EFFICACY OF THREE DIFFERENT RETREATMENT FILE SYSTEMS FOR GUTTA-PERCHA REMOVAL USING CONE BEAM COMPUTED TOMOGRAPHY

Introduction: The maximum ability of retreatment files to remove defective obturation materials is very important during endodontic retreatment. Aim of the study: The purpose of this study was to compare the efficiency of three different retreatment systems in root canal filling removal using chloroform as solvent. Materials and Methods: Thirty six extracted single rooted mandibular human premolars were used in this study following appropriate institutional ethical consent. Teeth were accessed and prepared chemo-mechanically to a standard working length of 17mm using Revo-S files. Obturation was done with lateral condensation using Total Fill bioceramic sealer and gutta percha. Teeth were randomly divided into three groups (n=12) according to retreatment files used: ProTaper-D group, R-ENDO group and M-Two-R group using Chloroform as solvent. Specimens were labeled then preoperative and postoperative CBCT scans were conducted and volume of remaining obturation material was measured by Osirix 32-bits software to be compared. Data were collected and statistical analysis was done where P value was set as P< 0.05. Results: All systems significantly removed gutta percha. However, none of the used files completely removed the root canal filling material from the canals. The Protaper D group left significantly more root canal filling material than the M-Two R and R-Endo groups (P <0.05). No statistically significant difference was found between the M-Two R and R-Endo groups (Wilcoxon test used, P<0.05). ProTaper D left more remnants in the coronal third (18.48%) showing statistically significant difference with the other groups. No Statistically significant differences were found at the middle or apical thirds between all groups (Friedman, Kruskal-Wallis tests used, P<0.05). Conclusion: The R-Endo and M-two R were more effective in removing root canal filling material than the ProTaper D.