Efficacy of Different Nickel-Titanium Instruments in Removing Gutta-percha during Root Canal Retreatment

Abstract

Introduction: The aim of this study was to compare the cleanliness of root canal walls after retreatment using ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), Twisted File Adaptive (TFA; Axis/SybronEndo, Orange, CA), Reciproc (PRC; VDW, Munich, Germany), and ProTaper Universal retreatment (PTR, Dentsply Maillefer) nickel-titanium systems and the time required for gutta-percha and sealer removal. Methods: Eighty human maxillary central incisors with single and straight root canals were instrumented up to #40.02 with manual K-files (Dentsply Maillefer) and obturated using the continuous wave of condensation technique. Removal of the gutta-percha and sealer was performed using 1 of the following nickel-titanium systems: PTN, TFA, RPC, or PTR. The teeth were sectioned, and digital images were captured. The photographs were analyzed using AutoCAD software (Auto desk, San Rafael, CA). Also, the total time required for gutta-percha removal was calculated by a chronometer. Results: The total retreatment time was significantly shorter in the PTR group compared with the other groups (P <.05). There was a significant difference between the groups according to the total residual guttapercha and sealer (P <.05). The PTN and PTR groups left significantly less gutta-percha and sealer remnant than the TFA and RPC groups (P <.05). Conclusions: Within the limitations of this study, the PTN and the PTR groups showed less residual gutta-percha and sealer than the TFA and RPC groups. The time required for guttapercha and sealer removal was similar for all the groups, except for the PTR group.