Advantages of thermally activated nickel titanium wire: 1. Less pain for patients: This results from a gradual increase in force and eventually a light force. The controlled thermal activity prevents a sudden increase in force when eating hot drinks or hot food. The patient can relieve the excessive force by drinking cold water. 2. Brackets fall off and ceramic brackets break less: This is due to the gradually increasing light force. Such archwires are ideal for ceramic brackets. The archwire can maintain its martensitic state at low temperature, which helps to further reduce the initial force value and make the placement of the archwire easy. 3. Less arch wire breakage: Because it is softer than the austenitic arch wire, it is not easy to break after being stressed. 4 Reduced chair-side working time: Because of its large deformation range, it can reduce the adjustment times and the replacement times of the arch wire. 5. Shortening of treatment time: Preliminary studies have shown that early torque control and the use of light and sustained force can shorten the total treatment time, and the early use of rectangular wires in straight wire brackets can directly move the teeth to the ideal position. Shortcoming It can not effectively maintain the shape of the dental arch, and it is better not to use it to close the gap, because the force of the elastic ring and coil spring will deform the arch wire and tilt the teeth. In addition, although heat-activated nitinol wires can shorten chair-side working time, the time to move teeth is longer, and doctors should wait patiently for the archwire to fully play its role. Objective To compare the stiffness, elasticity, strength and fatigue resistance of Australian wire, American orthodontic wire, imitated Australian wire, domestic stainless steel wire and heat-treated domestic stainless steel wire, and to provide the basis for clinical rational selection of orthodontic wire. Methods The mechanical property of five kinds of orthodontic wires were tested and compared, including elastic modulus, elastic limit, rebound angle, tensile strength,nickel titanium wire, torsion strength and fatigue strength. Results The stiffness, elasticity, strength and fatigue resistance of five kinds of orthodontic wires were compared. Conclusion The steel wire should be selected according to the demand of different orthodontic time and the different characteristics of steel wire in clinic. Contact us Back to Sohu to see more Responsible Editor:. yunchtitanium.com