlorite has been recommended as the main irrigant, it can not dissolve inorganic dentin particles (17). Irrigation with NaOCl in association with a chelating agent such as ethylenediaminetetraaceticacid (EDTA) citric acid have been recommended in endodontic therapy (17). Studies have shown that debris can remain in the root canal system after instrumentation and irrigation. However, scanning electron microscopic studies show that the removal of the smear layer and debris in the apical third of the root canal using either a syringe and a needle or a chelating agent leaves much to be desired (19). It was reported that when 3% sodium hypochlorite and 17% EDTA were used as irrigants with the SAF file, the root canal wall (including its apical third) was rendered clean of debris and the smear layer (19). It might be attributed to effective continuous substitute of the chelator in the apical third and to the mechanical vibrating action of the SAF in this region (14).

Root Canal Obturation of SAFprepared root canals Obturation of the root canal system has been performed using various techniques. Obturation of SAF-prepared root canals might be possible done by any of the obturation methods. Obturation using lateral compaction using chloroform-dipped customized master cones is reported. This technique has the advantage of providing visualize the shape of the SAF-treated root canals (14). Metzger et al reported that the self-adjusting files showed better

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cleaning and shaping and better adaptation of the root canal filling material (20).

Clinical Use A series cases with SAF treatment have been completed according to protocol as described by Metzger et al (14). It was reported in more than 100 clinical cases without any file seperation (14).

Conclusions The usage new concept of rotary nickeltitanium files adds a new quality to root canal preparation. SAF operated with continous flow of irrigation results in debris and smear free in most of the root canal walls. The SAF represents a new approach in endodontic rotary file design and operation. It contributes greatly to endodontic armamentarium. Its main features are as follows (14, 15, 19): 1. The SAF file is different from any nickeltitanium rotary file. It is claimed to adapt itself three-dimensionally to the shape of the root canal, including to adapt to its cross-section 2. One file is used during the procedure. 3. Canal straightening and canal transportation of curved canals are largely denied because of the lack of a rigid metal core. 4. High mechanical durability overcomes the mechanical failure of nickel-titanium instruments. 5. Hollow and flexible design allows continuous irrigation with constant refreshment of the irrigant throughout the procedure. 6. SAF file generates circumferential force. 7. It tends to keep the apical part of curved canals closer to its original location with no zipping. 8. SAF application with continuous irrigation does not push the irrigant beyond the apical foramen.

References 1.

Baugh D, Wallace J. The Role of Apical Instrumentation in Root Canal Treatment: A Review of the Literature J Endod, 2005;31(5):333-340 Bartha T, Kalwitzki M, Löst C, Weiger R. Extended apical enlargement with hand files versus rotary NiTi files. Part II. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2006 Nov;102(5):692-7.

6. 7. 8.

9. 10.

11.

12.

13.

14.

15.

16.

17. 18.

19.

Carvalho LA,, Bonetti I, Aurelio M, Borges G. A comparison of molar root canal preparatio n using stainless-steel and nickel-titanium instruments. Journal of Endodontics, 1999;25(12):807-10 Matwychuk M, Bowles W, McClanahan S, Hodges J, Pesun I. Shaping abilities of two different engine-driven rotary nickel titanium systems or stainless steel balanced-force technique in mandibular molars. J Endod. 2007;33:868–871. Walton RE, Torabinejad M. Principles and Practice of Endodontics. 2nd ed. Philadelphia, PA: Saunders; 1996. Wein FS. Endodontic Therapy. 5th ed. St Louis, MO: Mosby; 1996. Leif Tronstad. Clinical Endodontics, A Textbook.. 2nd ed. Thieme, New York; 2003. Yoshimine Y, Ono M, Akamine A. The shaping effects of three nickel-titanium rotary instruments in simulated S-Shaped canals. J Endod 2005;31:373-5. Hargreaves KM, Cohen S. Patways of the pulp. 6th ed. Mosby, 2006. Wu M-K, Wesselink PR. A primary observation on the preparation and obturation in oval canals. Int Endod J 2001;34:137–41. Yao JH, Schwartz SA, Beeson TJ. Cyclic fatigue of three types of rotary nickeltitanium files in a dynamic model. J Endod 2006;32:55–7. Peters OA, Paque F. Current developments in rotary root canal instrument technology and clinical use: a review. Quintessence Int. 2010 Jun;41(6):479-88. Review. Ersev H, Yılmaz B, Çiftçioğlu E, Özkarslı ŞF. A comparison of the shaping effects of 5 nickel-titanium rotary instruments in simulated S-shaped canals. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e86-e93 Metzger Z, Teperovich E, Zary R, Cohen R, Hof R. The self-adjusting file (Saf). Part 1: Respecting the root canal anatomy - a new concept of endodontic files and its implementation. J Endod 2010;36:679–90. Hof R, Perevalov V, Eltanani M, Zary R, Metzger Z. The self-adjusting file (Saf). Part 2: mechanical analysis. J Endod 2010;36:691–96.Sdf Siqueira JF Jr, Rocas IN. Clinical implications and microbiology of bacterial persistence after treatment procedures. J Endod 2008;34:1291–301. Zehnder M. Root canal irrigants. J Endod 2006;32:389–98. Rödig T, Döllmann S, Konietschke F, Drebenstedt S, Hülsmann M. Effectiveness of different irrigant agitation techniques on debris and smear layer removal in curved root canals: a scanning electron microscopy study. J Endod. 2010;36(12):1983-7. Metzger Z, Teperovich E, Cohen R, et al. The Self-adjusting File (SAF). Part 3: Removal of

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Debris and Smear Layer—A Scanning Electron Microscope Study. J Endod 2010;36:697–702. 20. Metzger Z, Zary R, Cohen R, Teperovich E, Paqué F.The quality of root canal preparation and root canal obturation in canals treated with rotary versus selfadjusting files: a three-dimensional microcomputed tomographic study. J Endod. 2010;36(9):1569-73.

Review Article

Int Dent Res 2011;1:26-31

Contemporary Permanent Luting Agents Used in Dentistry: A Literature Review Ebru SÜMER1, Yalçın DEĞER2 1 2

Assistant, Dicle University, Faculty of Dentistry, Department of Prosthodontics, Diyarbakır, TURKEY Assist. Prof., Dicle University, Faculty of Dentistry, Department of Prosthodontics, Diyarbakır, TURKEY

Abstract Key Words Dental cements, luting agents, adhesive resin cement, resin modified glass ionomer cement. Correspondence:

Ebru SÜMER Dicle University, Dental Faculty, Department of Prosthodontics, 21280 Diyarbakir, Turkey e-mail: dt_ebrusumer@hotmail.com

Dental cements are widely used in dentistry. Base material, temporary filling material and luting agents can all have different clinical applications. Different types of cement have also been developed for various orthodontic and endodontic treatments. In literature it is still argued that there is not ideal cement answering all purposes yet, so different materials are required for the comprehensive patient treatments and it is not always that easy to make the best choice. The aim of this article is to provide a clinically relevant discussion of contemporary permanent luting agents, in order to enhance the dentist’s ability to make proper cementation choices and application. (Int Dent Res 2011;1:26-31)

Introduction Dental cements are widely used in dentistry. They can all have different clinical uses in dentistry. Cements can be used as base material, temporary filling material and luting. There are also different types of cements developed to be used in orthodontic and endodontic treatments (1). Cements used as base material protect pulp from thermal, electrical and chemical effects (1, 2). Cements are used as temporary filling material cover the cavity hermetically and protect the tooth from external effects till the next clinic seance. Luting cements are used in adapting the tooth to indirect restorations prepared out of mouth (2). Luting agents may be permanent or temporary, depending on their physical properties and the planned longevity of the restoration (3). In literature it is still argued that there is not ideal cement answering all purposes yet, so different materials are required for the comprehensive patient treatment and it is not always that easy to make the best choice (4). 26

Zinc phosphate, zinc oxide eugenol and silicophosphate cements were used from the early twentieth century till 1970s when new cements were developed. At first polycarboxylate cement, next glass ionomer cements and within the last thirty years resin cements and resin modified glass ionomer cements were developed (5).

Qualities of Ideal Cement Basic mechanical, biological, and handling requirements must be met by the cement (2, 3, 6, 7): 1. It should be well adapted to living dental tissues, it should contain no pulp irritating toxic material and it should further have anticariogenic qualities, 2. It should have very low resolution ratios within the liquids inside the mouth, 3. In order to reach the smallest details between restoration and tooth, it should possess low viscosity and film thickness,

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4. It should be resistant against mastication forces and pulling forces formed through the effect of gummy foods, 5. It should have sufficient light transparency, 6. It should provide sufficient heat insulation to protect living tooth from thermal effects, 7. It should give sufficient working time and be easy to manipulate, 8. It should be able to bond to hard dental tissues, 9. It should have a long shelf-life. Ensuring optimal resistance and retention in tooth preparation has primary importance but still the cement should act like a barrier against microbial leakage, it should completely fill the tooth and restoration interface and protect the bond between restoration and tooth against mechanical and chemical effects (6). All the permanent luting cements on market have these qualities to some extent, but each type of cement displays different physical attributions with respect to their own substance (3).

Retention and Bonding Mechanical interlocking with rough surfaces on a parallel wall preparation is the principal means of retention for luting cement, regardless of chemical composition (3). Luting mechanisms of cements are three types; chemical, mechanical and micromechanical. Retention of restoration is obtained, depending on the quality of applied cement, through combining two or three of these mechanisms (8).

Classification Cements are mostly in the form of powder and liquid and their setting reaction is an acid-base reaction. Liquid acts like acid and powder acts like base. Aside from resin cements composed after polymerization of macromolecules, these cements that are set through acid-base reaction are classified as acid-base cements (AB Cements) (3). The literature varies considerably on the classification and discussion of cements. Craig followed a traditional classification that grouped cements with respect to their chief ingredients (ie, zinc phosphate, zinc silicophosphate, zinc oxideeugenol, zinc polyacrylate, glass-ionomer and resin), whereas O’Brien classified dental cements by matrix bond type (ie, phosphate, phenolate, polycarboxylate, resin and resin modified glass ionomer). Donovan simply divided cements into conventional (zinc phosphate, polycarboxylate, glass-ionomer) and contemporary (resin-modified glass-ionomers, resin) based on knowledge and experience using these materials (Table 1) (1, 3). International Dental Research © 2011

CONTEMPORARY PERMANENT LUTING AGENTS Resin Modified Glass Ionomer Cements Despite the positive aspects of glass ionomer cements that have been used in dentistry since the seventies till present day, in order to improve some of their qualities and eliminate the disadvantages, resin modified glass ionomer cements (RMGIC) were developed in the late eighties by adding resin into glass ionomer cements (2,3). Their contents are basically 80% glass ionomer cement and 20% resin and there may be some changes with respect to differences in brand. HEMA of which liquid is polymerized via light (Hydroxy ethyl methacrylate), methacrylate groups (EGMA, GMA and Bis-GMA etc.), tartaric acid, polyacrylic acid and water. Its powder however contains fluoro aluminosilicate glass particles. The qualities of resin modified glass ionomer cement are between conventional glass ionomer cements and composite resins which means RMGIC is a hybrid material (2). The polymerization of methacrylate units in cement can start with light or chemically (6). In dual cure materials HEMA’s polymerization starts with light activation and slower progressing acid base reaction continues to better strengthen the material and increase the resistance. In tricure materials however there is a chemical indicator for HEMA and HEMA’s polymerization starts chemically, next a matrix strengthened via progressive acidbase reaction takes place (2, 9). Compared to dual cure cements, the advantages of cements with tricure setting mechanism are the extra chemical polymerization of resin and the occurrence of polymerization in the places where light cannot reach (2). In the set cement there are two matrixes within each other. One is ionic matrix formed through acid-base reaction and the other one is resin matrix (10). These cements have compressive and diametral tensile strengths greater than zinc phosphate, polycarboxylate and some glass ionomers but less than resin composite. Their adhesion to enamel and dentin, and their fluoride release pattern is similar to glass ionomer cements (6). Due to the carboxyl groups in the polyalcenoic acid within them, RMGIC contain adhesive features (9). On that account there is no need for a bonding agent between the tooth and material (10). Applying dentine polyacrylic acid conditioner prior to RMGIC application not only improves wettability of dental surface but it also enables

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hydrogen bond formation and strengthens the cement and ionic change (10). Their abrasion resistance and fracture resistance are greater than GICs (Glass Ionomer Cements) and (20) they have better aesthetical features than GICs (2). Compared to GICs these cements are more resistant against water contamination during setting reaction and have low level of solubility. Another advantage of resin modified glass ionomer cements is their ease of mixing and use, because multiple bonding steps are not required. They also have adequately low film thickness (6). In resin ionomer cements, moving the excess cement after cementation constitutes a great problem. Therefore soon after the primary setting reaction, unreacted materials below restoration margins need to be cleaned (3). In these cements, resin addition has not significantly lowered dehydration resistance of glass ionomer content. Besides the most important disadvantage of resin ionomers is that due to polyHEMA with hydrophilic character water absorption, plasticity and hygroscopic expansion are increased. Water absorption in the beginning lessens the stress during polymerization shrinkage but water absorption that continues creates a harmful effect. As it displays significant dimensional changes, these cements are not applicable to use in full ceramic feldspathic-type restorations and post cementation (6, 9). Resin ionomers can be used in cementation of metal, metal-porcelain, crown and bridges, supporting amalgam, composite and glass ionomer cores as well as base material under composite fillings. They have different types developed for orthodontic applications as well (5, 6). Resin modified glass ionomer cements are available in the market as powder-liquid and automix capsule (5).

Polyacid Modified Composite Resin Cements Resin addition to conventional glass ionomer cements pioneered the development of a different group of luting cements. This group is somewhere between classical GICs and composite resins (3). Polyacid modified composite resins were defined at the end of 1990s as a composite of (compomer) composite resin (comp) and glass ionomer (omer) (3). Physical qualities of compomers are closer to composite resins (11). The material which at first is polymerized through light then meets water absorption in mouth and similar to chemical GICs, they set at the end of acid-base reaction (10). However since in compomers no salt matrix and hydrogel are formed (in glass ionomer cements with the effect of water 28

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that emerges when acid-base reaction starts salt matrix containing the salts of polycarboxylic acid is formed and the surface of glass particles turns into silica hydrogel) they cannot act like fluoride reservoir hence their fluoride release is restricted (2). Without etching process, only with their unique bonding agents, they bond to the hard tissue of tooth and release fluoride to the adjacent dental tissues (10). Their compressive and flexural resistance is greater than RMGICs but lower than composite resins. Without applying bonding agent, adhesion of compomers to tooth is limited (3). Bonding agent within sets of compomers are mostly one-phase bonding systems that combine primer and adhesive mostly in one single bottle (2).

Resin Cements Resin cements are one type of composite consisting of resin matrix and filler inorganic particles (9). The bonding between resin matrix and fillers are created via inter phase agent. This inter phase agent consists of long chain molecule silanes of which organic silica component. That means resin cements consist of three phases that are structurally different; organic phase, inorganic phase and inter phase (10). With the lower filling structure and viscosity in their context, they differ from restorative composites (9). In a good number of resin cements, there are glass or silica particles varying between the ratios of 20%-80% (3). Silica particles strengthen mechanical qualities of mixture, they permeate and diffuse the light (10). These fillers make it possible that cement is more resistant against compressive and tensile forces and perform low solubility (6). With respect to filler size, composite resin cements are classified into two groups as with micro filler (about 0.04 µm) and hybrid composites (about 0.7-1.7 µm) (21). In-vitro researches analyzed the effect of filling particles inside resin cement on the physical attributions of cement. It has been detected that compared to resin cements containing hybrid type filler, resin cements with micro fillers have greater resistance against wear (22). Biological compatibility and physical qualities of resin cements do not only depend on the quality and quantity of varying polymer and inorganic materials inside, but they are also closely related to the curing mechanism of resin (12). Resin cements can be activated chemically or via visible light or by both chemical and light (dual cure). They have a variety of types in different colors and opacities (6). Amongst them the most ideal one is, with respect to polymerization conditions, light + chemical curing system (18). Resin cements that are chemically polymerized have been produced in double paste system or in the form of powder-liquid. Polymerization starts IDR — Volume 1, Number 1, 2011

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chemically by mixing two components. In paste system, in one of the paste there is benzoyl peroxide initiating polymerization and in the other one there is tertiary amine speeding up polymerization. Resin cements that are polymerized with light have been produced in single paste system. In these cements, as light absorber, there is camphorquinone and as accelerator there is aliphatic amine. Dual cured resin cements have been produced as two paste or in powder-liquid form. In their structure there is both a polymerization starter (camphorquinone) and chemical activator components (peroxytamine) (10). Due to their chemical structures they provide adhesion with tooth tissues. The bonding of resin to enamel is achieved through micromechanical interlocking of resin to hydroxyapatite crystals and acidic enamel prisms. Bonding to dentin is however more complex; it is achieved through penetration of hydrophilic monomers to partially demineralized apatite structure of etched dentin. Hence adhesion is created via micromechanical interlocking of resin to hybrid layer or resin diffusion zone (6, 9). Bonding to dentin requires multiple phases. Since total etching systems frequently cause postoperative sensitivity, less invasive self etching systems have been developed. Through the application of self etching systems, the number procedures to follow decreases (13, 22). Polymerization shrinkage of resin cements may bring about invasive stresses in the tooth and restoration interface. If thin cement layer cannot stand high stresses, there may be a break in bonding. By applying dentin bonding agents a hermetic cover is created between resin and tooth structure, postoperative sensitivity is prevented and adhesion is strengthened (13). Resin cements chemically bond to etched, silane-treated porcelain. One part of resin cements is bonded to the surface of prepared tooth and one part is bonded to etched and silane-treated porcelain so the stress on tooth is diffused. Based on a good number of laboratory and clinical researches, it can be suggested that resin cements are the best choice for the cementation of full ceramic restorations (3, 9). Furthermore resin cements can form a better bonding with metal alloys sanded via micromechanical retention (6). Certain resin cements contain ytterbium trifluoride and can make some amount of fluoride releasing. Some, on the other hand contain fluorosilicate fillers. Still resin cements lack any fluoride releases with significant level (6). Film thickness may be relatively greater than the other cements. Pulpal biocompatibility however may be particularly problematic in deep penetrations. Resin cements necessitate more sensitive techniques than

International Dental Research ÂŠ 2011

Contemporary Luting Agents

conventional cements and they have higher costs (3). In situations where there is no optimal retention and resistance in preparation, resin cements are more useful than conventional cements (6). Particularly in cementation of full ceramic crown restorations or metal-fused restorations prepared for conic cut or short clinic crown long tooth surfaces, resin-based luting cements are preferred more and these cements are advantageous in the other undesired geometric configurations as well (14). The ability of luting multiple structures together, high resistance, less solubility inside mouth, and color options make resin cements an alternative cement in luting aesthetical restorations (6,19). They can be used in cementation of composite inlays and onlays, full ceramic inlays and onlays, veneers, crowns, bridges and fiber-forced restorations. Resin cements that are polymerized chemically are recommended for the cementation of resin bonded bridges (Maryland type) (6) and ceramic crowns inhibiting light penetration (10). Resin cements that are polymerized via light are used in luting ceramic or composite laminates that allows full penetration of visible light, with thickness less than 1,5-2 mm and having translucent structure (10). Dual cured resin cements are used in restorations where restoration is translucent only enough to allow the penetration of little light but with a thickness (more than 1,5-2 mm) that does not allow polymerization with light only (10).

Adhesive Resin Cements Today many of the resins that are termed as adhesive are not actually with adhesive attributions. Only adhesive resins with monomers containing 4META and MDP have adhesive quality (9). In the early 1980s, conventional Bis-GMA resin cement was modified by adding a phosphate ester to the monomer component, introducing to dentistry a unique group of resin luting agents that have a degree of chemical bonding as well as a micromechanical bonding to tooth structure and base metal alloys. The first product marketed, Panavia, contained the bifunctional adhesive monomer MDP (10-methacryloyloxydecyl dihydrogen phosphate) and was a powder-liquid system (3). Bond strength to etched base metal greatly exceeded that to tooth and Panavia quickly became the luting agent of choice for resin retained fixed partial dentures (3). In 1994, Panavia was modified to include a dentin/enamel primer containing hydroxethyl methacrylate (HEMA), N-methacryloyl 5aminosalicylic acid and MDP, intended to improve bond strength to dentin. Under a new name, Panavia 21, it was marketed as a two-paste system 29

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that offered three shades: tooth colored (TC, translucent), white (EX, semitranslucent), and opaque (OP). Panavia 21’s polymerization required exclusion of oxygen, and a covering gel was provided. The current product, Panavia F is a twopaste system that is dual-cured, self-etching and self-adhesive, plus fluoride-releasing (3). Before the introduction of Panavia, Bis-GMA composite was modified by decreasing filler and adding %3 2-hydroxy-3b-napthoxypropyl methacrylate in methyl methacrylate with 4methacryloyloxyethyl trimellitate anhydride (4META) and tri-n-butyl borane and marketed as C&B Metabond (3). C&B Metabond has physical characteristics similar to other resin cements, but also has an extremely high tensile strength, which is useful for providing retention in restorative situations where less than optimal conditions exist.

It is a powder/liquid auto-curing system and may be used for resin bonded prostheses (23). Panavia and C&B Metabond represent several available unique adhesive resin luting agents of various compositions that can help provide adequate retention for crowns and prostheses where less than ideal retention exists (3). The strong cohesion forces in the specific net structure of adhesive resin allow a better stress distribution on the surface of restored tooth (10). These materials are usually expensive and demand sensitive technique, difficult to clean up when set, and they have no long shelf lives (6, 17).

Table 1. Varieties of contemporary permanent luting agents Cement Type

Resin Modified Glass Ionomer Luting Cement

Polyacid Modified Composite Resin Cement

Resin Cement

Adhesive Resin Cement

Product

Company (Location)

Vitremer Luting Cement

3M Dental Products, USA

Fuji Plus

GC Dental Industrial Corp, USA

Fuji II LC

GC Dental Industrial Corp, USA

Fuji Ortho LC

GC Dental Industrial Corp, USA

Photac Fil

3M ESPE, USA

Photac Bond

3M ESPE, USA

Pro Tec Cem

Ivoclar, Vivadent, Liechtenstein

Dyract CEM plus

Dentsply, USA

Variolink II

Ivoclar, Vivadent, Liechtenstein

Ultra-Bond Plus Resin Cement

Den-Mat, Santa Maria

Duo-Link

Bisco, USA

C&B Cement

Bisco, USA

RelyX Unicem

3M ESPE, USA

RelyX U100

3M ESPE, USA

RelyX ARC

3M ESPE, USA

Panavia F 2.0

Kuraray, Japan

Panavia 21

Kuraray, Japan

C&B Metabond

Parkell, USA

Clearfil SA Cement

Kuraray, Japan

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Conclusion

Restorative dentistry has been going through continuous changes as an outcome of clinical applications and development of new materials. Modern dentistry have a wide variety of application products differing from each other in content and physical attributions (5, 8). Therefore it may pose difficulty for dentists to make a choice amongst so many alternative products (15). Presently there is a rapid development in aesthetical restorative materials and adhesive systems enabling these materials to bond on tooth (18). Modern dentistry services which can no longer be provided through conventional water based luting cements have become diversified due to the advantages of adhesive techniques (10). A 2001 survey indicated that many clinicians are now exclusively using newer resin-modified glass-ionomer and resin luting materials based primarily on ease of use, reasonable retention, and low to no postoperative sensitivity (3). However conventional cementation and adhesive cementation are, let alone being conflicting, complementing each other. The choice should be based on the type and design of planned restoration because none of the present products possesses all qualities of an ideal luting agent (10). Each cement type has different physical, mechanical and biological features arising from its own chemical structure. That is why one single cement type alone is not sufficient for daily clinical applications. To achieve a clinical success, any clinician is expected to be aware of the qualities, advantages and disadvantages of each type of cement and conduct their clinical applications.

6. 7. 8. 9.

10. 11. 12. 13. 14.

15.

16. 17. 18.

19.

References 1. 2.

3. 4.

McCabe JF, Walls AWG. Applied Dental Materials. 9th edition. Oxford: Blackwell Publishing; 2008. p. 257-288. Önal B.Simanlar. Restoratif Diş Hekimliğinde Maddeler ve Uygulamaları.1st edition. İzmir: Ege Üniversitesi Dişhekimliği Fakültesi Yayınları; 2004. p.1-145. Hill EE. Dental cements for definitive luting: a review and practical clinical considerations. Dent Clin N Am 2007; 51:643-658. Rosenstiel SF, Land MF, Crispin BJ. Dental luting agents: A review of the current literature. J Prosthet Dent 1998; 80:280-301.

20. 21. 22. 23.

O’Brien WJ. Dental materials and their selection. 3rd edition. Canada: Quintessence Publishing; 2002. p.132-154. Diaz-Arnold AM, Vargas MA, Haselton DR. Current status of luting agents for fixed prothodontics. J Prosthet Dent 1999; 81:135-141. Aydın M,Gür H.Sabit Protezlerde Simantasyon. Dişhekimliği Klinik Dergisi 1997; 10(4):239-243. Pegoraro TA, Da Silva NRFA, Carvalho RM. Cements for use in esthetic dentistry. Dent Clin N Am 2007; 51:453-471. Eskimez Ş, İzgi AD. Rezin Simanlar. Adeziv Köprüler ve Klinik Uygulamaları.1st edition. İstanbul: Quintessence Yayıncılık; 2008. p.149160. Zaimoğlu A, Can G. Sabit Protezler. Ankara: Ankara Üniversitesi Diş Hekimliği Fakültesi, 2004.p.239-267. Guggenberger R, May R, Stefan KP. New trends in glass-ionomer chemistry. Biomaterials 1998; 19:479-483. Attar N, Tam LE, McComb D. Mechanical and physical properties of contemporary dental luting agents. J Prosthet Dent 2003; 89:127-134. Öztürk AN, Aykent F.Dentin Bonding Ajanlar ve Simantasyon. Cumhuriyet Üniversitesi Dişhekimliği Fakültesi Dergisi 2001;4(2):128-131. Levent H, Oruç AZ. Rezin esaslı yapıştırma simanları ile yapıştırılan metal destekli kronlarda mikrosızıntının değerlendirilmesi. GÜ Dişhek Fak Derg 2004;21(1):19-22. Paradella TC. Current adhesive systems in dentistry – what is being said and researched. Odontologia. Clín.-Científ., Recife 2007; 6 (4): 293-298 . 16. Milutinovic-Nikolic AD, Medic VB, Vukovic ZM. Porosity of different dental luting agents. Dental Materials 2007;23:674-678. Baydaş S. Kron-Köprü Protezleri. Erzurum: Özyurt Matbaacılık; 2005.p.127-133. Akören AC, Üçtaşlı S. Farklı Porselen İnley Sistemleri ve Farklı Yapıştırma Simanlarının Mikrosızıntı Üzerine Etkileri. T Klin J Dental Sci 1998;4:100-105. Miguel A, Macorra JC, Nevado S, Gomez J. Porosity of resin cements and resin-modified glass-ionomers. Am J Dent 2001; 14:17-21. Smith DC. Development of glass-ionomer cement systems. Biomaterials 1998;19:467-478. Shinkai K, Suzuki S,Katoh Y. Effect of filler size on wear resistance of resin cement. Odontology 2001;89:41-44. Christensen GJ. Should resin cements be used for every cementation? Journal of ADA 2007; 138:817-819. Ertuğrul HZ, Ismail YH. An in-vitro comparison of cast metal dowel retention using various luting agents and tensile loading. J Prosthet Dent 2005; 93(5):446-452.

Review Article

Int Dent Res 2011;1:32-37

Diagnosis and Treatment Modalities of Internal and External Cervical Root Resorptions: Review of the Literature with Case Reports Senem YİĞİT ÖZER Assistant Professor, Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, Diyarbakır, TURKEY

Key Words Internal cervical root resorption, external cervical root resorption, cone beam computed tomography, CBCT, differential diagnosis, resorptive defect Correspondence:

Senem YİĞİT ÖZER Dicle University, Faculty of Dentistry, Department of Operative Dentistry and Endodontics, 21280, Diyarbakir, TURKEY. e-mail: senemygt@hotmail.com

Abstract The clinical presentation of internal and external cervical lesions vary considerably, and detection of lesions is often made incidentally. Accurate diagnosis is the most important step of the treatment plan because these pathologies are quite different from each other concerning their treatment procedures. This paper gives a literature review of internal and external root resorptions with respect of their etiology and adresses the difference in treatment modalities. (Int Dent Res 2011;1:32-37)

Introduction Diagnostic information directly influences clinical decisions. Accurate data lead to better treatment-planning decisions and potentially more predictable outcomes. Cone beam computed tomography (CBCT) is an innovative technology that offers the clinician clinically relevant information that cannot be gathered from conventional radiography (1). The ability to assess an area of interest in 3 dimensions eliminates the superimposition that is inherent in conventional radiographic imaging (2). Intraoral radiography produces images that have objects superimposed upon each other. The observer has to make 3-D decisions on the basis of a 2-D film (3). CBCT technology provides the clinician with the ability to observe an area in 3 different planes (axial, sagittal, and coronal) and thus acquire 3-D information. The axial and sagittal views are of particular value, and they are not seen with conventional periapical radiography (4). The

ability to reduce or eliminate superimposition of the surrounding structures makes CBCT superior to conventional periapical radiography (5). Specific endodontic applications of CBCT are being identified as the technology becomes more prevalent. Potential endodontic applications include diagnosis of endodontic pathosis and canal morphology, assessment of pathosis of non-endodontic origin, evaluation of root fractures and trauma, analysis of external and internal root resorption and invasive cervical resorption, and presurgical planning (1). Treatment of root resorptions (RR) can be complex and misdiagnosed. Imaging is critical to accurate diagnosis and appropriate treatment. Classically, Gartner et al (6) described the radiographic features of internal and external resorption. Off-angle radiographs have proven to be useful in differentiating these entities. The use of parallel radiographic techniques is advocated for differentiating internal from external resorption defects (6-8). A second radiograph taken at a different angle often confirms the nature of the resorptive lesion. External RRs will move in the same

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Internal and External Cervical Root Resorptions

direction as the x-ray tube shift if they are lingually/palatally positioned. Conversly they will move in the opposite direction to the tube shift if they are buccally positioned. Internal RRs should remain in the same position relative to the canal in both radiographs. Radiologically, internal RRs present as a cloudy, mottled, radiopaque lesion with irregular margins as a result of the presence of metaplastic hard tissue deposits within the canal space. Differentiating internal RR from external RRs might be clinically challenging, especially if the metaplasia has occupied the entire resorptive cavity. Diagnostic accuracy based on conventional and digital radiographic examination is limited by the fact that the images produced by these techniques only provide a 2-dimensional representation of 3dimensional objects (8-10). In addition, the anatomic structures being imaged might be distorted (11). This might lead to misdiagnosis and incorrect treatment in the management of internal and external root resorptions. Conventional radiography does not provide a true and full representation of the lesion. Conventional radiography is often unable to identify the true extent, location, or the portal of entry of a resorptive lesion. CBCT has been shown to help determine treatment complexity as well as aid the clinician in offering an accurate prognosis on the basis of the extent of the resorptive lesion (12). As a result, both treatment and treatment outcomes are likely to become more predictable.

Internal Root resorption Internal root resorption has been reported as early as 1830 (13). Compared with external root resorption, internal root resorption is a relatively rare occurrence, and its etiology and pathogenesis have not been completely understood (14). Nevertheless, internal root resorption poses diagnostic concerns to the clinician because it is often confused with external cervical resorption (7, 15, 16). Incorrect diagnosis might result in inappropriate treatment in certain cases (17). Once internal root resorption has been diagnosed, the clinician must make a decision on the prognosis of the tooth. If the tooth is deemed restorable and has a reasonable prognosis, root canal treatment is the treatment of choice. The aim of root canal treatment is to remove any remaining vital, apical tissue and the necrotic coronal portion of the pulp that might be sustaining and stimulating the resorbing cells via their blood supply, and to disinfect and obturate the root canal system (18). Internal root resorption lesions present the endodontist with unique difficulties in the preparation and obturation of the affected tooth.

Access cavity preparation should be conservative, preserving as much tooth structure as possible, and should avoid further weakening of the already compromised tooth. In teeth with actively resorbing lesions, bleeding from the inflamed pulpal and granulation tissues might be profuse and might impair visibility during the initial stages of chemomechanical debridement. The shape of the resorption defect usually renders it inaccessible to direct mechanical instrumentation. The primary objective of root canal treatment is to disinfect the root canal system. This is followed by obturation of the disinfected canal with an appropriate root-filling material to prevent it from reinfection. By their very nature, internal root resorption defects can be difficult to obturate adequately. To completely seal the resorptive defect, the obturation material should be flowable. Gutta-percha is the most commonly used filling material in endodontics. Gençoğlu et al (19) examined the quality of root fillings in teeth with artificially created internal resorptive cavities. They found that the Microseal (Sybron Endo, Orange, CA) and Obtura II (Spartan, Fenton, MO) thermoplastic gutta-percha techniques were significantly better in filling artificial resorptive cavities than Thermafil (Dentsply, York, PA), Soft-Core core systems (CMS Dental, Copenhagen, Denmark), and cold lateral condensation (CLC). The cold lateral compaction technique produced slightly fewer voids than Obtura II, but a larger proportion of the canal space was filled with sealer with this technique. Goldman et al (20) also concluded that the Obtura II system performed statistically better in obturating resorptive defects than cold lateral compaction, Thermafil, and a hybrid technique. Stamos and Stamos (21) reported 2 cases of internal root resorption in which the Obtura II system was used to successfully obturate the canals. Similar results were reported by others (22). In situations when the root wall has been perforated, mineral trioxide aggregate (MTA) should be considered the material of choiceto seal the perforation. MTA is biocompatible (23) and has been shown to be effective in repairing furcation perforations (24) and lateral root perforations (25). The material is well-tolerated by periradicular tissues and has been shown to support almost complete regeneration of the periodontium (24). In addition, MTA has superior sealing properties when compared with other materials (26). A hybrid technique might also be used to obturate canals; the canal apical to the resorption defect is obturated with gutta-percha, and then the resorption defect and associated perforation are sealed with MTA (27, 28). When internal resorption has rendered the tooth untreatable or unrestorable, extraction is the only treatment option.

In nternal and Exxternal Cervica al Root Resorp ptions

Case forr Internal Resorptiv ve Defectt In the cconventional periapical ra adiography, an in nternal resorptive defecct was dete ected on rig ght mandibular m ce entral incisorr (Fig. 1A). However H the 2D im mage was insufficient to t provide adequate daata about the exa act localizatio on of the de efect whetheer it was w on the buccal or palatinal aspect. Accuraate trreatment pla an was not decided wh hether the ro oot ca anal obturation would be perform med using an in njectable wa arm gutta-p percha techn nique or M MTA application affter a surgiccal flap elev vation. A CB BCT performed and the sagittal s imaage sccan was p demonstrated d the extentt of an inte ernal resorpttive minimal residu ual root thick kness (Fig. 1 B). defect with m

Yiğit Özer

atment plan that minimizzes condenssation force A trea seemed prudentt to prevennt root fra acture and equent treatm ment failure.. In addition, a surgery subse includ ding a full mucoperiostal m l flap to acce ess directly to the e defect area a was prevennted. Root canal dentin was thin howeve er intact renndering a non-surgical n oach withou ut flap eleevation. CB BCT image appro evaluation exactly y determinedd the treatme ent plan. In I 1973, Frank and Weeine (29) described d a techn nique for the e repair of a perforation caused by intern nal resorption. Calcium hhydroxide was w used to effectt lateral perriodontal reppair, creating g a matrix against which to obtuurate. “Co onsiderable conde ensation” was required too fill the defe ect.

Figure 1. (A A) Conventional periapica al radiograph hy indicates internal roott resorption and the borders of the defect are we ell determine ed however this image caan not provid de detailed in nformation aabout the boundaries of he lesion forr the buccal and palatin nal aspects; (B) CBCT im mage on the e sagittal plaane indicates that root th dentin on the e buccal is ve ery thin but still intact. T The remaine ed tooth stru ucture enablee clinician to o use warm gutta-percha obturation te echnique witth a non-surg gical treatme ent approach.

Extternal Roo ot Resorp ption External root reso orption can n be furth her cllassified in nto surfacce resorption, exterrnal in nflammatory resorption n, external replacemeent re esorption, external cervical c ressorption, aand trransient apiccal breakdow wn (30). On ne of the leeast understood o of the typess of externa al resorption n is xternal cervvical resorpttion (ECR). This form of ex ex xternal resorrption has been describe ed at length by Heithersay H (31-34), who preferred p the e term invassive

34 3

n, which desscribes its in nvasive and cerviccal resorption aggre essive nature e. Other teerms used to t describe ECR include odontoclastoma ((35), periphe eral cervical ption (36), extracanal e innvasive resorrption (17), resorp supra aosseous exttracanal invvasive resorp ption (37), periph heral inflammatory roott resorption (38), and subep pithelial exte ernal root resorption (39). ECR usually occurs immediately below the e epithelial hment of the e tooth at thhe cervical region r (40) attach and ECR defectts are difficcult to diag gnose and mana age. IDR — Voolume 1, Number 1, 2011

Yiğit Özer

Treatment depen nds on the severity, loccation, h perforate ed the root canal whether tthe defect has nd the resto orability of the t tooth. S Several system, an treatment regimes have been suggested s i n the ature of thee ECR literature, depending on the na nd are usua ally based on isolated case lesion, an reports. Th hese include e intentional replantation n (41), guided tisssue regenerration (42), treating thee ECR lesion by a an internal approach a only y (37), and fforced orthodontic eruption (38). Esse entially, treaatment moval of the e resorptive tissue involves complete rem ect with a plastic and restoring the resulting defe ation. Endodontic treaatment tooth-colored restora o be require ed in cases in which thee ECR might also lesion has perforated the t root cana al. n discussing g treatmen nt options with When patients, itt is important to advise e patients th at the final decission on the e treatment (surgical rrepair_ endodonticc treatment versus extra action) can o only be objectivelyy made once e the full exttent of the E ECR is assessed, and this usu ually means surgical exp posure CR defect. However, H if a CBCT scaan has of the EC been take en, then the e treatmentt approach might confidentlyy be decided d on, rather than underrtaking exploratoryy surgical exxposure of the defect.

Internal and Externnal Cervical Ro oot Resorption ns

Case for External Resorptiv ve Defect In the co onventional pperiapical ra adiography, an a intternal resorptive defectt was deteccted on rig ght ma andibular central incisor (Fig. 2A). However a pin nk sp pot was prese ent on tooth and accuraccy of diagnossis wa as queried. After perfoorming a CBCT C scan, a de efinite extern nal resorptioon was dettected on th he sagittal plane located on the cervical region of th he too oth (Fig. 2B)). Treatmentt plan was to otally change ed. If diagnosis we ere performeed on basis of o a 2D imag ge, ed probably root canal obturaation would be performe ng ussing an injectable guttaa-percha sysstem diffusin ou ut from the resorptive areea to the cancellous bon ne. Vittality tests showed s thatt the tooth was vital an nd root canal tre eatment wass not necesssary. A small gin ngival flap was w elevated,, the inflame ed granulatio on tisssue was removed, thhe cavity was w debride ed, sh haped and obturated usiing glass-ion nomer ceme ent (G GC Fuji II, To okyo, Japan)) according to t the metho od of Heithersay (34). CBCT scanning ex xactly change ed the treatment modality.

pical radiograaphy in 2D sh hows a defec ct similar to tthe appearance of intern nal Figure 2. (A) Conventional periap ption on righ ht mandibula ar central inccisor; (B) CB BCT image on o the sagitta tal plane indiicates that th he root resorp defect is a an external cervical c resorption and th he treatment modality iss quite differrent from the e internal ro oot resorption. A gingival flap f is planne ed to elevatee to reach th he affected area. Surgicall approach was w mandato ory e. in this case

3 35

Internal and External Cervical Root Resorptions

Yiğit Özer

Discussion The use of CBCT can be invaluable in the decision-making process. The scanned data provide the clinician with a 3-dimensional appreciation of the tooth, the resorption lesion, and the adjacent anatomy. The true nature of the lesion might be assessed, including root perforations and whether the lesion is amendable to treatment. In the same study (39), the authors concluded that there was a significantly higher prevalence in the choice of the correct treatment option when CBCT was used compared with the use of intraoral radiographs for diagnosing resorptive lesions. Kim et al (40) analyzed a case of multiple extracanal invasive resorptions by using CT and a rapid prototyping tooth model. The use of CT was very helpful in diagnosing the exact size and location of resorption. In the serial cross-sectional views, the size and the location of resorption were clearly determined. The 3-dimensional reconstruction and the fabrication of a rapid prototyping tooth model provided a more accurate image of the resorption area. In simulated external RR, Silveira et al (41) evaluated the diagnostic performance of a CT scan table. External RR defects of different sizes and in different locations were simulated in 59 human mandibular incisors. Cavities simulating RR defects of 0.6, 1.2, or 1.8 mm in diameter and 0.3, 0.6, or 0.9 mm in depth (small, medium, and large defects) were drilled in the cervical, middle, and apical thirds of buccal surfaces. Axial CT was used to obtain cross-sectional images of the teeth, and 177 root thirds were assessed by a blinded observer. CT showed good diagnostic performance, high sensitivity, and excellent specificity in the detection of simulated external resorptions. The greatest difficulty was found in the detection of small resorptions located in the apical third of tooth roots. CBCT scans were effective to identify the presence, type, and severity of RR (42,43).

Conclusions Cone beam computed tomography appears to be a promising diagnostic tool for confirming the presence, appreciating the true nature, and managing the internal and external root resorptions. In addition to the 2-D slices, 3-D reconstruction enables further assessment of the area of interest which enables the right treatment modality for the real pathology.

References 1.

6. 7. 8.

10.

11. 12.

13. 14.

15. 16.

Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG. Endodontic applications of conebeam volumetric tomography. J Endod 2007;33:1121–32. Scarfe WC, Farman AG, Sukovic P. Clinical applications of cone-beam computed tomography in dental practice. J Can Dent Assoc 2006;72:75– 80. Yajima A, Otonari-Yamamoto M, Sano T, et al. Cone-beam CT (CB Throne) applied to dentomaxillofacial region. Bull Tokyo Dent Coll 2006;47:133– 41. Ziegler CM, Woertche R, Brief J, Hassfeld S. Clinical indications for digital volume tomography in oral and maxillofacial surgery. Dentomaxillofac Radiol 2002;31:126-30. Lofthag-Hansen S, Huumonen S, Grondahl K, Grondahl HG. Limited cone-beam CT and intraoral radiography for the diagnosis of periapical pathology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:114 –9. Gartner AH, Mack T, Somerlott RG, Walsh LC. Differential diagnosis of internal and external root resorption. J Endod 1976;2:329 –34. Gulabivala K, Searson LJ. Clinical diagnosis of internal resorption: an exception to the rule. Int Endod J 1995;28:255– 60. Patel S, Dawood A, Whaites E, Pitt Ford T. The potential applications of cone beam computed tomography in the management of endodontic problems. Int Endod J 2007;40:818–30. Estrela C, Bueno MR, Leles CR, Azevedo B, Azevedo JR. Accuracy of cone beam computed tomography and panoramic radiography for the detection of apical periodontitis. J Endod 2008;34:273–9. Patel S, Dawood A, Whaites E, Pitt Ford T. New dimensions in endodontic imaging: part 1— conventional and alternative radiographic systems. Int Endod J 2009;42:447–62. Gröndahl H-G, Hummonen S. Radiographic manifestations of periapical inflammatory lesions. Endod Topics 2004;8:55–67. Huumonen S, Kvist T, Grondahl K, Molander A. Diagnostic value of computed tomography in retreatment of root fillings in maxillary molars. Int Endod J 2006;39:827–33. Bell T. The anatomy, physiology, and disease of the teeth. Philadelphia, PA: Carey and Lee Publishing; 1830. 171–2. Levin L, Trope M. Root resorption. In: Hargreaves KM, Goodis HE, eds. Seltzer and Bender’s dental pulp. Chicago, IL: Quintessence Publishing Co Inc; 2002:425–48. Haapasalo M, Endal U. Internal inflammatory root resorption: the unknown resorption of the tooth. Endod Topics 2006;14:60–79. Patel S, Kanagasingham S, Pitt Ford T. External cervical resorption: a review. J Endod 2009;35:616–25.

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Yiğit Özer 17. Frank AL. External-internal progressive resorption and its nonsurgical correction. J Endod 1981;7:473–6. 18. European Society of Endodontology. Quality guidelines for endodontic treatment: consensus report of the European Society of Endodontology. Int Endod J 2006;39:921–30. 19. Gençoğlu N, Yıldırım T, Garip Y, Karagenç B, Yılmaz H. Effectiveness of different gutta-percha techniques when filling experimental internal resorptive cavities. Int Endod J 2008;41:836–42. 20. Goldman F, Massone EJ, Esmoris M, Alfie D. Comparison of different techniques for obturating experimental internal resorptive cavities. Endod Dent Traumatol 2000;16:116–21. 21. Stamos DE, Stamos DG. A new treatment modality for internal resorption. J Endod 1986;12:315–9. 22. Wilson PR, Barnes IE. Treatment of internal root resorption with thermoplasticized gutta-percha: a case report. Int Endod J 1987;20:94–7. 23. Torabinejad M, Hong CU, Pitt Ford TR, Kariyawasam SP. Tissue reaction to implanted Super EBA and Mineral Trioxide Aggregate in the mandible of guinea pigs: a preliminary. J Endod 1995;21:569–71. 24. Regan JD, Gutmann JL, Witherspoon DE. Comparison of Diaket and MTA when used as root-end filling materials to support regeneration of the periradicular tissues. Int Endod J 2002;35:840–7. 25. Main C, Mirzayan N, Shabahang S, Torabinejad M. Repair of root perforations using mineral trioxide aggregate: a long term study. J Endod 2004;30:80–3. 26. Jacobovitz M, Vianna ME, Pandolfelli VC, Oliveira IR, Rossetto HL, Gomes BP. Root canal filling with cements based on mineral aggregates: an in vitro analysis of bacterial microleakage. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;108:140–4. 27. Hsien H-C, Cheng Y-A, Lee Y-L, Lan W-H, Lin CP. Repair of perforating internal resorption with mineral trioxide aggregate: a case report. J Endod 2003;29:538–9. 28. Jacobowitz M, de Lima RK. Treatment of inflammatory internal root resorption with mineral trioxide aggregate: a case report. Int Endod J 2008;41:905–12. 29. Frank AL, Weine FS. Nonsurgical therapy for the perforative defect of internal resorption. J Am Dent Assoc 1973;87:863– 8. 30. Patel S, Pitt Ford T. Is the resorption external or internal? Dental Update 2007;34:218–29. 31. Heithersay GS. Clinical, radiologic and histopathologic features of invasive cervical resorption. Quint Int 1999;30:27–37. 32. Heithersay GS. Invasive cervical resorption: an analysis of potential predisposing factors. Quint Int 1999;30:83–95. 33. Heithersay GS. Invasive cervical resorption following trauma. Aust Endod J 1999;25:79–85. 34. Heithersay GS. Treatment of invasive cervical resorption: an analysis of results using topical

Internal and External Cervical Root Resorptions

35. 36. 37. 38. 39. 40.

41. 42. 43.

application of trichloroacetic acid, curettage and restoration. Quint Int 1999;30:96–110. Fish EW. Benign neoplasia of tooth and bone. Proc R Soc Med 1941;34:427–32. Southam JC. Clinical and histological aspects of peripheral cervical resorption. J Periodontol 1967;38:534–8. Frank AL, Blakland LK. Non endodontic therapy for supra osseous extracanal invasive resorption. J Endod 1987;13:348–55. Gold SI, Hasselgren G. Peripheral inflammatory root resorption: a review of the literature with case reports. J Clin Periodontol 1992;19:523–34. Trope M. Root resorption due to dental trauma. Endod Topics 2002;1:79–100. Bergmans L, Van Cleynenbreugel J, Verbeken E et al. Cervical external root resorption in vital teeth: X-ray microfocus—tomographical and histopathological study. J Clin Periodontol 2002;29:580–5. Frank AL, Torabinejad M. Diagnosis and treatment of extracanal invasive resorption. J Endod 1998;7:500–4. Rankow HJ, Krasner PR. Endodontic applications of guided tissue regeneration in.endodontic surgery. Oral Health 1996;86:33–5. Patel S, Dawood A, Wilson R, Horner K, Mannocci F. The detection and management of root resorption lesions using intraoral radiography and conebeam computed tomography: an in vivo investigation. Int Endod 2009;42: 831–8.

Case Report

Int Dent Res 2011;1:38-41

A Fibre-Reinforced Fixed Partial Denture on a Hemisectioned Tooth: A Case Report Süleyman AGÜLOĞLU1, Emrah AYNA2, Eylem ÖZDEMİR1 1 2

Assistant Professor, Dicle University, Faculty of Dentistry, Department of Prosthetic Dentistry, Diyarbakır, TURKEY Associate Professor, Dicle University, Faculty of Dentistry, Department of Prosthetic Dentistry, Diyarbakır, TURKEY

Abstract Key Words Fibre-reinforced, adhesive bridge, hemisection Correspondence: Eylem ÖZDEMİR Dicle University, Faculty of Dentistry, Department of Prosthetic Dentistry, 21280, Diyarbakir, TURKEY. e-mail: dteylem@yahoo.com

In modern dentistry, fibre-reinforced fixed dental prostheses are considered a useful alternative to classical metal-ceramic restorations. This method allows a conservative approach for replacing missing teeth that overcomes some of the drawbacks of conventional prostheses. Our patient required extraction of tooth #46 because of an apical lesion of the mesial root, and underwent extraction by hemisection. After healing, using the superior properties of the combined fibre/composite, an adhesive bridge restoration was applied with support from the distal root of tooth #46 and teeth #45 and #47. (Int Dent Res 2011;1:38-41)

Introduction For many years, the only prosthetic application used to deal with cases with a single missing tooth was a fixed partial prosthesis. However, the preparation of the two teeth required for correction of a single tooth deficiency causes unnecessary tissue loss. Subsequently, implant-supported fixed prostheses have been developed as an effective solution for this situation. Inevitably, implants cannot be used in some patients because surgical intervention is contraindicated due to systemic disease or the high cost of the operation. Adhesive bridges are a good alternative, as they are less expensive than implants, they do not require surgical intervention and the loss of material from the supporting tooth is small compared to conventional bridges. With the development of fibrestrengthened composites, alternative restorations have become very popular (1-4). Fibre-reinforced composites have good mechanical properties and their endurance/weight ratios are high compared to metal alloys. Fibrereinforced composites have several advantages: they are translucent, unlike metals; non-corrosive, easy to repair, have good adhesive properties and it 38

is easy to prepare the mouth to receive them. In dentistry, glass, polyethylene and carbon fibres are mainly used as the strengthening materials for composites. Saturated fibres are used as the substructure material for a fixed partial prosthesis, whereas ceramic-reinforced restorative composites are used as the superstructure material (1-7)

Case Report A 31-year-old male patient visited our faculty complaining of problems with tooth #46, and an apical lesion of the mesial root was detected. Based on the results of radiography and intraoral inspections, the distal root of the tooth was deemed usable (Fig. 1A). After endodontic therapy, the tooth was hemisectioned and the mesial root was separated (Fig. 1B and Fig. 1C). Following the healing period, a mandibular impression was obtained and tooth wax was used to plan the bodygum relationship for model preparation (Fig. 1D and Fig. 1E).

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e radiographic image of tthe tooth #4 46; (B) Sepa arating the rooots of the to ooth #46; (C C) Figurre 1. (A)The The remaiining distal root; r (D) Th he buccal deesign of the tooth wax that was ussed to plan the body-gu um relationship for model preparation;; (E) The lin ngual design of the tooth h wax that w was used to plan p the bod dygum relatio onship for model m prepara ation; (F) Th he obtained impression of the tooth w wax.

g a piece of silicon, a sub-body imprression Using of the waxx tooth was obtained o (Fig g. 1F and Fig g. 2A). This impre ession was then placed d in the too othless region and d the composites were built on top o of it as the next sstep in proce essing the mouth. On thee next visit, a rub bber dam wa as placed in the mouth, and a first glass fibre post (Snowpost; Kuraray Meedical, Japan) wa as placed in the remain ning distal ro oot of tooth #46 6 (Fig. 2B) for strength h, and the crown length wa as increased. Cavities were w prepareed for placing po olyethylene fibre in teeth #45 and #4 47 and e etched witth 35% phossphoric acid for 15 these were seconds affter the polye ethylene fibrre cord (Consstruct, Kerr Corp., Switzerland d) was cut to twice the length gion, and the e cavity wass then of the resstoration reg washed an nd dried. Cle earfil SE Bon nd primer (Ku uraray Medical) w was applied for 20 s, an nd the cavitty was dried with slow air flo ow. To give the t ideal shaape to gum, silicon previously prepared p on top of the body-g the mode el was place ed over the e crest and d then Clearfil SE E Bond (Kuraray Medica al) was appl ied to the cavitie es. In addition, a polyetthylene fibree cord previously cut to the appropriate e size was w wetted ding agent and a placed as a a doublee layer with bond between th he cavities in n teeth #45 and a #47 succh that

it also adhered d to the distaal root of #4 46 (Fig. 2C). It wa as then poly ymerised witth light for 10 s. Clearrfil Ph hoto Posterio or (Kuraray Medical) co omposite was pla aced on top of the silicoon model fo ormer to covver the entire fibre and tootth #46 wass shaped an nd olymerised with w light. Thee silicon mod del former was po cu ut and remo oved from the mouth. Finally, th he occclusion of th he new toothh was shaped d and polishe ed (Fig. 2D and Fig. 2E).

Discu ussion In this sttudy, a glasss fibre postt was used to T an nd strrengthen and lengthen the root. Torbjorner Fra ansson8 rep ported that crown fabrication usin ng prefabricated posts and reesin compossite is a viab ble ed tecchnique forr weakenedd, endodonttically treate roots, especially for the a nterior teeth h of teenage ers ndicated. Peroz in whom a posst-core crownn is contrain ation results in et al.9 reported that adhessive cementa wer microlea akage and hiigher retentiion and that it low is preferred for metal postss.

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Fiibre-reinforced d Fixed Partiall Denture

Agü üloğlu et al.

Figure 2 2. (A) The silicon model former; (B)) Glass fibre e post was placed in the rremaining diistal root of to ooth #46; (C C) The silicon model form mer at work;; (D) The prrepared tooth h; (E) The laast occlusion n and bodygum relationsship design.

ade with fib brePreviouslly, adhesive bridges ma re einforced co omposites were w conside ered temporaary re estorations. However, with w progress in mate rial sccience, these e restorations have been used for maany ye ears. Furthe ermore, these e teeth are not as hard as porcelain tee eth, which reduces r the wear on tthe opposite tootth. In addittion, they are transluceent, dhesive prop perties, are easy e to prepaare have good ad nd they are resistant to corrosion. T The and repair, an c in n resin-bond ded use of fibre--reinforced composite xed partial dentures (F FPDs) has been suggestted fix because the composite lu uting agent adheres bettter o the framew work, the ressults are goo od aestheticaally to and the fra amework material m hass physiologiical sttiffness. The rep ported 5-yea ar survival rate of meetal alloy/resin-bo onded FPDs with w one po ontic is 61%.. If he rebonded d FPDs in thiis study werre reconsiderred th in n the statisttical analysiss, the surviv val rate wo uld in ncrease to 7 76% after 5 years, and this has beeen re eferred to ass the functio onal survival rate (5). So me sttudies have e indicated that resin-bonded FP PDs placed in the e mandible have lower survival ra tes

40 4

d in the maxxilla, while otther studies than those placed ated no diffe erences in suurvival of FP PDs located indica in the mandible and maxillaa.2-3-4-5 Altieri et al. w fibre1applied fixed adhesive p rostheses with reinfo orced comp posite in 14 patientts without prepa aring the tooth and achieeved 50% su uccess after a one e-year period. In I summary, although tthe region restored r in our patient p is a re egion used fo for chewing, we believe that the restorattion will surrvive for a long time use of the su upport from the distal ro oot of tooth becau #46, together witth the suppoort from teetth #45 and #47.

Refere ences 1--

2--

Altieri JV, Burstone CJ,, Goldberg AJ, Patel AP. er-reinforced Longitudinal clinical evaaluation of fibe p study. J composite fixed partial dentures: a pilot Prosthet Dent. 1994 Jann;71(1):16-6 Mudassir, Y.E. Y Aboush, M. Hosein, T. Hosein and I. Padiharr. Long-term clinical perfformance of

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78-

10-

11-

12-

1314-

15-

1617-

18-

resin-bonded fixed partial dentures placed in a developing country. J Prosthodont 1995; 4: 233– 3 P. Rammelsberg, P. Pospiech and W. Gernet. Clinical factors affecting adhesive fixed partial dentures: a 6-year study. J Prosthet Dent. 1993; 70: 300–7 M. Behr, A. Leibrock, W. Stich, P. Rammelsberg, M. Rosentritt and G. Handel. Adhesive-fixed partial dentures in anterior and posterior areas. Results of an on-going prospective study begun in 1985. Clin Oral Investig. 1998; 2: 31–4 Vallittu PK. Survival rates of resin-bonded, glass fiber-reinforced composite fixed partial dentures with a mean follow-up of 42 months: a pilot study. J Prosthet Dent. 2004 Mar; 91(3): 241-6. N.H. Creugers, P.A. Snoek, M.A. van't Hof and A.F. Kayser. Clinical performance of resin-bonded bridges: a 5-year prospective study: II. The influence of patient-dependent variables. J Oral Rehabil 1989; 16: 521-6 H.K. Chang, O. Zidan, I.K. Lee and O. GomezMarin. Resin-bonded fixed partial dentures: a recall study. J Prosthet Dent 1991; 65:778–3 Torbjorner A, Fransson B. A literature review on the prosthetic treatment of structurally compromised teeth. Int J Prosthodont 2004; 17:369-7 Peroz I, Blankenstein F, Lange KP, Naumann M. Restoring endodontically treated teeth with posts and cores: a review. Quintessence Int 2005; 36:737-9 R.J. De Kanter, N.H. Creugers, C.W. Verzijden and M.A. van't Hof. A five-year multi-practice clinical study on posterior resin-bonded bridges. J Dent Res 1998; 77: 609–5 N.H. Creugers, R.J. De Kanter, C.W. Verzijden and M.A. van't Hof. Risk factors and multiple failures in posterior resin-bonded bridges in a 5year multi-practice clinical trial. J Dent 1998; 26: 397–5 N.H. Creugers, A.F. Käyser and M.A. van't Hof. A seven-and-a-half-year survival study of resinbonded bridges. J Dent Res 1992; 71: 1822– 1825 B.J. Crispin. A longitudinal clinical study of bonded fixed partial dentures. The first 5 years. J Prosthet Dent 1991; 66: 336–6 M. Kellett, C.W. Verzijden, G.A. Smith and N.H. Creugers. A multicentered clinical study on posterior resin-bonded bridges: the Manchester trial. J Dent 1994; 22: 208–4 C.W. Verzijden, N.H. Creugers and J. Mulder. A multi-practice clinical study on posterior resinbonded bridges: a 2.5-year interim report. J Dent Res 1994; 73: 529–6 K.W. Boening. Clinical performance of resinbonded fixed partial dentures. J Prosthet Dent 1996; 76: 39–5 Moosavi H, Maleknejad F, Kimyai S. Fracture resistance of endodontically-treated teeth restored using three root-reinforcement methods. J Contemp Dent Pract. 2008 Jan 1;9(1):30-7 Garoushi SK, Vallittu PK, Lassila LV. Short glass fiber-reinforced composite with a semi-

interpenetrating polymer network matrix for temporary crowns and bridges. J Contemp Dent Pract. 2008 Jan 1;9(1):14-21