Mechanical Properties and Clinical Efficacy of Two Nickel-Titanium (NiTi) Archwires

Objective: to compare the changes of the mechanical properties measured by tensile test and three point bending test of two NiTi archwires (heat-activated and superelastic); when exposed to the oral conditions during the first three months of orthodontic treatment and to evaluated their clinical efficacy in lower arch crowding resolution in the anterior mandibular arch. Methods: Randomized clinical trial in 54 orthodontic patients with moderate crowding. They are going to be randomly assigned in to two intervention groups, each group with 27 patients. One group are going to be treated with heat-activated NiTi archwires and the other group with superelastic NiTi archwires. The patients are going to be followed up for three months and cast models will be taken every month. Measures of anterior lower arch crowding resolution are going to be taken by previously-calibrated operators. Six archwires of each group will be chosen at random and will have tensile test and three-point bending test and the mechanical properties are going to measure before and after its clinical use. The outcomes are going to be determined and compared between groups, with correspondent statistical test and the results are going to be analyzed.