Institute of Medicine, Chung Shan Medical University, Department of Dentistry, Chung Shan Medical University Hospital, Taichung, Taiwan.
Angle Orthod. 2010 May;80(3):547-53. doi: 10.2319/042909-235.1.
To test the hypothesis that different nickel-titanium (NiTi) archwires may have dissimilar corrosion resistance in a fluoride-containing oral environment.
Linear polarization test, a fast electrochemical technique, was used to evaluate the corrosion resistance, in terms of polarization resistance (R(p)), of four different commercial NiTi archwires in artificial saliva (pH 6.5) with various NaF concentrations (0%, 0.01%, 0.1%, 0.25%, and 0.5%). Two-way analysis of variance was used to analyze R(p) with the factors of archwire manufacturer and NaF concentration. Surface characterizations of archwires were analyzed using scanning electron microscopy, atomic force microscopy, and x-ray photoelectron spectroscopy.
Both archwire manufacturer and NaF concentration had a significant influence on R(p) of NiTi archwires. Different surface topography was present on the test NiTi archwires that contained the similar surface chemical structure (TiO(2) and trace NiO). The surface topography did not correspond to the difference in corrosion resistance of the NiTi archwires. Increasing the NaF concentration in artificial saliva resulted in a decrease in R(p), or corrosion resistance, of all test NiTi archwires. The NiTi archwires severely corroded and showed similar corrosion resistance in 0.5% NaF-containing environment.
Different NiTi archwires had dissimilar corrosion resistance in acidic fluoride-containing artificial saliva, which did not correspond to the variation in the surface topography of the archwires. The presence of fluoride in artificial saliva was detrimental to the corrosion resistance of the test NiTi archwires, especially at a 0.5% NaF concentration.
检验不同镍钛（NiTi）弓丝在含氟口腔环境中可能具有不同耐腐蚀性的假设。
线性极化测试，一种快速电化学技术，用于评估四种不同商业 NiTi 弓丝在 pH 6.5 的人工唾液中不同 NaF 浓度（0%、0.01%、0.1%、0.25%和 0.5%）下的耐腐蚀性，以极化电阻（R(p)）表示。采用双因素方差分析方法分析 R(p)，因素为弓丝制造商和 NaF 浓度。使用扫描电子显微镜、原子力显微镜和 X 射线光电子能谱分析弓丝的表面特性。
弓丝制造商和 NaF 浓度对 NiTi 弓丝的 R(p)均有显著影响。测试 NiTi 弓丝的表面形貌存在差异，但具有相似的表面化学结构（TiO(2)和痕量 NiO）。表面形貌与 NiTi 弓丝耐腐蚀性的差异不对应。人工唾液中 NaF 浓度的增加导致所有测试 NiTi 弓丝的 R(p)，即耐腐蚀性降低。NiTi 弓丝在含 0.5% NaF 的环境中严重腐蚀，表现出相似的耐腐蚀性。
不同的 NiTi 弓丝在酸性含氟人工唾液中的耐腐蚀性不同，这与弓丝表面形貌的变化不一致。人工唾液中氟化物的存在对测试 NiTi 弓丝的耐腐蚀性有害，尤其是在 0.5% NaF 浓度下。
