Bai Ding, Gu Min, Zhang Jian
Department of Orthodontics, West China School of Stomatology, Sichuan University, Chengdu 610041, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2004 Mar;39(2):104-7.
To evaluate the properties of orthodontic rectangular arch wires in torsion.
To measure and analyze the torsional moments and angles of 0.46 mm x 0.63 mm rectangular orthodontic arch wires in single 0.022 inch bracket of the maxillary central incisor with a torsion measurement apparatus.
(1) The torsional stiffness of stainless steel arch wires, Chinese nitinol arch wires, 7.0 mm vertical loop arch wires, 3.0 mm and 6.0 mm horizontal loop arch wires is 4.909, 1.325, 4.137, 3.448 and 3.024 Nmm per degree, respectively. (2) The arch wires will be twisted 19.143, 36.832, 19.851, 21.812 and 22.418 degrees; respectively to obtain optimal force. (3) Vertical and horizontal loop decreased the torsional stiffness of the rectangular stainless steel arch wire.
The straight rectangular stainless steel arch wire is not well suitable for the torque control of the incisor. Loop design in arch wire is capable of decreasing torsional stiffness. The horizontal loop is more effective than vertical loop.
评估正畸矩形弓丝的扭转特性。
使用扭转测量装置测量并分析上颌中切牙单0.022英寸托槽中0.46毫米×0.63毫米正畸矩形弓丝的扭转力矩和角度。
（1）不锈钢弓丝、国产镍钛弓丝、7.0毫米垂直曲弓丝、3.0毫米和6.0毫米水平曲弓丝的扭转刚度分别为每度4.909、1.325、4.137、3.448和3.024牛毫米。（2）弓丝分别扭转19.143、36.832、19.851、21.812和22.418度可获得最佳力。（3）垂直曲和水平曲降低了矩形不锈钢弓丝的扭转刚度。
直的矩形不锈钢弓丝不太适合切牙的转矩控制。弓丝中的曲设计能够降低扭转刚度。水平曲比垂直曲更有效。
