Comparison of Four Ni-Ti Rotary Systems: Dental Students' Perceptions in a Multi-Center Simulated Study.

: Nickel-titanium (Ni-Ti) rotary instruments have significantly enhanced the efficiency and safety of root canal shaping. However, the variety of Ni-Ti systems, characterized by differences in alloy composition, taper design, and heat treatment, may influence their usability, particularly for novice operators. This study aimed to evaluate the perceptions of dental students using four Ni-Ti rotary systems (MTwo, SlimShaper Pro, ProTaper Gold, and HyFlex EDM) in a simulated environment. : Forty dental students from two universities participated in the study and completed a standardized preoperative training session. Root canal shaping was performed on resin teeth models, and an 11-item questionnaire was used to assess various parameters, including flexibility, ease of use, and the ability to maintain working length. : The results indicated significant differences in student feedback. SlimShaper Pro and HyFlex EDM were preferred for their flexibility, reduced resistance, and ease of instrument transitions, likely due to their smaller tapers and martensitic alloys. MTwo was rated the least flexible and more challenging to use. These findings underline the importance of user-friendly Ni-Ti systems in pre-clinical training to reduce procedural difficulties and operator stress. Further research should validate these findings in clinical settings to improve the training of novice operators.