Comparison of the Time Required by Six Different Retreatment Techniques for Retrieval of Gutta-Percha: An In Vitro Study

Abstract Objective  A retreatment is a conservative approach than periapical surgery in case of failed root canal treatment. Retreatment techniques that are efficient and faster should be the main concern to treat endodontic failure. This study aimed to compare the time required by various hand and rotary retreatment systems for the retrieval of gutta-percha (GP) from root canals. Materials and Methods  A total of 120 extracted single-rooted premolar teeth with straight canals were chosen. Biomechanical preparation was completed using the Step-Back approach keeping the master apical file size 35. Then, teeth were down-packed and back-filled with System B device, along with AH Plus sealer. The teeth were categorized into six groups ( n  = 20) at random as per techniques applied for retrieval of GP: group I hand instrumentation (Hedstrom files and Gates-Glidden drills); group II ProTaper Universal Retreatment (PTUR) system; group III Mtwo Retreatment (Mtwo R) system; group IV D-RaCe; group V R-Endo; and group VI Mani Gutta Percha Remover (NRT-GPR). A chronometer was used to measure the time required for retrieval of GP. Data were examined by comparative evaluation of one-way analysis of variance and chi-square test. Results  Among all the retreatment techniques used, D-RaCe was faster in GP retrieval than other groups. NRT-GPR system also took less time than other groups except for the D-RaCe system. The Mtwo R system was the slowest among all groups. Conclusion  D-RaCe retreatment instruments required extensively less time for retrieval of GP than other groups ( p  < 0.001).