Loftus B P, Artun J, Nicholls J I, Alonzo T A, Stoner J A
Department of Orthodontics, University of Washington, Seattle, USA.
Am J Orthod Dentofacial Orthop. 1999 Sep;116(3):336-45. doi: 10.1016/s0889-5406(99)70247-7.
Frictional forces during simulated sliding tooth movement were measured with a model that was representative of the clinical condition. The model allowed tipping of the tooth until contact was established between the arch wire and diagonally opposite corners of the bracket wings; it also allowed rotation until the wire contacted opposite corners of the ligature tie, or the buccal shield with self-ligating brackets, and the base of the slot. Conventional and self-ligating stainless steel brackets as well as conventional ceramic brackets, and ceramic brackets with a stainless steel slot, all with 0.022 inch bracket slot, were tested with 0.019 x 0.025 inch arch wires of stainless steel, nickel titanium, and beta titanium. Each of the 12 bracket-arch wire combinations was tested 10 times. No significant interaction was detected between brackets and arch wires (P = .89), but the bracket and arch wire effects were significant (P < .001). The pairwise differences between conventional and self-ligating stainless steel brackets and ceramic brackets with stainless steel slot were not significant. However, the conventional ceramic brackets generated significantly higher friction than the other brackets tested. Beta titanium arch wires produced higher frictional forces than nickel titanium arch wires, but no significant differences were found between each of the two and stainless steel arch wires. Attempts to identify differences in surface scratches of the arch wires produced by the different brackets were unsuccessful.
使用一个代表临床情况的模型测量模拟滑动牙齿移动过程中的摩擦力。该模型允许牙齿倾斜，直到弓丝与托槽翼的对角建立接触；它还允许旋转，直到弓丝接触结扎丝的对角，或自锁托槽的颊面护盾与槽沟底部。传统和自锁不锈钢托槽以及传统陶瓷托槽和带有不锈钢槽沟的陶瓷托槽，所有托槽槽沟均为0.022英寸，分别与0.019×0.025英寸的不锈钢、镍钛和β钛弓丝进行测试。12种托槽-弓丝组合中的每一种都进行了10次测试。未检测到托槽和弓丝之间有显著交互作用（P = 0.89），但托槽和弓丝的效应显著（P < 0.001）。传统和自锁不锈钢托槽以及带有不锈钢槽沟的陶瓷托槽之间的两两差异不显著。然而，传统陶瓷托槽产生的摩擦力明显高于其他测试托槽。β钛弓丝产生的摩擦力高于镍钛弓丝，但这两种弓丝与不锈钢弓丝之间均未发现显著差异。试图识别不同托槽在弓丝表面产生划痕差异的尝试未成功。
