Department of Orthodontics, Nihon University School of Dentistry, Tokyo, Japan.
Eur J Orthod. 2012 Jun;34(3):374-80. doi: 10.1093/ejo/cjr022. Epub 2011 May 13.
The torque moment generated by third-order bends is important for tooth movement. The purpose of this study was to measure the torque moment that can be delivered by various archwire and bracket combinations at the targeted tooth. Stainless steel (SS) upper brackets with 0.018 and 0.022 inch slots, two sizes of nickel-titanium (Ni-Ti) alloy wires, and three sizes of SS wires for each bracket were used. The wire was ligated with elastics or wire. The torque moment delivered by the various archwire-bracket-ligation combinations was measured using a torque gauge. Statistical analysis was undertaken using analysis of variance (multiple comparison tests and post hoc using Tukey's honestly significant difference test. The torque moment increased as the degree of torque and wire size increased. There was no significant difference in torque moment between the SS and Ni-Ti wires at lower or higher than 40 degrees torque. The torque moment with wire ligation was significantly larger than that with elastic ligation with 0.016 × 0.022 and 0.017 × 0.025 inch Ni-Ti wires in the 0.018 inch slot brackets and the 0.017 × 0.025 and 0.019 × 0.025 inch SS and Ni-Ti wires in the 0.022 inch slot brackets. However, there was no significant difference in torque moment between either ligation method when using the full slot size wires.
第三类弯曲产生的转矩力矩对牙齿移动很重要。本研究的目的是测量各种弓丝和托槽组合在目标牙齿上产生的转矩力矩。使用了带有 0.018 和 0.022 英寸槽的不锈钢（SS）上托槽、两种尺寸的镍钛（Ni-Ti）合金丝以及每种托槽的三种尺寸的 SS 丝。用弹性体或金属丝结扎丝。使用扭矩计测量各种弓丝-托槽-结扎组合产生的扭矩力矩。使用方差分析（多重比较检验和 Tukey 的诚实显著差异检验进行事后检验）进行统计分析。随着扭矩和线材尺寸的增加，扭矩力矩增加。在低于或高于 40 度扭矩时，SS 和 Ni-Ti 线材的扭矩力矩没有显著差异。在 0.018 英寸槽托槽中，用 0.016×0.022 和 0.017×0.025 英寸 Ni-Ti 线材以及在 0.022 英寸槽托槽中用 0.017×0.025 和 0.019×0.025 英寸 SS 和 Ni-Ti 线材进行弹性结扎时，用金属丝结扎的扭矩力矩明显大于弹性结扎，而在使用全槽尺寸线材时，两种结扎方法的扭矩力矩没有显著差异。
