Comparison of the efficacy of different Ni-Ti instruments in the removal of gutta-percha and sealer in root canal retreatment

Abstract

Aims: To evaluate and compare the efficacy of four rotary instrumentation systems in root canal retreatment and to determine retreatment time. Materials and Methods: To achieve the purpose of this study, canals of 60 distal roots in mandibular molar teeth were selected and randomly divided into four groups A, B, C and D (n = 15). Using step-back technique, the canals were prepared and filled with gutta-percha and AH Plus employing cold lateral compaction technique. The root filling material was removed with the following retreatment systems: Group A: Mtwo R, group B: D-RaCe, group C: ProTaper R and group D: R-Endo. In order to record retreatment time, a stopwatch was used. The samples were split longitudinally, examined under a stereomicroscope, photographed and assessed with AutoCAD software. Finally, the percentages of remaining filling material were calculated and the extracted data were analyzed using one-way ANOVA and Tukey HSD test. Results: All examined groups showed traces of remaining filling material within the canals. No statistically significant difference was found among the four groups in the coronal, middle, and apical thirds. The same result was obtained with regard to retreatment time (P > 0.05). However, within each one of the groups, significant difference was observed in the three regions (P < 0.05). Conclusions: Based on the findings of this study, none of the examined systems could completely remove root filling material from the root canals. However, they were all found to be effective in this regard. The most amount of remaining filling material was found in the apical third.

Keywords

• d-race
• mtwo r
• protaper r
• r-endo