Iranian Endodontic Journal

Abstract

Introduction: Root canal retreatment is challenged by the strong adhesion of sealers to dentin. AH-Plus Bioceramic, an epoxy resin-based sealer containing calcium silicate components, could present particular difficulty during removal. This study evaluated whether 5% formic acid with passive ultrasonic activation (PUI) is as effective as 10% formic acid and 2% sodium hypochlorite (NaOCl) in the removal of residual filling material of teeth obturated with AH-Plus Bioceramic sealer. Materials and Methods: Thirty-three lower premolar roots were obturated with AH-Plus Bioceramic sealer using a single-cone technique. After instrumentation with the Reciproc R40 file, the roots were randomly assigned to three groups of final irrigation: 5% formic acid, 10% formic acid, and 2% NaOCl, all combined with PUI. The volume of filling material was measured using cone-beam computed tomography (CBCT) analysis at three stages: after obturation, after instrumentation for retreatment, and after final irrigation with formic acid or NaOCl combined with PUI. Statistical analysis included Friedman and Wilcoxon tests for intragroup comparisons and the Kruskal–Wallis test with Dunn’s post hoc test for intergroup comparisons. Results: All irrigants combined with PUI reduced the filling material volume with no significant differences among them (P>0.05). Conclusion: Ultrasonically activated 5%, 10% formic acid, and 2% NaOCl showed similar removal of residual filling material containing AH-Plus Bioceramic sealer.