Objective: To compare the dynamic cyclic fatigue resistance of nickel-titanium systems under two different axial kinematic motions in J-shaped canals at body temperature.
Methods: TG6 T1 and MTF T1 were operated using an E-Connect S motor set to continuous rotation (300 rpm). The artificial canal was submerged in an oil bath at body temperature. The experiment consisted of two axial kinematics: continuous up-and-down motion and progressive pecking motion on both TG6 T1 and MTF T1. The number of cycles to failure (NCF) was calculated and recorded. Data were analyzed using the independent t-test (p < 0.05).
Results: In both the continuous up-and-down motion and progressive pecking motion, TG6 T1 exhibited significantly higher NCF than MTF T1 (p < 0.001). When comparing the two axial motions, there was no statistically significant difference in NCF for both TG6 T1 and MTF T1.
Conclusions: Instruments manufactured with Gold heat-treated NiTi alloy demonstrated significantly better fatigue resistance compared to those made from conventional NiTi alloy. Alterations in the dynamic axial kinematics did not show a significant difference in the fatigue lifespan of the tested replica-like systems.