Mechanical properties of several NiTi alloy wires in three-point bending tests

Abstract

Objective: To clarify mechanical properties of 14 superelastic NiTi orthodontic wires by three-point bending tests. Materials and Methods: The three-point bending test was conducted with a midspan deflection rate of 5 mm/min under constant temperature range 36±1°C. Wires were deflected to 3.1 mm. All data were recorded during the unloading process at deflections 3, 2, 1 and 0.5 mm. to simulate the force a wire exerts as a tooth is moved into the dental arch from a position of malocclusion. Results: The delivered forces changed slightly when the deflection varied during loading and unloading. Sentalloy wire applied the lowest continuous force. Conclusions: Commercial wires may not behave similarly due to minor differences in the production process, and force varies greatly from brand to brand. NiTi wire brands must be selected carefully considering the severity of malocclusion and stage of orthodontic treatment. © (2011) Trans Tech Publications.