A comparative study of four rotary NiTi instruments in preserving canal curvature, preparation time and change of working length

Abstract

The purpose of this ex vivo study was to compare working time, working length changes and shaping effects using ProTaper, ProFile, FlexMaster and Mtwo rotary instruments. A total of 96 mesiobuccal roots of the first maxillary molars were prepared using these instruments. Using pre and post-radiographs, canal curvature and working length were measured. In addition, the time required for canal preparation was recorded. Data was statistically analysed using one-way anova and Duncan's post-hoc tests. ProTaper significantly lessened the canal curvature (P < 0.001), and Mtwo rotary instruments took significantly less instrumentation time (P < 0.001). No significant difference was observed between the four groups in changing working lengths (P = 0.081). According to the results of the study, the Mtwo rotary instruments required significantly less instrumentation time, and the ProTaper significantly changed the canal curvature.