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2014; Vol.3,No.1 January -March
ISSN 2319 – 4154

Original Articles

Comparative evaluation of the apical seal of resilon™ with sealer, guttapercha with resin sealer and guttapercha with zinc oxide eugenol sealer in permanent single rooted teeth an in vitro study

Jyoti Sumi Issac1, N. Venugopal Reddy, V. Arun Prasad Rao, Krishna Kumar
1Department of Pediatric Dentistry, PMS College of Dental Science and Research, Venkode PO., Trivandrum, Kerala - 695028 and Department of Pediatric Dentistry,
Rajah Muthaiah Dental College & Hospital, Chidambaram, Tamil Nadu
Correspondence to: drjissac18@gmail.com

  • Abstract

    Objective: The era of endodontics has taken a new dimension with the advent of a synthetic, thermoplastic resin filling material, named Resilon. Our in vitro study tested the efficacy of this new obturating system, versus the age-old material Guttapercha.

    Materials & Methods: Forty five central incisor teeth, extracted due to periodontal reasons, were assigned to two experimental (Resilon and AH 26) and one control group. They were obturated by lateral condensation method, immersed in 2% methylene blue solution, sectioned longitudinally and examined under stereomicroscope. Dye penetration was recorded as an indicator of microleakage. Analysis of variance (One Way ANOVA) and post hoc multiple comparisons were used for statistical analyses.

    Results: Analysis of variance (One Way ANOVA) showed highly significant (P<0.001) difference among the groups tested. Post hoc multiple comparisons revealed the difference between groups, of which dye penetration in Resilon and AH 26 was significantly different from control and between themselves.

    Conclusion : Resilon has better sealing ability when compared to the other two filling materials .

    Introduction

    The primary objectives of operative endodontics are total debridement of the pulpal space, development of a fluid–tight seal at the apical foramen and total obturation of the root canal.1 Guttapercha has been accepted for years due to its biocompatibility, dimension stability, compactibility, thermoplasticity and ease of removal. However, there is a major flaw with filling root canals with Guttapercha and sealer in that it is unable to create a dependable seal of the root canal system.2 A wide variety of root canal sealers are available and these include cements based on organic resins, calcium hydroxide and Zinc oxide Eugenol.3 In an effort to improve the obturation of the root canal system new techniques and materials have been developed. The most promising new material which could be considered as a replacement for Guttapercha is ResilonTM (Pentron Clinical Technologies, Wallingford, CT).4 ResilonTM is a synthetic, thermoplastic resin filling material that is believed to overcome the limitations and problems associated with Guttapercha.5 The system consists of ResilonTM core material, EpiphanyTM primer and EpiphanyTM seale. There have been only a few studies conducted to test the microleakage of ResilonTM with other standard obturating materials and sealers. Hence this in vitro study was undertaken to evaluate the sealing ability of this new root canal filling material along with its recommended sealer and also to compare the sealing ability of this new material with routinely used root canal obturating materials (Guttapercha with AH 26 epoxy resin sealer and Guttapercha with Zinc Oxide Eugenol sealer).

    Materials and Methods

    A total of forty five permanent single rooted central incisor teeth extracted due to periodontal reasons, were collected and stored in 0.9% normal physiological sodium chloride solution.6 Teeth which were not subjected to prior root canal treatment and teeth having one single canal and one main apical foramen were included in the study.7 Teeth with calcified canals, extra canals, extremely curved canals, open apices, cracks, or external or internal resorption were eliminated. All calculus and periodontal remnants were carefully removed with ultrasonic scaling to allow better adherence of the nail polish surface sealant. The teeth were placed in three clean containers marked [a] ResilonTM [b] AH 26 [c] Control groups respectively and filled with physiologic saline solution and stored in the refrigerator to inhibit bacterial growth. The specimens were divided into three and all the three groups had 15 teeth each.

  • The teeth were distributed evenly with regard to length and prepared in a standardized manner. First group was formed with ResilonTM with EpiphanyTM sealer. Second Group, Guttapercha with a resin based sealer and third group kept as control was formed of Guttapercha with Zinc Oxide Eugenol sealer. All of these specimens were totally covered with three coatings of nail varnish (as surface sealant), including the apical and coronal ends. Access opening was done on each tooth and the canal working lengths were visually established by placing a size 20 K-file into each canal until the tip of the files were visible at the tip of the apical foramen. The working length was established 1 mm short of the apex. Canal systems were instrumented to the working length with a size 40 K-file using a Step back preparation technique. Apical patency was maintained throughout the procedure by passing the tip of a size 20 K-file through the foramen and to provide a standardized preparation. The root canals were irrigated with 2ml of 5.25% NaOCl (Sodium hypochlorite) after the use of each file throughout the preparation. Smear layer was removed with 2 ml of 17% EDTA; finally, the canals were flushed with 2 ml saline solution and then dried with paper points. The obturation technique used was the lateral cold condensation technique, for all the groups.

    In the ResilonTM group, after drying the canals with paper points, self etch primer was placed into the root canal system to the working length with applicator tips. Dry paper points were then used to wick out the excess primer from the canal, according to the manufacturer’s instructions. Next the dual syringe (containing the sealer) with the auto mixing tip attached was used to express the sealer onto a mixing pad. The sealer was then placed into the root canal system by generously coating the master cone. The canals were then obturated. ResilonTM was cured immediately at the coronal end with a curing light for 40 seconds. According to the manufacturer’s instructions, light source was held 1-2 mm from the surface for 40 sec to obtain polymerization. Depth of curing was 2.5 to 3 mm per 20 seconds. The rest of the material is claimed to self cure within the next 45 minutes.7 Upon completion of obturation, all samples were again stored in their respective containers, filled with physiological saline solution at 37°C for 48 hours. Then they were taken out from the containers and the entire tooth surfaces were covered with 3 layers of nail varnish, allowing each coat to dry between applications except for the apical 3 mm.8 Post operative radiographs were exposed to evaluate the quality and density of the root canal obturation.7 All the specimens were placed in 2% methylene blue dye solution for 24 hours. They were then removed from the dye and rinsed with tap water, allowed to dry for 24 hours at 37°C before meticulously removing the nail varnish with a scalpel blade. Coronal tooth structure was removed with a separating disc perpendicular to the long axis of the tooth. Then they were sectioned longitudinally using water-cooled diamond discs in a bucco-lingual direction.9 Apical leakage was determined by using the dye penetration method.10,11 Each section was examined using a Stereomicroscope {STEMI 2000-C, Carl Zeiss, Germany} with microscope camera {MC 80, Carl Zeiss, Germany} at 40X magnification to assess the linear breakthrough of the dye using the standard measurements of a Stereomicroscope and evaluated by a single operator via pictures. After micro leakage examination, the results of the study were noted and subjected to statistical analysis.

    Statistical analysis

    Data were analyzed using computer software, Statistical Package for Social Sciences (SPSS) version 10. Analysis of variance (One Way ANOVA) was performed as parametric test to compare different groups. To elucidate multivariate comparisons, Duncan’s Multiple Range Test was performed as post hoc analysis along with ANOVA. For all statistical evaluations, a two-tailed probability of value, < 0.05 was considered significant.

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