Characteristic of Locally-made Nickel-Titanium Wire

Objectives: To investigate the characteristic of locally made NiTi wire and compare with the commercial NiTi orthodontic archwire.
Methods: The NiTi wire used in this study was the locally made NiTi wires produced by King Mongkut University of Technology Thonburi (KMUTT). The characteristic NiTi wire samples were tested the chemical composition by an Electron Probe Microanalysis (EPMA), the phase transformation by a Differential Scanning Calorimeter (DSC) and the three-point bending for tensile test by the Universal Testing Machine (Instron).
Statistical Analysis: The Mann-Whitney U test was employed to analyze and compare the data.
Results: The chemical composition of locally made NiTi wire is Ni, Ti and Cr. There were significant differences(p<0.05) in at.% of Ni, Ti, and Cr composition between locally made NiTi wire wire and commercial archwire. The transformation temperature is 35.84^oC for Ms compare to commercial 23 ^oC and 40.5^oC for Af compare to commercial 28.25 ^oC. For the three point bending test in terms of percentage recovery, stress plateau and stress hysteresis were 93.89 %.17.66 N and 10.74 N, respectively compared with commercial NiTi 97.96%, 13.52 N and 7.12 N, respectively. There was a significant(p<0.05) difference in mechanical properties of locally-made wire compare to commercial NiTi archwire except stress hysteresis.
Conclusions: Based on the results of this study, the characteristic of the locally made NiTi wire get the properties of NiTi wire, however it cannot get the properly characteristic same as the commercial NiTi archwire. This pilot study provides useful information for the further development of locally made NiTi archwires.