Comparative Evaluation of Efficacy of Different Retreatment Systems in Removal of Root Canal Filling Materials – An in Vitro CBCT Study

AbstractBackground: Effective removal of existing root canal filling materials is essential for successful nonsurgical endodontic retreatment. However, complete elimination of obturating materials remains a clinical challenge irrespective of the instrumentation system used.Aim: To comparatively evaluate the efficacy of H-files, HyFlex Remover, and Endostar RE Endo systems in the removal of root canal filling materials using cone-beam computed tomography (CBCT).Materials and Methods: Thirty extracted human mandibular premolars were instrumented, obturated, and randomly allocated intothree groups (n=10 each): GroupI – H-files, GroupII – HyFlex Remover, Group III – Endostar RE Endo. Retreatment was performed using the respective systems, and residual filling material was quantified using CBCT analysis.Results: HyFlex Remover demonstrated the least residual filling material (1.68%), followed by Endostar RE Endo (2.94%), while H-files showed the highest residual material (4.57%). Statistically significant differences were observed among the groups, with rotary systems performing better than manual instrumentation.Conclusion: Within the limitations of this study, HyFlex Remover was the most efficient system for removal of root canal filling materials, followed by Endostar RE Endo and H-files.