Shaping Ability of Two M‑Wire and Two Traditional Nickel‑Titanium Instrumentation Systems in S‑Shaped Resin Canals

Aims: The aim of this study was to evaluate the shaping effects of two M‑wire and two traditional nickel‑titanium (NiTi) rotary systems in simulated S‑shaped resin canals.Subjects and Methods: Forty simulated S‑shaped canals in resin blocks were instrumented with two traditional (ProTaper, Sendoline S5) and two M‑wire (WaveOne, GT series X) NiTi systems according to the manufacturers’ instructions. Ten resin blocks were used for each system. Pre‑ and post‑instrumentation images were captured using a stereomicroscope and superimposed with an image program. Canal transportation, material removal, and aberrations were evaluated and recorded as numeric parameters.Statistical Analysis Used: Data were analyzed using one‑way ANOVA and post‑hoc Tukey tests with a 95% confidence interval.Results: There were significant differences between systems in terms of transportation and material removal (P < 0.05). Coronal danger zone was the most common aberration.Conclusions: Within the limits of this ex vivo study, it was found that the manufacturing methods (M‑wire or traditional NiTi) and kinematics (rotary or reciprocating motion) did not affect the shaping abilities of the systems. The extended file designs of highly tapered NiTi systems (ProTaper, WaveOne) resulted in greater deviations from the original root canal trace and more material removal when compared to less tapered systems (Sendoline S5, GT series X).Keywords: Canal Transportation, Endodontic Instruments, M‑wire, Nickel‑titanium, S‑curvatur