Comparison of niti orthodontic archwires and a determination of the characteristic properties

Abstract

The aim of this paper was to analyse the characteristic properties of six different, commercially available nickel-titanium orthodontic wires with a diameter of 0.305 mm (0.014"). The characteristic properties were determined by using semi-quantitative EDX analyses, DSC analyses for a determination of the phase temperatures, and a tensile test to obtain the mechanical properties of the wires. The investigation of the chemical composition showed an equiatomic NiTi alloy. Analyses of phase temperatures showed that the nickel-titanium orthodontic wires were, in an austenitic microstructure, exhibiting a superelastic effect in the oral environment. The uniaxial tensile stress strain curves showed different values for the beginning and the end of the transformation range during the loading.