Sims A P, Waters N E, Birnie D J
Department of Oral Surgery and Orthodontics, Royal Naval Hospital, Haslar, Gosport, Hampshire, U.K.
Br J Orthod. 1994 Nov;21(4):367-73. doi: 10.1179/bjo.21.4.367.
Friction in fixed appliance systems has received considerable attention in recent literature, although that attributable to varying second order (tip) and third order (torque) adjustments in either the bracket or the archwire has not been fully investigated. The ex vivo study of 0.022 x 0.028-inch slot Minitwin, Activa, and Standard Straight Wire brackets investigates friction when known values of tip or torque were applied to 0.018 x 0.025-inch stainless steel wires. The resistance to sliding of the wire through the ligated brackets was measured on a vertically-mounted Instron testing machine. The results showed that the self-ligating Activa brackets consistently produced less friction than the other conventionally tied brackets. Minitwin brackets were slightly more resistant to movement than the Standard brackets during torquing, but the converse was found when tip was applied. Increasing tip and torque (ranges tested 0-6 degrees and 0-25 degrees, respectively) produced almost linear increases in friction for all brackets, although increasing tip had the more profound effect on friction, particularly in Activa brackets.
固定矫治系统中的摩擦力在最近的文献中受到了相当多的关注，尽管在托槽或弓丝中由于不同的二阶（倾斜）和三阶（转矩）调整所产生的摩擦力尚未得到充分研究。一项针对0.022×0.028英寸槽沟的Minitwin、Activa和标准直丝托槽的体外研究，在将已知的倾斜或转矩值施加于0.018×0.025英寸不锈钢丝时，对摩擦力进行了研究。通过垂直安装的英斯特朗试验机测量钢丝穿过结扎托槽的滑动阻力。结果表明，自锁式Activa托槽产生的摩擦力始终比其他传统结扎托槽小。在施加转矩时，Minitwin托槽比标准托槽对移动的阻力稍大，但在施加倾斜时情况则相反。增加倾斜和转矩（分别测试的范围为0 - 6度和0 - 25度）会使所有托槽的摩擦力几乎呈线性增加，尽管增加倾斜对摩擦力的影响更为显著，尤其是在Activa托槽中。
