不锈钢托槽与钴铬合金托槽摩擦力对比研究

Evaluation of friction of conventional stainless and cobalt-chromium alloy brackets in various bracket-archwire combinations

目的探讨不锈钢托槽与钴铬合金托槽对正畸摩擦力的影响。方法在干燥条件下,按重复测量实验设计,各因素各水平完全组合,使用XF-Ⅰ型摩擦力测试仪,测试不同托槽-弓丝-结扎方式组合时在后牙段的动、静摩擦力。所得数据进行方差分析。结果在托槽与所有不锈钢弓丝组合中,钴铬合金直丝托槽产生的动、静摩擦力大于其它3种传统不锈钢直丝托槽,而不锈钢托槽间的摩擦力差别不大;0.018英寸圆丝、0.020英寸圆丝、0.018英寸×0.025英寸方丝、0.019英寸×0.025英寸方丝的动、静摩擦力值依次增大;弹力橡皮圈结扎的动、静摩擦力及动、静摩擦力平均百分比均大于不锈钢结扎丝。结论钴铬合金托槽不适合在滑动机制中应用;用0.019英寸×0.025英寸不锈钢方丝关闭间隙,应尽可能加强支抗控制;涉及托槽与弓丝间相对滑动时,不适合使用弹力橡皮圈这一结扎方式。

Objective To investigate the effects of conventional stainless and cobalt-chromium alloy brackets in various bracket-archwire combinations on the frictional resistance. Methods All factors and levels in this study were completely combinated according to repeated measurement experimental design. The static and dynamic friction of different combinations of preadjusted bracket-archwire-ligating methods in the buccal segments were tested in the dry state. The friction was tested by the XF-I testing machine. The data were analyzed statistically. Results The dynamic and static friction produced by cobalt-chromium alloy preadjusted brackets were higher than the other traditional stainless steel preadjusted brackets among all the combinations, as well, there was no obvious difference between the stainless steel preadjusted brackets. The static and dynamic friction of 0.018inch-inch stainless round wire,0.020-inch stainless round wire,0.018 × 0.025 inch stainless rectangular wire and 0.019inch × 0. 025 inch stainless rectangular wire were increased in order. Elastomeric ring ligature produced bigger friction and higher ratio of dynamic to static friction than the stainless steel ligature. Conclusion Cobalt-chromium alloy brackets is not appropriate for application in gliding movement mechanism. We should pay more attention to strengthen anchorage control in using 0.019inch × 0. 025 inch rectangular wire. Elastomeric ring hgature is not suitable for sliding of brackets and wires in the dry state.