@Article{, title={Load-deflection characteristics and force levels of coated nickel titanium orthodontic archwires}, author={Hind Dawood Abaas هند داود عباس and Akram Faisal Al-Huwaizi اكرم فيصل الحويزي}, journal={Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد}, volume={27}, number={2}, pages={154-157}, year={2015}, abstract={Background: Coated archwires have been introduced to improve esthetics during orthodontic treatment. Theaim ofthe present study was to evaluate and compare the load–deflection characteristics and force levels of six brands ofcoated nickel titanium orthodontic archwires using palatal and gingival deflection.Materials and methods: Ten round wires (0.016 inch) and ten rectangular wires (0.019x0.025 inch) were obtained fromeach of six brands (G&H, Opal, Ortho Technology, Dany, Hubit and Astar Companies). The load-deflection propertiesof these archwires were evaluated by the modified bending test usinga readymade dental arch model in bothpalatal and gingival directions at 37°C temperature using a universal material testing machine. Forces generated atmaximum loading of 2mm and at unloading of 1.5mm were measured.Results: All the wires showed hysteresis and significant differences in their load deflection curves, but thesedifferences were more evident in round wires than in rectangular wires where G&H wires showed the widest loadingunloadingdeflection curves. The maximum loading force of round wires in gingival deflection were higher than bypalatal deflection. The force decline during unloading (plateau gap) ranged between 18 to 34% for round wires and17 to 37% for rectangular wires.Conclusion: Coated epoxy wires (G&H, Opal, Astar and Ortho Technology) produced lower forces compared topolymer (Dany) and Teflon (Hubit) coated round and rectangular archwire

} }