Comparison of Residual Bioceramic and Epoxy Resin Sealers Following Retreatment with Reciprocating File System in Oval Root Canals: A Micro-computed Tomography Study

Introduction: When endodontic treatment has failed, non surgical retreatment is often the first choice. This procedure includes removal of previous obturating material followed by chemomechanical preparation, disinfection and refilling of the root canals. However, residual sealer during retreatment remains a concern when such bioceramic sealers are utilised for obturation and this can affect the prognosis. Aim: To evaluate and compare the amount of residual filling material after retreatment in straight and oval root canals filled with iRoot SP and AH Plus sealer using V-Blue file system using Micro-Computed Tomography (micro-CT). Materials and Methods: This in-vitro study was conducted at Bharati Vidyapeeth (deemed to be) Dental College and Hospital, Navi Mumbai, Maharashtra, India, between November 2020 to December 2021. Sixty freshly extracted human mandibular premolar with straight and oval canals standardised with Cone Beam Computed Tomography (CBCT) were prepared with ProTaper next files and were assigned to two groups for obturation with gutta-percha using AH Plus and iRoot SP sealer respectively. Quality of obturation was confirmed with CBCT. After one month, retreatment was carried with V-Blue files and percentage of remaining obturating material was were evaluated before and after retreatment through micro-CT imaging. Two sample means and Kolmogorov Smirnov test were used to analyse data. Results: Data of all the samples from the micro-CT evaluation indicated that the mean volume of the initial filling material did not differ significantly among AH Plus sealer and iRoot SP sealer group (p>0.05). Percentage of residual volume of AH Plus sealer (0.02%) was lower than that of iRoot SP sealer group (0.06%) and this difference was statistically significant (p<0.05). Conclusion: Considerable amount of iRoot SP sealer remained after retreatment using V-Blue file as compared with AH Plus sealer.