Abstract
The aim of this study was to investigate the load-deflection of commercially available standard NiTi wires and Cu-NiTi alignment archwires. The load deflection of 0.014 '' Cu-NiTi from American Orthodontics and 0.014 '' NiTi wires from five manufacturers, namely, 3M Unitek, Forestadent, G&H, Modern Orthodontics and Ormco were compared using a three-point bending test. A total of 120 samples in 6 groups of 20 samples each were tested using a universal testing machine at the crosshead speed of 10 mm/min; with a 100 N load cell at a constant force of 60 g. One way ANOVA and multiple comparison of the mean difference between the different groups using Tukey's HSD post hoc analysis were performed. The Forestadent and 3M Unitek archwires showed the highest deflection of 0.54 +/- 0.17 mm and 0.54 +/- 0.19 mm, respectively. While the Modern Orthodontics archwires showed the least deflection of 0.25 +/- 0.07 mm. Archwires of the same dimensions, transition temperature, and material but of different brands do not show the same mechanical properties, but have varying activation and deactivation forces. Thus, it can be concluded that the 3M Unitek and Forestadent archwires exerted low forces, which is desirable for orthodontic tooth movement. The Cu-NiTi archwires showed no superior properties compared to the conventional NiTi archwires.