A Comparison of Effectiveness of Conventional and Rotary NiTi Instruments in the Removal of Gutta-Percha during Root Canal Retreatment: A Randomized Ex-vivo Study

Aim: To compare the effectiveness of conventional and rotary NiTi files for Gutta-Percha (GP) removal in straight roots during retreatment root canal treatment (RCT), using manual Hedstrom files and ProTaper Universal System, respectively. Methods: It was an in-vitro experimental study using non-probability consecutive sampling. Sixty extracted single rooted maxillary and mandibular permanent teeth with straight canals were selected for this study. Following preparation, the root canals were filled with GP along with a sealer and kept for two weeks in a moist environment at room temperature. Thirty teeth were randomly allocated to the study and control groups each. GP removal was accomplished with Hedstrom files and Pro Taper retreatment files in group 1 and group 2, respectively. Digital radiographs were obtained using Kodak RVG digital radiography system software version VER.6.10.8.3-A and analyzed for the difference of opacities indicating residual GP. AutoCAD 2006 software was used to outline the root canal and the residual root filling. Independent sample t test was used to compare the total residual GP in both groups. Results: No significant difference in the residual root filling was observed following removal with conventional Hedstrom files versus ProTaper universal retreatment files. In both groups, the residual GP was confined to the apical third of the roots. Conclusion: ProTaper Universal Retreatment files and manual Hedstrom files are equally effective in the removal of GP in straight canals.