A comparative evaluation of canal transportation and centering ability of 3 different rotary file systems in oval canals: An in vitro CBCT study

Achieving proper canal shaping in oval root canals is a significant challenge in endodontics, as anatomical variations often lead to procedural errors such as canal transportation and poor centering. Sixty extracted mandibular premolars with standardized root length and confirmed oval canals were randomly assigned into three groups (n=20 each) and instrumented according to manufacturer's protocols. CBCT scans at 3 mm, 6 mm and 9 mm from the apex were analyzed for centering ratio and canal transportation, with results compared using one-way ANOVA (p<0.05). Hyflex CM demonstrated the best centering ability at 9 mm mesiodistally, Jizai showed the least transportation at the same level and One Curve performed better at 3 mm buccolingually. Thus, we show that rotary file systems differ in their ability to maintain canal anatomy and instrument selection plays a crucial role in achieving optimal root canal shaping.