Objectives: To eliminate microorganisms that are responsible for pulpal and periapical infections and to prevent reinfection of the root canal system an effective chemo mechanical preparation by irrigants with sustained antimicrobial activity is beneficial. Hereby, we evaluated the residual antibacterial activity of MTAD after canal obturation at different time intervals.Materials and Methods: A total of 120 human single-canalled anterior teeth were selected. The root canals were instrumented to a standardized apical size. Among all, 90 teeth received final irrigation with MTAD and were divided into three groups according to their obturation materials; i.e. gutta-percha/AH26, RESILON/RealSeal SE and positive con-trols. All these groups were divided into three 1-, 3- and 6-week time interval subgroups. Thirty teeth as negative control had no final irrigation with MTAD, but were obturated with gutta-percha/AH26 or RESILON/RealSealSE. Dentin powder was prepared after 1, 3 and 6 weeks. Dentin powder was exposed to Enterococcus faecalis for 24h and then cultured. Colony Forming Unit (CFU) was counted.Results: Residual antimicrobial activity of MTAD in the teeth obturated with gutta-percha/AH26 was significantly higher than the teeth obturated with RESILON/RealSeal SE (p<0.001). It also showed a time dependent decrease in MTAD antimicrobial activity for all groups. The highest antimicrobial activity of MTAD was found in the 1-week positive control and 1-week gutta-percha/AH26 specimens. The lowest antimicrobial activity of MTAD was found in 6-week RESILON/RealSeal SE samples and then the negative controls.Conclusion: MTAD had antimicrobial activity even at the sixth week, although it had a time-dependent decrease. RESILON/Epiphany SE significantly decreased antimicrobial activity of MTAD at all time points.

Introduction: Endodontic surgery is a valuable option for maintaining patient's natural dentition when previous orthograde endodontic treatments fail to succeed. Proper rootend preparation and placement of a retro-filling material are recommended for successful endodontic surgery. The objective of this experimental study was to compare sealing ability of RESILON/Epiphany system, as a potential root-end filling material, with ProRoot MTA using both dye and bacterial leakage models.Materials and Methods: Ninety two single-rooted extracted human teeth were decoronated and prepared endodontically. Specimens were randomly divided into four experimental groups (n=20) and four control groups (n=3). After removal of apical 3 mm and root-end cavity preparation, MTA, or RESILON were used to fill root end cavities. For bacterial leakage, specimens (20 for each experimental group, 3 negative, and 3 positive controls) were subjected to E. faecalis over a 70-day period. Methylene blue was used for dye leakage (the same in number as before). Using stereomicroscope (40× mag.) complete dye leakage was assessed after 72 h. Kaplan-Meier survival analysis was performed for bacterial leakage. The data was analyzed using t-test and Chi-square analysis (a=0.05).Results: All of the positive controls and none of negative controls revealed leakage.Result of log rank test showed no significant difference between MTA and RESILON in time of bacterial leakage at the end of the 70 days (P>0.05) There was also no statistical difference in complete dye leakage for both groups (P>0.05).Conclusion: Leakage occurred in both MTA and RESILON as root-end filling material but the difference was not statistically significant. RESILON might be noticed as a potential root-end filling material if good isolation is attainable.

Objective: Application of chemical solvents especially in problematic canals is usually a part of the retreatment process.This study was performed to compare the solubility of Gutta-Percha and RESILON in chloroform and to find the effect of sample thickness as well as the time of shaking on their solubility.Materials and Methods: Specific weight of RESILON and gutta-percha was placed in a sample tube and after adding 1.0 ml of chloroform at 37oC, the tubes were capped and shaked for 1, 3 and 5 minutes. The amount of non dissolved material was determined by reweighting of each sample and the percent of solubility was assessed according to the exact weight loss of the samples. The procedure was repeated three times for a given thickness and time of shaking. The difference in the solubility of Gutta-Percha and RESILON as well as the effect of sample thickness and time of shaking on solubility were assessed by repeated measurement ANOVA (p<0.05).Results: RESILON has significantly higher solubility than Gutta-Percha in chloroform (p<0.05). RESILON as well as Gutta-Percha Solubility are increased significantly over the time.The amount of solubility is not affected by sample thickness.Conclusion: Comparison of RESILON and Gutta-Percha solubility in chloroform shows that one of the advantages for RESILON could be the chance for using possible safer organic solvents during retreatment.

Statement of Problem: Gutta-percha presents no adhesion to the tooth structure and SEALERs. Ideally, it should be replaced by a material that offers better sealing in the entire length of the root canal.Purpose: The aim of this study was to compare the coronal microleakage of a root canal filled with different pairs of Gutta-percha (GP), RESILON, Epiphany and AH26.Materials and Method: For this study, 130 mandibular premolars were chosen. After decoronation and preparation of the root canals of the teeth, they were divided into four experimental groups with 30 teeth each and 2 control groups. Group one was obturated with GP and AH26 SEALER, group two with GP and Epiphany SEALER, group three with RESILON tips and Epiphany SEALER, and group four with RESILON tips and AH26 SEALER. All the groups were obturated, using cold lateral condensation. Micro-leakage was tested using a two-chamber bacterial method. The data were subjected to statistical analysis, using a Kaplan-Meier test.Results: The bacterial microleakage test showed no significant difference between groups (p =0.1718).Conclusion: It is concluded that, in vitro, the epiphany obturation system is as good as gutta-percha sealed with AH26 when compared over 90 days of saliva storage.

Introduction: The success of endodontic retreatment is related to the complete removal of the obturation material from the root canal system. The aim of this study was to evaluate the efficacy of Mtwo R and ProTaper retreatment files in removing the RESILON/Epiphany system with or without chloroform during retreatment.Materials and Methods: Sixty distal roots of first mandibular molars were prepared and laterally condensed with RESILON/Epiphany, then divided into four groups (15 each for retreatment): 1) Mtwo R/solvent; 2) Mtwo R; 3) ProTaper D/solvent; and 4) ProTaper D. The cleanliness of the canal walls was evaluated using radiography; a stereomicroscope and SEM. Data were subjected to ANOVA and Student’s t-test.Results: Neither rotary system performed better than the other when considering the whole root canal, with or without solvent. In the apical portion, ProTaper/solvent showed the best result (P<0.05).Conclusion: In RESILON/Epiphany retreatment cases, ProTaper/solvent was better in the apical portion; however when considering the whole canal, Mtwo R and the ProTaper D series had the same performance.

INTRODUCTION: The aim of this study was to evaluate the apical and coronal seal of endodontic filling promoted by the combined use of SEALER 26/gutta-percha, Endofill/gutta-percha and RESILON/ Epiphany.MATERIALS & METHODS: A total of 38 extracted human canine teeth were selected; 10 teeth for each test group and 4 for each control group. After conducting conventional endodontic treatment, the teeth were immersed in saline solution for thirty days, and subsequently sealed and stored in India ink for seven days. They were then cleaned and evaluated for infiltration by stereoscopic microscope. The data were statistically analyzed by ANOVA and Bonferroni tests.RESULTS: The results showed no significant differences between the three groups of filling materials used.CONCLUSION: Within the limitations of this in vitro study, no material showed superiority in their apical and coronal seal.

Introduction: Dentin removal during root canal instrumentation creates a weaker root structure and increases its potential to fracture. The aim of this in vitro experimental study was to compare fracture resistance of teeth filled with gutta-percha, and RESILON using two different techniques.Materials and Methods: This study was performed on 105 single-canal extracted maxillary incisors. Samples were divided into seven groups of 15 each. Three groups were prepared with K-files; three groups with Race rotary files and in one group no preparation was carried out. Of all samples prepared either manually or with rotary instruments, 15 teeth were obturated using gutta-percha and AH26 SEALER, 15 teeth were filled with RESILON and 15 teeth remained unfilled. Loading force to fracture was measured and ANOVA and Tukey tests were used for statistical analysis.Results: No statistically significant differences were observed between different preparation techniques. The intact roots showed significantly greater fracture resistance compared to both instrumented groups (P<0.01). RESILON Group showed significantly higher resistance than gutta-percha Group (P<0.01); however the difference between RESILON and intact teeth was not statistically significant.Conclusion: Accoding to the results of this in vitro study, root canal filling using RESILON may increase the fracture resistance of treated teeth.

Introduction: The purpose of this study was to evaluate the sealing ability of gray-colored mineral trioxide aggregate (GMTA), white-colored MTA (WMTA), and RESILON as root filling materials.Materials and Methods: Sixty-six human maxillary central incisors were used in the present study. In the group A, 20 teeth were filled with GMTA. In the group B, 20 teeth were filled with WMTA and in the group C, 20 teeth were filled with RESILON/Epiphany. Three teeth were used as positive (obturated using the single gutta-percha cone technique without SEALER) and three were used as negative (obturated with gutta-percha and AH-26 SEALER, coated with two layers of nail varnish) controls. A bacterial leakage model utilizing Enterococcus faecalis was used for evaluation. Leakage was noted when turbidity was observed.Results: Controls behaved as expected. In the group A (GMTA) three samples, in the group B (WMTA) four samples, and in the group C (RESILON/Epiphany), two samples were leaked. There was no statistically significant difference between GMTA and WMTA or GMTA and RESILON.Conclusion: In conclusion, sealing ability of GMTA and WMTA was similar to RESILON as orthograde root filling materials.