Canal Transportation, Centering Ability, and Dentin Removal after Instrumentation: A Micro-CT Evaluation

The aim of this study is to evaluate and compare root canal transportation, centering ability, and amount of dentin removed after root instrumentation with different rotary and reciprocating systems, using micro-computed tomography (micro-CT).

Forty curved mesial canals of lower molars were selected and divided into four experimental groups (n = 10) according to the system used: protaper next (PTN), wave one gold (WOG), prodesign logic (LOG), and vortex blue (VTX). The roots were scanned before and after instrumentation using micro-CT, with a 16 μm isotropic resolution.

Data were statistically analyzed using the Bioestat and the significance level was set at 0.05. For canal transportation, no significant differences were verified between the groups at 6 mm or 9 mm from the apex. At the apical third, LOG had a smaller mesial deviation when compared with PTN. A significant difference was found at the apical and coronal thirds, though with LOG having the best centering ability at the apical third and the worst one at the coronal third. All systems caused a greater wear at the coronal third (9 mm), decreasing at the apical one (3 mm), with statistically significant differences. LOG removed less dentin from the apical third (3 mm) than did the other instruments.

The systems evaluated presented different results for canal transportation, centering ability, and dentin removal at each third.

The systems were evaluated together to evaluate neither the marked dental deviations nor the long-term signifiers of the databases and they were evaluated within the limits of normality. Therefore, they can be used without risks of embrittlement of the dental roots.