Micro-computed tomography evaluation of filling material removal by three reciprocating systems with different thermal treatments

Aim: This study compared the efficacy of three reciprocating systems with different heat treatments in removing obturator material from lower molar mesial canals. Methodology: The mesial canals of 18 lower molars were instrumented with ProTaper Next 25/0.06 and filled with gutta-percha and AHPlus. The teeth were randomly divided into three groups (n=6) according to the system used to remove the filling material: Reciproc (REC R25), Reciproc Blue (RECB R25) and Wave One Primary (WO). The desobturation was considered complete when the working length was reached, and remnants of obturator material were no longer found in the instrument and also in the canal walls, observed through the dental operating microscope. Results: The results were analyzed using Biostat 4.0 software. Shapiro-Wilk and ANOVA (Tukey) tests with a significance level of 5% were applied. The volume of obturator material decreased in the cervical and middle thirds after the use of REC, RECB and WO systems (P .05). In the apical third, there was no significant reduction in the remaining obturator material independent of the operating system (P>.05). Conclusions: REC, RECB and WO systems showed similarity in the removal of obturator material and were inefficient specifically in the apical third, showing the limitation of these systems in removing obturation material from curved canals.