Efficacy of Two Ni-Ti Retreatment Systems and Hand Files in Removing Gutta-Perchaand Sealer from Root Canals Filled with Three Different Types of Sealers

This study was undertaken to evaluate the efficiency of two rotary nickel titanium instruments and hand instrumentation in removing gutta-percha and sealer from ischolar_main canals. 63 extracted human single ischolar_mained premolars were instrumented with K-files and filled using lateral compaction of guttapercha (GP) and three different sealers. The teeth were randomly divided into three experimental groups of 21 specimens each. Removal of gutta-percha was performed with R-Endo retreatment files, Mtwo retreatment files and Hedstrom files. Time to reach working length and to eliminate filling material was also recorded. The specimens were sectioned for evaluation of the area of the remaining gutta-percha/sealer under stereomicroscope at 6X magnification. Photographs were taken for further analysis using computer image analysis program. The results were statistically analyzed using Analysis of variance (ANOVA) and Tukey's honestly significant difference test. The R-Endo retreatment system resulted in a smaller percentage of canal area covered by residual GP/sealer than in other groups, a significant difference was found between R-Endo and Mtwo group and between Hedstrom groups (p < 0.001). The Mean operating time was minimum with R-Endo group while it was found to be maximum with hand files. It was concluded that all test techniques left gutta-percha/sealer remnants within the ischolar_main canal. The R-Endo retreatment files and Mtwo retreatment files system proved to be an efficient method for removing gutta-percha and sealer from single ischolar_mained premolars.