Rutchadakorn IsarapatanapongSurachai DechkunakornNiwat AnuwongnukrohNattiree ChiranavanitJulathep KajorchaiyakulAnak KhantachawanaMahidol UniversityThailand National Metal and Materials Technology CenterKing Mongkuts University of Technology Thonburi2018-05-032018-05-032011-09-23Applied Mechanics and Materials. Vol.87, (2011), 20-2516627482166093362-s2.0-80052934167https://repository.li.mahidol.ac.th/handle/20.500.14594/11888Objective: The study aimed to clarify the compositions of 14 brands of superelastic NiTi orthodontic wires. Materials and Methods: The compositions were analysed through scanning electron microscopy and energy-dispersive X-ray microanalysis. The wires were tested in differential scanning calorimetry to find the transitional temperature range. Results: The compositions were nickel (50.085%-51.605%), titanium (46.675%-48.140%), copper (0.995%-1.155%), aluminum (0.220%-1.325%), chromium (0%-0.275%) and iron (0%-0.030%). None contained cobalt. G & H, Ormco, AMDG, IMD, Smart, TruFlex, Force 1, NIC, Sentalloy, Ortho Supply and Flexwire were almost or completely austenitic in the oral environment, whereas Highland, Grikin and Unitex were a mixture of austenitic and martensitic phase. The wires showed austenitic finish temperatures ranging from 17°C to 59°C. Conclusions: The results show that NiTi orthodontic arch wires have differences in composition and phase transformation. This information is valuable to evaluate differences in NiTi orthodontic wires for clinical use. © (2011) Trans Tech Publications.Mahidol UniversityEngineeringConference PaperSCOPUS10.4028/www.scientific.net/AMM.87.20