自锁托槽和传统托槽摩擦力的实验研究

Study on the Frictional Resistance of Self-ligating Bracket versus Conventional Bracket.

目的:测量自锁托槽和传统托槽与正畸弓丝成不同接触角角度时沿着各种弓丝滑动时所需克服的摩擦力大小,分析托槽、接触角、弓丝材料对弓丝与托槽之间摩擦力的影响。方法:本实验用于检测的托槽包括自锁托槽(DamonⅢ,In-ovation)和传统金属直丝弓托槽,所有托槽均选用上颌第一前磨牙托槽。应用Instron8841万能材料测试机测量托槽沿着各种弓丝(0.016in镍钛丝、0.016in澳丝、0.018×0.025in镍钛丝、0.018×0.025in不锈钢丝)滑动时摩擦力的大小。改变托槽与弓丝之间的角度,测量托槽与弓丝成不同角度时(0°、3°、6°、9°)摩擦力的大小。结果:自锁托槽的摩擦力在各种角度下均明显小于传统托槽。随着接触角的增加,自锁托槽和传统托槽摩擦力均增大,不锈钢丝和澳丝比镍钛丝摩擦力增加得更迅速。结论:托槽的类型、弓丝的材料和尺寸、接触角的变化对弓丝与托槽间摩擦力有显著的影响。自锁托槽能明显减小摩擦力。

Objectives： To measure the frictional resistance between self- ligating or conventional bracket and arch - wire at different contact angles. To analyse the effect of bracket, angulation and arch - wire material on the friction between bracket and arch - wire. Methods. Brackets to be measured in this experiment were self - ligating brackets（ Damon Ⅲ, In -ovation） and conventional pre- adjusted metal bracket. They were upper first premolar brackets. Instron8841 universal testing machine was used to measure the frictional resistance between brackets and different kinds of arch - wires（0.016in Ni- Ti arch- wire, 0.016in Australian wire, 0. 018×0. 025in Ni- Ti arch- wire,0.018×0. 025in stainless steel wire）. Friction resistances were measured at different angulations（0°, 3°, 6°, 9°）. Results： The self-ligating bracket had a markedly lower friction than conventional bracket at all angulations. Following the increase of angulations, friction increased for both self- ligating bracket and conventional bracket . The increase of frictional resistance was more pronounced in the case of stainless steel and Australian wire than Ni - Ti wire. Conclusion ： Bracket design, wire material and size, and contact angle significantly influence the friction between bracket and wire. Self - ligating bracket can markedly reduce the friction.