Lock-loose托槽与传统托槽摩擦力特性的比较研究

Comparison of friction force between Lock-loose bracket and traditional bracket

目的在干燥和人工唾液环境中测量Lock-loose托槽结扎中间翼和结扎全翼时与弓丝之间滑动摩擦力和静摩擦力的大小,并与传统四翼托槽和自锁托槽进行对比。方法应用原子力显微镜观察不锈钢弓丝与不同托槽摩擦前后的表观形貌。选用Lock-loose托槽、传统四翼托槽和自锁托槽,分别与0.406 4 mm、0.457 2 mm不锈钢圆丝和0.457 2 mm×0.634 9 mm、0.482 6 mm×0.634 9 mm不锈钢方丝组合,其中Lock-loose托槽使用结扎中间翼和结扎全翼两种结扎方式。使用电子万能力学实验机测量干燥和人工唾液两种环境下弓丝在托槽内滑动的动、静摩擦力。结果不同尺寸弓丝与不同托槽摩擦前后的表面粗糙度无明显差异(P>0.05);Lock-loose托槽结扎中间翼与4种弓丝组合的动、静摩擦力均接近于0,与传统四翼托槽有明显差异(P<0.05);与0.457 2 mm×0.634 9 mm不锈钢方丝组合时,Lock-loose托槽结扎全翼可以获得最大动、静摩擦力,与传统四翼托槽和自锁托槽的差异有统计学意义(P<0.05);人工唾液环境中的摩擦力小于干燥环境中的摩擦力(P<0.05)。结论 Lock-loose托槽可以通过不同的结扎方式调节并获得临床所需的摩擦力,有效解决了低摩擦力与强支抗控制的矛盾问题。

Objective Frictions of Lock-loose brackets with ligated main wings or all six wings were measured as they slid along archwires in dry and artificial saliva environments.The Lock-loose brackets were then compared with traditional brackets and self-ligating brackets.Methods The surface states of the stainless steel archwires were observed with atomic force microscopy before and after mechanical traction.The Lock-loose brackets,traditional brackets,and self-ligating brackets used in this study were composed of 0.406 4 and 0.457 2 mm stainless steel round archwires and 0.457 2 mm×0.634 9 mm and 0.482 6 mm×0.634 9 mm stainless steel rectangular archwires.Two different ligating methods were applied to the Lockloose brackets,i.e.,main wings ligated and all six wings ligated.Frictions were measured by using an electronic universal testing machine.Results No significant differences were found between the roughness of different archwires before and after mechanical traction in different brackets（P〉0.05）.When the main wings of the Lock-loose brackets were ligated,the frictions of the four different stainless steel archwires were close to zero,and the difference with frictions of traditional brackets was significant（P〈0.05）.When using 0.457 2 mm×0.634 9 mm rectangular archwires,maximum friction（P〈0.05;significantly different from those of other brackets） was reached when all six wings of the Lock-loose brackets were ligated.Frictions in the dry state were higher than those in the wet state（P〈0.05）.Conclusion The Lock-loose brackets can adjust the friction efficiently with different ligating methods,thus solving the problem of low friction and strengthening anchorage.