Rongo Roberto, Ametrano Gianluca, Gloria Antonio, Spagnuolo Gianrico, Galeotti Angela, Paduano Sergio, Valletta Rosa, D'Antò Vincenzo
a PhD Student, Department of Neuroscience, Reproductive Science and Oral Science, University of Naples "Federico II,", Naples, Italy.
Angle Orthod. 2014 Jul;84(4):665-72. doi: 10.2319/081213-593.1. Epub 2013 Dec 5.
To evaluate the effects of intraoral aging on surface properties of esthetic and conventional nickel-titanium (NiTi) archwires.
Five NiTi wires were considered for this study (Sentalloy, Sentalloy High Aesthetic, Superelastic Titanium Memory Wire, Esthetic Superelastic Titanium Memory Wire, and EverWhite). For each type of wire, four samples were analyzed as received and after 1 month of clinical use by an atomic force microscope (AFM) and a scanning electronic microscope (SEM). To evaluate sliding resistance, two stainless steel plates with three metallic or three monocrystalline brackets, bonded in passive configuration, were manufactured; four as-received and retrieved samples for every wire were pulled five times at 5 mm/min for 1 minute by means of an Instron 5566, recording the greatest friction value (N). Data were analyzed by one-way analysis of variance and by Student's t-test.
After clinical use, surface roughness increased considerably. The SEM images showed homogeneity for the as-received control wires; however, after clinical use esthetic wires exhibited a heterogeneous surface with craters and bumps. The lowest levels of friction were observed with the as-received Superelastic Titanium Memory Wire on metallic brackets. When tested on ceramic brackets, all the wires exhibited an increase in friction (t-test; P < .05). Furthermore, all the wires, except Sentalloy, showed a statistically significant increase in friction between the as-received and retrieved groups (t-test; P < .05).
Clinical use of the orthodontic wires increases their surface roughness and the level of friction.
评估口腔内老化对美观型和传统镍钛（NiTi）弓丝表面性能的影响。
本研究采用了五种镍钛丝（Sentalloy、Sentalloy高美观型、超弹性钛记忆丝、美观型超弹性钛记忆丝和EverWhite）。对于每种丝材，通过原子力显微镜（AFM）和扫描电子显微镜（SEM）对四个刚收到时的样本以及临床使用1个月后的样本进行分析。为评估滑动阻力，制作了两块带有三个金属或三个单晶托槽的不锈钢板，托槽以被动方式粘结；每种丝材的四个刚收到时的样本和回收样本通过Instron 5566以5毫米/分钟的速度拉伸5次，每次1分钟，记录最大摩擦值（牛顿）。数据采用单因素方差分析和学生t检验进行分析。
临床使用后，表面粗糙度显著增加。SEM图像显示刚收到时的对照丝材表面均匀；然而，临床使用后，美观型丝材表面呈现出有坑洼和凸起的不均匀状态。刚收到时的超弹性钛记忆丝在金属托槽上的摩擦水平最低。在陶瓷托槽上测试时，所有丝材的摩擦力均增加（t检验；P < 0.05）。此外，除Sentalloy外，所有丝材在刚收到时的样本和回收样本之间的摩擦力均有统计学显著增加（t检验；P < 0.05）。
正畸弓丝的临床使用会增加其表面粗糙度和摩擦水平。
