Retreatability of root canals filled with Gutta percha and a novel bioceramic sealer: A scanning electron microscopy study.

Aim: This study aimed to evaluate the residual filling material and the reestablishment of working length (WL) and apical patency after retreatment of BioRoot™ RCS, versus TotalFill® BC Sealer, and AH26, used in a single cone obturation technique.

Materials and Methods: Sixty single-rooted permanent canines were instrumented up to size 40/.04 (Sendoline, Täby, Sweden). The samples were filled with GP/AH26 (Group 1), GP/TotalFill BC Sealer (Group 2), and GP/BioRoot RCS (Group 3). Eight teeth were used in the positive and negative control groups. Canals were retreated using the Protaper Universal retreatment files (Dentsply Maillefer, Ballaigues, Switzerland) and further instrumented up to size 50/.04 (Sendoline, Täby, Sweden). The ability to reestablish WL and apical patency was recorded. Furthermore, the samples were observed under a scanning electron microscope, in order to evaluate the residual filling material. Data were analyzed statistically with the Fisher's exact and the Kruskal-Wallis tests ( P < 0.05).

Results: There was no statistically significant difference in the WL and patency recovery among the groups. Neither the intragroup comparison among canal thirds nor the intergroup comparison in each canal third or in total canal area revealed any significant differences in the percentage of the remaining filling material after retreatment.

Conclusion: Residual material debris was observed in all samples regardless of the sealer used. All the sealers were removed to a similar extent. The WL and patency were reestablished sufficiently in all groups.