Evaluation of the effectiveness of different rotary file systems in removing root canal filling materials from teeth treated with different root canal sealers

Objective: This study aimed to compare the amount of remaining root canal sealer following retreatment in teeth previously obturated using either an epoxy resin-based or a calcium silicate-based sealer. In addition, the effectiveness of different rotary file systems in removing root canal filling materials during retreatment procedures was evaluated. Materials and Methods: A total of 40 extracted mandibular molars were used. All samples were instrumented using the ProTaper Gold system. In the first group, root canal obturation was performed using an epoxy resin-based sealer (AH Plus Jet) and gutta-percha, while in the second group, a calcium silicate-based sealer (AH Plus Bioceramic) and gutta-percha were used. During retreatment, ProTaper Universal Retreatment files were used in Group A, and XP-Endo Rise Retreatment files in Group B. The volume of residual filling material was quantified using high-resolution micro-computed tomography (micro-CT). Statistical analysis was performed using independent samples t-test, one-way ANOVA, and Bonferroni post hoc test. Results: The group obturated with AH Plus Jet exhibited significantly more residual filling material compared to the AH Plus Bioceramic group (p = 0.04). XP-Endo Rise Retreatment files were significantly more effective in removing root canal filling material than the ProTaper Universal Retreatment files (p = 0.01). Conclusion: Both the type of root canal sealer and the rotary retreatment file system affected the removal efficiency of filling materials. However, none of the tested systems were able to completely remove the root canal filling.