Read-Ward G E, Jones S P, Davies E H
Department of Orthodontics, Royal Bournemouth Hospital, U.K.
Br J Orthod. 1997 Nov;24(4):309-17. doi: 10.1093/ortho/24.4.309.
This ex-vivo study compared the static frictional resistance of three self-ligating brackets with a conventional steel-ligated Ultratrimm bracket. The effects of archwire size (0.020, 0.019 x 0.025 and 0.021 x 0.025-inch), bracket/archwire angulation (0, 5 and 10 degrees) and the presence of unstimulated human saliva were investigated. The study demonstrated that both increases in wire size and bracket/archwire angulation resulted in increased static frictional resistance for all bracket types tested, with the presence of saliva having an inconsistent effect. Mobil-Lock Variable-Slot had the least friction for all wires for 0 degree angulation. However, with the introduction of angulation, the values were comparable to those of the other brackets. Activa brackets had the second lowest frictional resistance, although high values were found with 0.019 x 0.025-inch wires. SPEED brackets demonstrated low forces with round wires, although with rectangular wires or in the presence of angulation, friction was greatly increased. Ultratrimm brackets produced large individual variation, confirming the difficulty in standardizing ligation force, although under certain conditions, significantly larger frictional forces were observed. In conclusion, self-ligating brackets showed reduced frictional resistance in comparison to steel ligated brackets only under certain conditions.
这项体外研究比较了三种自锁托槽与传统的金属结扎Ultratrimm托槽的静摩擦阻力。研究了弓丝尺寸（0.020、0.019×0.025和0.021×0.025英寸）、托槽/弓丝角度（0、5和10度）以及未刺激的人唾液的存在对其的影响。研究表明，对于所有测试的托槽类型，弓丝尺寸和托槽/弓丝角度的增加都会导致静摩擦阻力增加，而唾液的存在产生的影响并不一致。对于0度角度，Mobil-Lock可变槽在所有弓丝上的摩擦力最小。然而，随着角度的引入，其数值与其他托槽相当。Activa托槽的摩擦阻力第二低，尽管在使用0.019×0.025英寸弓丝时发现摩擦力较高。SPEED托槽在使用圆形弓丝时摩擦力较小，尽管在使用方形弓丝或存在角度时，摩擦力会大大增加。Ultratrimm托槽产生了较大的个体差异，证实了标准化结扎力的困难，尽管在某些条件下，观察到了明显更大的摩擦力。总之，自锁托槽仅在某些条件下比金属结扎托槽显示出更低的摩擦阻力。
