Darabara Myrsini S, Bourithis Lefteris I, Zinelis Spiros, Papadimitriou George D
School of Mining and Metallurgical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., 15780, Athens, Greece.
J Biomed Mater Res B Appl Biomater. 2007 Apr;81(1):126-34. doi: 10.1002/jbm.b.30645.
In orthodontics, a combination of metallic alloys is placed into the oral cavity during medical treatment and thus the corrosion resistance and ionic release of these appliances is of vital importance. The aim of this study is to investigate the elemental composition, microstructure, hardness, corrosion properties, and ionic release of commercially available orthodontic brackets and Copper Ni-Ti archwires. Following the assessment of the elemental composition of the orthodontic wire (Copper Ni-Ti) and the six different brackets (Micro Loc, Equilibrium, OptiMESH(XRT), Gemini, Orthos2, and Rematitan), cyclic polarization curves were obtained for each material to estimate the susceptibility of each alloy to pitting corrosion in 1M lactic acid. Galvanic corrosion between the orthodontic wire and each bracket took place in 1M lactic acid for 28 days at 37 degrees C and then the ionic concentration of Nickel and Chromium was studied. The orthodontic wire is made up from a Ni-Ti alloy with copper additions, while the orthodontic brackets are manufactured by different stainless steel grades or titanium alloys. All tested wires and brackets with the exception of Gemini are not susceptible to pitting corrosion. In galvanic corrosion, following exposure for 28 days, the lowest potential difference (approximately 250 mV) appears for the orthodontic wire Copper Ni-Ti and the bracket made up from pure titanium (Rematitan) or from the stainless steel AISI 316 grade (Micro Loc). Following completion of the galvanic corrosion experiments, measurable quantities of chromium and nickel ions were found in the residual lactic acid solution.
在正畸治疗中，金属合金组合在医疗过程中被置于口腔内，因此这些矫治器的耐腐蚀性和离子释放至关重要。本研究的目的是调查市售正畸托槽和铜镍钛弓丝的元素组成、微观结构、硬度、腐蚀性能及离子释放情况。在评估正畸丝（铜镍钛）和六种不同托槽（Micro Loc、Equilibrium、OptiMESH(XRT)、Gemini、Orthos2和Rematitan）的元素组成后，获取了每种材料的循环极化曲线，以评估每种合金在1M乳酸中发生点蚀的敏感性。正畸丝与每种托槽之间的电偶腐蚀在1M乳酸中于37℃下进行28天，然后研究镍和铬的离子浓度。正畸丝由添加了铜的镍钛合金制成，而正畸托槽则由不同等级的不锈钢或钛合金制造。除Gemini外，所有测试的丝和托槽均不易发生点蚀。在电偶腐蚀中，暴露28天后，正畸丝铜镍钛与由纯钛制成的托槽（Rematitan）或由AISI 316级不锈钢制成的托槽（Micro Loc）之间的电位差最低（约250 mV）。在电偶腐蚀实验完成后，在残留的乳酸溶液中发现了可测量量的铬和镍离子。
