Evaluation of corrosion resistance of free-machining titanium alloy

现代牙科CAD/CAM技术要求钛合金具有良好的切削加工性和耐腐蚀性。最近，易切削钛合金通过分散硫化物或稀土元素生产。本研究通过电化学性能和细胞毒性评价牙科用易切削钛合金的耐腐蚀性和细胞毒性。本实验中使用纯钛、Ti-3Al-2 V合金和两种易切削钛合金（DT 2F、DAT 52 F：大同钢）。极化电阻和动电位极化曲线使用电化学装置（PARC恒电位仪，型号273，软件M352 C）和储存在35℃恒温室中的腐蚀电池测量。将用纯氮气脱气的0.9%NaCl和1.0%乳酸溶液用作测试溶液。SEM观察检查电化学测量后点蚀的存在。 ...更多信息 将尿液成纤维细胞、5，000个细胞/ml Eagle MEM+10% FBS接种在24孔（16 mm直径）中的金属（13 mm直径× 1 mm厚）上，并在37℃、5% CO2下孵育。结果表明，易切削钛合金的自然电极电位和极化电阻均低于纯钛和Ti-3Al-2 V合金。动电位极化曲线表明，所有钛合金的钝化电位均在0.0V左右，而易切削钛合金的钝化电流密度明显高于易切削钛合金。所有合金的过钝化电位几乎相同。在0.9%NaCl溶液中对易切削钛合金表面进行腐蚀试验，发现其表面存在凹坑。据此推测，易切削钛合金的耐腐蚀性能不如纯钛和Ti-3Al-2 V合金，在3 d时增殖细胞数差异不显著，而在7 d时细胞增殖率低于纯钛（P<0.05）。少

Current dental CAD/CAM process demands the development of titanium alloy which exhibits excellent machinability and corrosion resistance. Recently, free-machining titanium alloy produced by dispersion of a sulfide or rare earth elements. This study evaluated the corrosion resistance and cytotoxicity of free-machining titanium alloy for dental application through the electrochemical properties and. cell proliferation test.Pure titanium, Ti-3Al-2V alloy and two free-machining titanium alloys (DT2F, DAT52F : Daido steel) were used in this experiment. Polarization resistance and the potentiodynamic polarization profile were measured using an electrochemical device (PARC Potentiostat, Model 273 with soft-ware M352C) and a corrosion cell stored in a thermostatic chamber at 35℃. A 0.9% NaCl and a 1.0% lactic acid solution deaerated with pure nitrogen gas were used as a test solution. SEM observation examined presence of pitting corrosion following the electroche mical measurement.Using L929 m … More urine fibroblast, 5,000 cells/ml of Eagle's MEM+10% FBS were seeded on the metal (13mm diameter×1mm thick) in 24 well (16mm diameter) and incubated at 37℃ in 5% CO2. After 3 and 7days, the number of cells was counted using cell counterThe natural electrode potential and the polarization resistance of free-machining titanium alloys were lower than those of titanium and Ti-3Al-2V alloy. From the potentiodynamic polarization behavior, all titanium alloys showed same passive potential (around 0.0 V vs SCE), However free-machining titanium alloys showed remarkable high passive current density. The transpassive potential was nearly the same for all alloys. The pits were recognized on the surface of free-machining titanium alloy which was tested in the 0.9%NaCl solution. Accordingly, it was estimated that the corrosion resistance of free-machining titanium alloy was inferior to pure titanium and Ti-3Al-2V alloy.The proliferated cell number was not significantly different at 3 days, while the cell proliferation rate of free-machining titanium alloys was lower than that of pure Ti at 7 days (P<0.05). Less