Department of Orthodontics, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Braz Oral Res. 2011 Nov-Dec;25(6):526-30. doi: 10.1590/s1806-83242011005000015.
The aims of this study were to determine and compare frictional resistance obtained by low-friction and conventional elastomeric ligatures in the presence of artificial saliva, and observe whether this variable changed after 21 days. Super Slick® low-friction elastomeric ligatures and conventional ligatures of the brands TP conventional® and Unitek® were placed on standard edgewise maxillary central incisor metal brackets, slot .022" × .028" tying rectangular orthodontic wires .018" × .025". Three experimental groups were arranged according to the type of ligature and a control group in which no wires were used. The friction values obtained between the bracket/wire/ligature set were measured using a Universal Test Machine at a speed of 20 mm/minute, at two experimental time intervals: T0 - immediately after specimen fabrication; and T1 - 21 days after fabrication and immersion in artificial saliva at 37 ºC. Conventional Unitek ligatures and the low-friction ligature (Super Slick) showed the lowest friction values at T0. After 21 days (T1), however, conventional Unitek ligatures presented the lowest value. All groups assessed from T0 to T1 showed a numerical reduction in friction values, suggesting that time, heat and humidity may cause elastic degradation, however this was not verified statistically (P > 0.05).
本研究的目的是确定并比较在人工唾液存在的情况下，低摩擦和传统弹性结扎丝的摩擦阻力，并观察 21 天后该变量是否发生变化。Super Slick®低摩擦弹性结扎丝和传统的 TP 常规结扎丝和 Unitek®结扎丝品牌被放置在标准方丝弓上颌中切牙金属托槽的槽内，槽宽.022"×.028"，结扎矩形正畸丝.018"×.025"。根据结扎丝的类型，将实验分为三组，并设置了一个不使用结扎丝的对照组。使用万能试验机以 20mm/min 的速度测量结扎丝、托槽和弓丝之间的摩擦值，在两个实验时间间隔进行测量：T0 - 标本制作后立即；T1 - 制作后 21 天，并在 37°C 的人工唾液中浸泡。在 T0 时，传统的 Unitek 结扎丝和低摩擦结扎丝（Super Slick）显示出最低的摩擦值。然而，经过 21 天（T1）后，传统的 Unitek 结扎丝显示出最低的摩擦值。从 T0 到 T1 评估的所有组的摩擦值都呈现数值降低，这表明时间、热和湿度可能导致弹性降解，但这并没有通过统计学验证（P＞0.05）。
