Department of Orthodontics, University of Messina, Italy.
Eur J Orthod. 2009 Dec;31(6):643-6. doi: 10.1093/ejo/cjp054. Epub 2009 Oct 1.
The aim of this in vitro study was to evaluate the frictional forces between bracket and archwire that included three passive self-ligating brackets (Damon SL2 SDS). The brackets were individually bonded to a brass mount using a preformed 0.021 x 0.025 inch stainless steel wire jig in order to exclude adverse tipping or torsion. The central bracket was positioned 1 mm higher than the others, in order that the three brackets were vertically unaligned. Thirty-six similar set-ups including in total 108 brackets were investigated using the same wire: copper (nickel-titanium) 0.014 inches. A testing machine was designed and constructed to measure the frictional forces between the wire and the three-bracket set-up. Twelve set-ups were tested to measure kinetic frictional forces between the wire and unaligned passive self-ligating brackets used in the closed position. The frictional properties of two sets of 12 three-bracket set-ups (control) were tested and measured with an open slide and conventional ligation. A stainless steel ligature wire was used in the former, while elastomeric modules were employed in the latter. One-way analysis of variance showed a significant effect of ligation mode on the frictional properties of the three-bracket set-ups (P < 0.001). Post hoc pairwise comparison showed that the frictional forces arising from passive self-ligation were significantly lower (P < 0.01) than those resulting from elastic ligation. The same result was achieved when comparing self-ligation and metallic ligation (P < 0.01). No significant difference was found when comparing elastic and metallic ligation.
本体外研究的目的是评估包含三个被动自锁托槽（ Damon SL2 SDS ）的托槽和弓丝之间的摩擦力。将托槽分别用预成型的 0.021 x 0.025 英寸不锈钢丝夹具固定在黄铜支架上，以排除不利的倾斜或扭转。中央托槽的位置比其他托槽高 1 毫米，以便三个托槽垂直不对齐。使用相同的线（铜（镍钛）0.014 英寸）研究了总共 108 个包括 36 个相似设置的托槽。设计并构建了一台试验机来测量线与三托槽装置之间的摩擦力。测试了 12 个设置，以测量在关闭位置使用未对准的被动自锁托槽时线与线之间的动摩擦力。用打开的滑座和传统结扎测试和测量两组 12 个三托槽装置（对照）的摩擦特性。前者使用不锈钢结扎丝，后者使用弹性模块。单向方差分析显示结扎方式对三托槽装置的摩擦特性有显著影响（P <0.001）。事后两两比较表明，被动自锁产生的摩擦力明显低于弹性结扎（P <0.01）。当比较自锁和金属结扎时也得出了相同的结果（P <0.01）。当比较弹性结扎和金属结扎时，没有发现显著差异。
