a Postgraduate student, Department of Orthodontics, College of Dentistry, Yonsei University, Seoul, Korea.
Angle Orthod. 2014 Jan;84(1):177-83. doi: 10.2319/030313-179.1. Epub 2013 Jun 14.
To quantitatively analyze the surface roughness of the slot floors of three types of modern plastic brackets and to measure static frictional force during sliding mechanics in vitro.
Control groups comprised stainless steel brackets and monocrystalline ceramic brackets. Test groups comprised three types of 0.022-in slot, Roth prescription, plastic, maxillary right central incisor brackets. Test groups included glass fiber-reinforced polycarbonate, filler-reinforced polycarbonate, and hybrid polymer with inserted metal slot brackets. The static frictional resistance caused by sliding movements with an archwire (stainless steel) in vitro was quantitatively analyzed. Both scanning electron microscope and three-dimensional optical surface profiling were used.
Scanning electron microscope and three-dimensional optical surface profiler revealed that all as-received brackets had irregular slot floor surfaces, and both irregularity and roughness increased after the archwire sliding test. The ceramic brackets in the control group showed significantly lower surface roughness values and higher frictional values during the archwire sliding test compared with the other brackets. The glass or filler-reinforced plastic brackets exhibited significantly higher static frictional values than the metallic slot type brackets (P < .001). The hybrid polymer with inserted metal slot brackets showed relatively lower surface roughness and frictional values compared with the stainless steel control bracket.
Glass or filler-reinforced plastic brackets showed higher frictional resistance than metallic slot-type brackets. A plastic bracket with inserted metal slot may be the best choice among plastic brackets for low frictional resistance and to avoid damage from sliding movements of the archwire.
定量分析三种现代塑料托槽槽底表面粗糙度，并测量体外滑动力学中的静摩擦力。
对照组由不锈钢托槽和单晶陶瓷托槽组成。实验组由三种 0.022 英寸槽、Roth 处方、塑料、上颌右中切牙托槽组成。实验组包括玻璃纤维增强聚碳酸酯、填充增强聚碳酸酯和混合聚合物带插入金属槽托槽。体外使用弓丝（不锈钢）滑动运动引起的静摩擦力进行定量分析。同时使用扫描电子显微镜和三维光学表面轮廓仪。
扫描电子显微镜和三维光学表面轮廓仪显示，所有原始托槽的槽底表面均不规则，且在弓丝滑动试验后，不规则性和粗糙度均增加。与其他托槽相比，对照组中的陶瓷托槽在弓丝滑动试验中表现出明显较低的表面粗糙度值和较高的摩擦力值。玻璃纤维或填充增强塑料托槽的静摩擦力值明显高于金属槽型托槽（P<0.001）。带插入金属槽的混合聚合物托槽与不锈钢对照托槽相比，表现出相对较低的表面粗糙度和摩擦力值。
玻璃纤维或填充增强塑料托槽的摩擦阻力高于金属槽型托槽。带插入金属槽的塑料托槽可能是具有低摩擦阻力和避免弓丝滑动运动损伤的塑料托槽的最佳选择。
