Micro-computed Tomographic Comparison of Nickel-titanium Rotary Versus Traditional Instruments in C-shaped Root Canal System

Introduction: The purpose of this study was to assess the efficacy of instrumentation of C-shaped canals with ProTaper rotary system and traditional instruments by using micro-computed tomography (micro-CT).

Methods: Twenty-four mandibular molars with C-shaped canals were selected in pairs and sorted equally into 2 groups, which were assigned for instrumentation by ProTaper rotary system (ProTaper group) or by K-files and Gates-Glidden burs (Hand Instrument group). Three-dimensional images were constructed by micro-CT. The volume of dentin removed, uninstrumented canal area, time taken for instrumentation, and iatrogenic error of instrumentation were investigated.

Results: Hand Instrument group showed greater amount of volumetric dentin removal and left less uninstrumented canal area than ProTaper group (P < .01). The time needed for instrumentation was shorter for ProTaper group than for Hand Instrument group (P < .05). No instrument breakage occurred in both groups, but more conspicuous procedural errors were detected in Hand Instrument group than for ProTaper group.

Conclusions: It was concluded that ProTaper rotary system maintained the canal curvature with speediness and few procedural errors, whereas traditional instrumentation can clean more canal surface.