摘要目的 研究不同弓丝在不同托槽中滑动时,随弓丝与托槽倾斜成角的变化,滑动摩擦力的变化特点.方法 方法 选择两种被动式自锁托槽和两种主动式自锁托槽及传统直丝托槽分别与四种不同材质和尺寸的弓丝组合,使用自主研发设计的摩擦力测试仪测量以上弓丝在托槽中滑动时,弓丝与托槽倾斜成角变化时滑动摩擦力的大小及变化特点.结果 随托槽-弓丝倾斜角度增大,弓丝与托槽之间的滑动摩擦力也随之增大.使用0.014英寸(1英寸=25.4 mm)超弹性镍钛圆丝在四种自锁托槽中滑动时摩擦力值为(2.25～29.56)g,MBT直丝托槽的摩擦力值为(53.67～99.25)g,两者结果有显著性差异;使用0.019×0.025英寸不锈钢方丝与五种托槽组合时,自锁托槽与传统托槽摩擦力大小无显著性差异.结论 在正畸治疗的初始排齐阶段,自锁托槽可加快牙齿排齐速度;而治疗中后期自锁托槽并不能加快牙齿移动速度.

abstractsObjective To investigate the characteristics of frictional resistance to sliding between different archwires and brackets when presented with different angulations.Methods Two kinds of passive self-ligating brackets and two active self-ligating brackets and one conventional bracket were combined with 4 types of archwires.The resistance to sliding of each archwire-bracket group was measured at different angulations using self-invented friction testing apparatus.Results The sliding friction value increased with increasing anglulation.When coupled with 0.014" superelastic NiTi archwires,the sliding friction values of the four self-ligating brackets were (2.25～29.56) g,the MBT bracket was (53.67～99.25) g,there are significant differences.When coupled with 0.019 × 0.025" stainless archwires,There is no significant difference between these brackets.Conclusions The self-ligating brackets can accelerate tooth alignment significantly during early stage of orthodontic treatment than conventional bracket.But the difference was not significant at later stages of orthodontic.