Cleaning and Shaping Ability of Two Heat-Treated Rotary Ni-Ti Files: A Correlated Histological and CBCT Study

Objectives: the aim of the study was to compare the shaping and cleaning abilities of Race Evo and VDW. Rotate rotary files in extracted human mandibular molars. Materials and Methods: Sixty mesiobuccal canals, in mandibular first molars, with moderate curvature (15°–30°) were randomly assigned to two groups (n = 30): Group A (Race Evo #25/.04) and Group B (VDW.Rotate #25/.04). Shaping ability was assessed using CBCT at 3, 6, and 9 mm from apex, and cleaning efficacy was evaluated histologically by quantifying residual debris. Data were analyzed with a significance set at p ≤ 0.05. Kruskal-Wallis and Mann-Whitney tests have been applied for intra- and intergroup comparisons of image analysis results in cleaning assessment. Chi-square test assessed differences in canal transportation and centering. Results: Both systems-maintained canal anatomy within acceptable limits. VDW. Rotate exhibited better centering, whereas Race Evo showed fewer residual debris, with no significant differences between groups. A moderate negative correlation was observed between centering and debris in the VDW. Rotate group (r = –0.374, p = 0.027), suggesting better centering may enhance cleaning. Conclusion: Both rotary systems demonstrated comparable shaping and cleaning abilities and can be considered clinically safe and effective.