da Silveira Ramiro Estacia, Elias Carlos Nelson, do Amaral Flávia Lucisano Botelho
Faculdade São Leopoldo Mandic, Instituto de Pesquisas São Leopoldo Mandic, Campinas, Brazil.
Laboratório de Biomateriais, Instituto Militar de Engenharia, Rio de Janeiro, Brazil.
Microsc Res Tech. 2022 May;85(5):1884-1890. doi: 10.1002/jemt.24049. Epub 2022 Jan 8.
Several mechanical and biological factors may change the orthodontic wire frictional resistance (FR). Titanium dioxide (TiO ) and silica dioxide (SiO ) nanoparticle (NP) coatings may be used to improve the characteristics of materials, reducing FR between archwire and bracket. This in vitro study aimed to evaluate the FR of orthodontic wires with and without coating in both dry and wet environments and measure the surface roughness (SR). One hundred and eighty segments of rectangular Cr-Ni orthodontic wires (Morelli Co, Brazil) were divided into three groups according to the NP coating applied: TiO group; SiO group; and control group. The SR parameters were measured in an optical profilometer, the surface morphology was analyzed with scanning electron microscopy (SEM), and FR was performed in a universal testing machine in dry and wet environments (n = 30). The statistical analysis was performed using the Generalized Estimated Equations model with a Bonferroni post-test (α = 0.05). It was observed that SiO NP coating decreased FR significantly when compared to the TiO and control groups, in both environments (p < .001). The SiO and TiO groups presented statistically lower SR than the control group and were similar to each other (p < .001). The SiO group presented the lower depth of Valley parameter than the TiO group (p < .001). The SEM showed that the TiO coating had the most heterogeneous surface morphology than the SiO and control groups. The orthodontic wires with NP coating modified the FR and morphology. The SiO coating reduced FR in both dry and wet environments and decreased SR. Titanium dioxide (TiO ) and silica dioxide (SiO ) nanoparticles coatings may be used to reduce frictional resistance (FR) between archwire and bracket as well as to improve surface morphology. The SiO coating reduced FR in both dry and wet environments and decreased the SR of Cr-Ni orthodontic wire. The TiO coating promoted the most heterogeneous surface morphology of Cr-Ni orthodontic wire.
多种机械和生物因素可能会改变正畸弓丝的摩擦阻力（FR）。二氧化钛（TiO₂）和二氧化硅（SiO₂）纳米颗粒（NP）涂层可用于改善材料特性，降低弓丝与托槽之间的FR。本体外研究旨在评估在干燥和潮湿环境下有涂层和无涂层正畸弓丝的FR，并测量表面粗糙度（SR）。将180段矩形Cr-Ni正畸弓丝（巴西Morelli公司）根据所应用的NP涂层分为三组：TiO₂组；SiO₂组；以及对照组。在光学轮廓仪中测量SR参数，用扫描电子显微镜（SEM）分析表面形态，并在万能试验机中在干燥和潮湿环境下进行FR测试（n = 30）。使用广义估计方程模型和Bonferroni事后检验（α = 0.05）进行统计分析。观察到，在两种环境下，与TiO₂组和对照组相比，SiO₂ NP涂层均显著降低了FR（p < 0.001）。SiO₂组和TiO₂组的SR在统计学上低于对照组，且彼此相似（p < 0.001）。SiO₂组的谷底深度参数低于TiO₂组（p < 0.001）。SEM显示，TiO₂涂层的表面形态比SiO₂组和对照组的更不均匀。带有NP涂层的正畸弓丝改变了FR和形态。SiO₂涂层在干燥和潮湿环境下均降低了FR并减小了SR。二氧化钛（TiO₂）和二氧化硅（SiO₂）纳米颗粒涂层可用于降低弓丝与托槽之间的摩擦阻力（FR）以及改善表面形态。SiO₂涂层在干燥和潮湿环境下均降低了FR并减小了Cr-Ni正畸弓丝的SR。TiO₂涂层使Cr-Ni正畸弓丝的表面形态最不均匀。
