Comparison of the High Cycle Fatigue Behavior of the Orthodontic NiTi Wires: An in Vitro Study

Objective: To compare the high-cycle fatigue behavior of four commercially available NiTi orthodontic wires. Material and Methods: Twelve wires, round, 0.016-in, three per brand, were selected divided into groups: G1 - Heat-activated NiTi, G2 Superelastic G3 Therma-Ti, G4 CopperNiTi. The atomic absorption spectrometry method was used to determine chemical composition investigated We also performed a test at three-point bending using universal testing machine for 1000 cycles in 35 °C water bath. For first thousandth cycle, average plateau load length determined unloading area force versus displacement diagram. In addition, we calculated difference between cycle (∆F), as well both cases (∆L). Results: According our results, there no significant differences each group (p>0.05) groups (p>0.05). Conclusion: There changing superelasticity property after fatigue.