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.

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: Blood contamination of the canal during preparation can be a major problem in endodontics; this may result in apical micro leakage. The aim of this in vitro study was to evaluate the effect of blood on apical micro leakage of a resin-based root canal SEALER (AH26) and a polymer-based root canal SEALER (EPIPHANY).MATERIALS & METHODS: In this experimental study, 50 decoronated central incisors and canine teeth were prepared by Ra Ce rotary system and randomly divided into 4 groups (n=10). Groups A1 and A2 were obturated by EPIPHANY/Resilon and AH26/Gutta-percha, respectively. The obturations were performed with a single cone technique after drying root canals. In B1 and B2 groups, the test groups, 0.02cc citrated human blood was injected into dried root canals and they were obturated in the same manner. Ten specimens were served as positive and negative controls (n=5).The apical leakage was measured by means of a computerized fluid filtration method after 1 day and 3 weeks. The data was analyzed by One-Sample K olmogorov-Smirnov, Independent Sample t-test and univariate analysis. Statistical significances were preset at a=0.05.RESULTS: There was no significant difference in apical micro leakage of the two SEALERs after 1 day and 3 weeks in dry and blood environment (P>0.05). SEALER and environment had no interaction (P>0.05).CONCLUSION: Blood contamination has no significant effect on the apical micro leakage of EPIPHANY and AH26.

Introduction: Vertical root fracture inevitably leads to tooth extraction. Thus, root filling with obturating materials and SEALERs that can reinforce the tooth would be an ideal way to reduce fracture in root treated teeth. This study aimed to assess the fracture resistance of roots following the application of different SEALERs including EPIPHANY, iRoot SEALER and AH-plus. Methods and Materials: Fifty extracted human single-canal premolars without caries, curvature or cracks were used in this study. Tooth crowns were cut to yield 13-mmlong roots. Five roots were put in the negative control group and were left unprepared. Forty-five canals were prepared using ProTaper rotary files up to F3 and were then randomly divided into three groups based on the SEALER type (n=15). The root canals were filled using cold lateral condensation technique with gutta-percha and AH-Plus SEALER, gutta-percha and iRoot SEALER and Resilon and EPIPHANY SEALER, in groups one to three, respectively. The roots were then mounted in acrylic molds for fracture resistance testing and subjected to compressive load at a crosshead speed of 1mm/min until fracture. Data were analyzed using the one-way ANOVA. Results: The mean fracture resistance was 673. 38± 170. 42 N in AH-Plus, 562. 00± 184. 68 N in iRoot, 708. 03± 228. 05 N in Resilon and 592. 59± 117. 29 N in the control group. No statistically significant difference was found between the experimental groups and the negative control group (P=0. 26). Conclusion: Application of AH-Plus, bioceramic and Resilon SEALERs did not change the fracture resistance of roots compared to that of unprepared root canals.