Comparative evaluation of the efficacy of different automated instruments for the removal of bioceramic sealer in retreatment cases: An In Vitro Scanning Electron Microscopic study.

Introduction: In endodontic retreatment, complete removal of bioceramic sealers is important for ensuring the success of the procedure and preventing future complications. This study aims to evaluate the efficacy of two automated retreatment instruments for removing bioceramic sealers and assess residual sealer on canal walls using Scanning Electron Microscopy (SEM). Materials and Methods: Twenty extracted, single-canal, lower premolars were used. After obturation with bioceramic sealers, samples were divided into two groups of ten each: Group 1 (G1): Protaper Universal Retreatment file system (Dentsply Mallefer, Switzerland); Group 2 (G2): Hyflex Coltene Remover (Coltene/ Whaledent, Switzerland). Canals retreated using the Protaper Universal retreatment files in Group 1 and Hyflex Coltene Retreatment files in Group 2 using standard irrigation protocol. Scanning electron microscopy (SEM) was used to evaluate the remaining filling materials. The obtained data will be put on statistical analysis by SPPS software. Results: No retreatment system was able to remove completely the bioceramic sealer from the root canal at the middle and apical thirds. However, Hyflex Coltene Remover is significantly able to remove bioceramic sealer in comparison to the Protaper Universal Retreatment file system (p < 0.05). Conclusion: Residual material debris was observed in all samples regardless of the retreatment instruments used. Hyflex Coltene Remover files emerged as a more effective choice for sealer removal in retreatment cases.