双槽沟托槽滑动阻力的实验研究

目的 评价模拟尖牙滑动时双槽沟托槽的滑动阻力,探讨临床应用双槽沟托槽的合适牵引力.方法 将粘有托槽的人工尖牙置于硅胶槽内,分别在10g、15g和20g力牵引下沿弓丝滑动.双槽沟托槽组中人工尖牙在双圆丝(直径0.016英寸和0.018英寸)支撑下移动.对照组为常规方丝托槽和方丝(0.016英寸×0.022英寸)组合.通过激光测距仪及相连计算机得到的牙齿移动速率,分析牙齿滑动时所受阻力的大小.结果 牵引力为10g力和15g力时,双槽沟托槽组平均移动速率较小.当牵引力增加到20g力,双槽沟托槽组平均速率大于常规托槽组.结论 在足够牵引力的作用下,双槽沟托槽配合双圆丝(直径0.016英寸和0.018英寸)组合的滑动阻力并不比常规托槽和0.016英寸×0.022英寸方丝组合大.

Experimental study in resistance to sliding in tein-slot bracket during simulated canine retraction

Objective To assess the resistance to sliding in twin-slot bracket during simulated canine retraction. Methods A silicone based simulation system of canine sliding was used. The canine bonded with twin-slot bracket was drawn along 0. 016 inch and 0. 018 inch round wires with the traction of 10 cN, 15 cN and 20 eN respectively. The canine bonded with conventional edgewise bracket sliding along a single 0. 016 inch x 0. 022 inch rectangular wire served as con- trol. The rate of the canine movement was tested by a laser displacement sensor to indicate the resistance between the bracket and the wire（s）. Results The rate of the canine movement in twin-slot bracket group was lower than the singleslot bracket with the traction of 10cN and 15cN. But when the force increased to 20cN, twin-slot bracket group confronted higher rate compared with single-slot bracket group. Conclusions With sufficient force, the twin-slot bracket engaged with 0.016 inch and 0.018 inch round wires encountered a decreasing resistance to sliding compared with the edgewise bracket engaged with 0.016 inch ×0.022 inch ss wire.