Evaluation of canal transportation and centering ability in mesiobuccal canals of maxillary molars using two Ni-Ti file systems: An ex-vivo micro-computed tomographic study

Abstract

Aim: This study aims to evaluate and compare the canal transportation and centering ability of two nickel–titanium file systems, ProTaper Next and WaveOne Gold, in comparison with ProTaper Universal in mesiobuccal canals of maxillary molars using micro-computed tomography. Materials and Methods: Seventy-five permanent maxillary first and second molars having mesiobuccal canals with curvatures between 20° and 30° were selected and subjected to pre-operative micro-computed tomographic scans. They were then divided into three groups (n = 25) based on the file system to be tested: Group 1-ProTaper universal (control), Group 2: ProTaper Next, and Group 3-WaveOne Gold. Access cavities were prepared, following which each specimen was instrumented using the specific file system. Post-instrumentation micro-computed tomographic scans were then carried out for each specimen. Pre- and post-instrumentation measurements of mesiobuccal canals were performed using the ImageJ 1.8.0 software. Canal transportation and centering ratio were calculated at three cross-section levels that corresponded to 3-mm, 6-mm, and 9-mm distance from the apical end of the root. The data obtained were then subjected to statistical analysis using ANOVA and Tukey's post-hoc tests. Results: It was seen that WaveOne Gold caused the least overall canal transportation and exhibited the highest centering ability, followed by ProTaper Next and ProTaper Universal, though the difference was not significant. Furthermore, there was no significant difference between the canal transportation and centering ability of ProTaper Universal, ProTaper Next, and WaveOne Gold at all three levels. Conclusion: None of the systems evaluated exhibited perfect centering ability and zero canal transportation. All file systems caused root canal transportation and minor changes in the root canal anatomy.