Bednar J R, Gruendeman G W, Sandrik J L
Department of Orthodontics, Loyola University School of Dentistry, Chicago.
Am J Orthod Dentofacial Orthop. 1991 Dec;100(6):513-22. doi: 10.1016/0889-5406(91)70091-A.
An in vitro study of simulated canine retraction was undertaken to evaluate the difference in frictional resistance between stainless steel arch wires and steel and ceramic brackets with elastomeric, steel, and self-ligation. Each bracket slot was 0.018 x 0.025 inch. The arch wires used were 0.014-inch, 0.016-inch, 0.018-inch, 0.016 x 0.016-inch, and 0.016 x 0.22-inch stainless steel. A testing apparatus was designed to attempt to simulate the clinical situation in which teeth tip slightly while they slide along the arch wire. Under these testing conditions, the self-ligating steel bracket did not demonstrate less friction than the elastic or steel-ligated stainless steel brackets. For most wire sizes, elastomer-ligated ceramic brackets demonstrated the greatest friction when compared with other bracket/ligation technique combinations. The clinical significance of this study becomes apparent when stainless steel brackets are used on the posterior teeth and ceramic brackets are used on the anterior teeth. If sliding mechanics are used, the anterior teeth may be more resistant to movement than the posterior teeth because of the greater friction of the ceramic brackets. This could result in more posterior anchorage loss than would be expected if only one type of bracket were used.
进行了一项模拟犬牙后移的体外研究，以评估不锈钢弓丝与采用弹性结扎、钢丝结扎和自结扎的金属及陶瓷托槽之间的摩擦阻力差异。每个托槽槽沟为0.018×0.025英寸。使用的弓丝为0.014英寸、0.016英寸、0.018英寸、0.016×0.016英寸和0.016×0.22英寸的不锈钢弓丝。设计了一种测试装置，试图模拟牙齿在沿弓丝滑动时轻微倾斜的临床情况。在这些测试条件下，自结扎金属托槽的摩擦力并不比弹性结扎或钢丝结扎的不锈钢托槽小。对于大多数弓丝尺寸，与其他托槽/结扎技术组合相比，弹性结扎的陶瓷托槽显示出最大的摩擦力。当后牙使用不锈钢托槽而前牙使用陶瓷托槽时，这项研究的临床意义就变得明显了。如果采用滑动机制，由于陶瓷托槽摩擦力较大，前牙可能比后牙更难移动。这可能导致比仅使用一种托槽时预期更多的后牙支抗丧失。
