Comparison of Time Required by D-RaCe, R-Endo and Mtwo Instruments for Retreatment: An in vitro Study.

INTRODUCTION To evaluate and compare the amount of time required by three rotary NiTi instruments in removing gutta-percha from root canal during retreatment with hand file as control. MATERIALS AND METHODS Eighty human mandibular premolars with single straight root canals were prepared and obturated by cold lateral condensation with gutta-percha and AH Plus sealer. After two weeks, the 80 teeth were divided into one control group and 3 retreatment groups (n = 20 each). Gutta-percha was removed using H-files, the D-RaCe, or the Mtwo or the R-Endo retreatment systems. Retreatment time was calculated using stopwatch. RESULTS D-RaCe and Mtwo required significantly less time than R-Endo and hand file. Hand file took maximum time, which was significantly slower than all groups. However, D-RaCe and Mtwo retreatment time was statistically insignificant. CONCLUSION D-RaCe and Mtwo remove gutta-percha faster than R-Endo and Hand files.