Department of Orthodontics, School of Dentistry, University of Athens, Greece.
Eur J Orthod. 2013 Oct;35(5):610-4. doi: 10.1093/ejo/cjs041. Epub 2012 Jul 24.
The aim of this study was to assess the effect of the moments generated with low- and high-torque brackets. Four different bracket prescription-slot combinations of the same bracket type (Mini Diamond® Twin) were evaluated: high-torque 0.018 and 0.022 inch and low-torque 0.018 and 0.022 inch. These brackets were bonded on identical maxillary acrylic resin models with levelled and aligned teeth and each model was mounted on the orthodontic measurement and simulation system (OMSS). Ten specimens of 0.017 × 0.025 inch and ten 0.019 × 0.025 inch stainless steel archwires (ORMCO) were evaluated in the low- and high-torque 0.018 inch and 0.022 inch brackets, respectively. The wires were ligated with elastomerics into the brackets and each measurement was repeated once after religation. Two-way analysis of variance and t-test were conducted to compare the generated moments between wires at low- and high-torque brackets separately. The maximum moment generated by the 0.017 × 0.025 inch stainless steel archwire in the 0.018 inch brackets at +15 degrees ranged from 14.33 and 12.95 Nmm for the high- and low-torque brackets, respectively. The measured torque in the 0.022 inch brackets with the 0.019 × 0.025 inch stainless steel archwire was 9.32 and 6.48 Nmm, respectively. The recorded differences of maximum moments between the high- and low-torque series were statistically significant. High-torque brackets produced higher moments compared with low-torque brackets. Additionally, in both high- and low-torque configurations, the thicker 0.019 × 0.025 inch steel archwire in the 0.022 inch slot system generated lower moments in comparison with the 0.017 × 0.025 inch steel archwire in the 0.018 inch slot system.
本研究旨在评估低扭矩和高扭矩托槽产生的力矩。评估了同一托槽类型（Mini Diamond® Twin）的四种不同托槽-槽沟组合：高扭矩 0.018 和 0.022 英寸，低扭矩 0.018 和 0.022 英寸。这些托槽被粘接到具有平齐和对齐牙齿的相同上颌丙烯酸树脂模型上，每个模型都安装在正畸测量和模拟系统（OMSS）上。在低扭矩和高扭矩 0.018 英寸和 0.022 英寸托槽中分别评估了 10 个 0.017×0.025 英寸和 10 个 0.019×0.025 英寸不锈钢方丝（ORMCO）。将方丝用弹性体结扎到托槽中，每个测量值在重新结扎后重复一次。分别对低扭矩和高扭矩托槽中产生的力矩进行了双因素方差分析和 t 检验。在 0.018 英寸托槽中，0.017×0.025 英寸不锈钢方丝在+15 度时产生的最大力矩在高扭矩和低扭矩托槽中分别为 14.33 和 12.95 Nmm。在 0.022 英寸托槽中，0.019×0.025 英寸不锈钢方丝产生的测量力矩分别为 9.32 和 6.48 Nmm。高扭矩和低扭矩系列之间记录的最大力矩差异具有统计学意义。高扭矩托槽产生的力矩高于低扭矩托槽。此外，在高扭矩和低扭矩配置中，0.022 英寸槽系统中较厚的 0.019×0.025 英寸不锈钢方丝产生的力矩低于 0.018 英寸槽系统中 0.017×0.025 英寸不锈钢方丝产生的力矩。
