Análise comparativa do comportamento mecânico de fios retangulares de NiTi convencionais e termoativados

Abstract

The evolution of orthodontics allowed the use of new materials such as resins and orthodontic wires, which are improved every day to ensure the efficiency of orthodontic treatment, respecting the physiological limits of tooth movement. Thermal nickel-titanium wires emerged in order to ensure the creation of soft but effective forces to obtain the correct tooth movement. After the acceptance of these materials, different brands and models appeared on the market, and their use became common. Since different types of nickeltitanium wires (NiTi) are currently available in the market, this study aimed to analyzing and comparing aspects of the mechanical behavior of eight different types of NiTi wires, rectangular section 0.016 x 0.022´´, through the evaluation of mechanical properties in torsion tests. The intentions were to relate the torque magnitude generated by each type of wire and to point the differences between conventional and thermal NiTi wires which justify the clinic choice between one and the other. We could conclude that thermal wires had significantly lower maximum torque value than the conventional ones evaluated, suggesting its application to cases in which one wants more control over the force levels.