Mechanical preparation of oval-shaped root canals in mandibular premolars with the TRUShape 3D Conforming File: a micro-computed tomography study

Endodontic treatment aims to prevent or eliminate apical periodontitis, an inflammatory disease caused by an infected root canal system. Central to endodontic treatment is chemo- mechanical root canal preparation: mechanical enlargement and shaping combined with chemical disinfection of the root canal system. An ever-changing armamentarium is used to perform and evaluate chemo-mechanical root canal preparation, “preparation” for short. The TRUShape 3D Conforming File is a novel instrument, whose unique design, an S-curve in the instrument’s long axis, may enhance preparation of non-round root canals. The purpose of this study was to evaluate the preparation ability of TRUShape compared to Vortex Blue (VB), an established endodontic instrument, when used in non-round root canals by three-dimensional (3D) analysis, namely micro-computed tomography (MCT)./

Thirty extracted, single-rooted human teeth with similar root canal size and curvature were assigned to two groups (N=15): TRUShape or VB. Root canals were prepared according to manufacturer’s instructions. Each specimen was scanned using a desktop MCT unit at three time intervals: pre-, mid-, and post-preparation. Two- and three-dimensional data sets were generated. Root canal volume and prepared or “treated” surface, and each instrument’s ability to remain centered in the root canal during preparation were statistically analyzed.

Root canal volumes increased similarly and significantly overall in the TRUShape and VB groups. Treated root canal surface was significantly larger in the TRUShape group. There was minimal difference in files’ centering ability.

This MCT study demonstrated the TRUShape 3D Conforming File to be effective in mechanical root canal preparation of single-rooted teeth with oval-shaped root canals.