Comparative Evaluation of Canal Transportation and Centering Ability of ProTaper Next, NeoNiTi, and R-Motion by CBCT Analysis in the Curved Root Canals of Permanent Mandibular First Molar: An In Vitro Study

Background: The success of root canal therapy hinges on various factors, with biomechanical preparation standing out as a crucial step. Equally significant is the meticulous preservation of the canal’s natural shape, as any deviation from it can lead to complications such as canal aberrations or transportation. The aim of the study was to evaluate the canal transportation and canal centering ability of ProTaper Next (PTN), NeoNiTi, and R-Motion (RM) file systems using cone-beam computed tomography (CBCT). Methods: Thirty human mandibular molar roots with an angle of curvature between ۱۰۰ and ۲۰۰ were chosen into three groups of ten samples each from the pool of collected samples that met the inclusion and exclusion criteria, including PTN (group I), NeoNiTi (group II), and RM file systems (group III). To achieve reproducibility of pre- and post-operative CBCT scans and to ease instrumentation, the tooth was placed in a template created using silicon impression material. Using CBCT software, pre- and post-instrumentation pictures were obtained from the apex at three different levels (۳ mm, ۶ mm, and ۹ mm). One-way analysis of variance and post hoc analysis were used to evaluate the amount of transportation and centering ability. Results: RM demonstrated better canal centering ability than PTN and NeoNiTi at ۳ mm and ۶ mm, but there was no statistically significant difference in canal transportation between the three groups at levels of ۳ mm, ۶ mm, and ۹ mm from the apex. Conclusion: PTN, NeoNiTi, and RM all exhibited similar behaviour under the study’s in-vitro conditions in terms of canal transportation and centering ability. However, the RM group outperformed the other systems in terms of both canal transportation and centering ability, with NeoNiTi and PTN systems coming in second and third, respectively.