Discoloration Mechanism of Dental Titanium and Titanium Alloys

近年来，钛修复体在牙科临床中得到了广泛的应用。然而，有报道称，钛板被一些假牙清洁剂变色。这项研究调查了原因。通过测量义齿清洁剂的pH值和用EPMA和XPS对变色标本进行表面分析来检测变色。使用碱性范围高的义齿清洁剂观察到严重的变色。变色被认为是由于腐蚀造成的粗糙。变色的程度取决于氧化膜的厚度。研究了白蛋白在含氟溶液中对钛腐蚀行为的影响。钛在含氟溶液中的腐蚀是明显的，在含氟溶液中加入白蛋白可以抑制腐蚀。在含氟溶液中检测钛表面的氟，并确定钛的溶解。将钛浸入含有氟化物和白蛋白的溶液中，无论白蛋白浓度如何，钛都有白蛋白膜。此外，溶液中钛的溶解量比不含白蛋白的溶液少。结果表明，在钝化膜上形成吸附的白蛋白膜，不仅可以保护钛不受氟化物的侵蚀，而且可以抑制氟化钛化合物的溶解。由炎症细胞产生的过氧化氢和氟化物预防剂是钛和钛合金变色的两个可能原因。本研究比较了几种钛合金在过氧化物和氟化物溶液中变色的差异。两种溶液的变色速率不同。Ti-Ni和Ti-Cu合金的色差大于其他含H202的合金。相比之下，这些合金在氟化物溶液中只显示出轻微的变化。这一数据表明，含过氧化物溶液和含氟化物溶液对钛合金的腐蚀速率不同。少

In recent years, titanium prosthetics have been widely used in clinical dentistry. However, there are reports that titanium plates were discolored by some denture cleaner. This study investigated the cause. of discoloration by measuring the pH of denture cleaners and by surface analysis of discolored specimens using EPMA and XPS. Severe discoloration was observed with denture cleaners with a highly alkajine range. Discoloration was regarded as due to roughness caused by corrosion. The degree of discoloration depended on the thickness of the oxide film. The role of albumin on the corrosion behavior of titanium in a solution containing fluoride was elucidated. The corrosion of titanium in a solution containing fluoride was distinct, and that adding albumin to the solution containing fluoride suppressed corrosion. Fluorine was detected on the titanium surface immersed in the solution containing fluoride, and dissolution of the titanium was confirmed. The titanium immersed in a solution co … More ntaining both fluoride and albumin had an albumin film regardless of the albumin concentration. In addition, the amount of dissolved titanium from the titanium immersed in the solution was less than when the solution contained no albumin. It was suggested that the formation of adsorbed albumin films on in the passive film acted to not only protect the titanium from attack by the fluoride but also suppressed dissolution of the titanium-fluoride compounds.Peroxide, which is produced by inflammatory cells, and fluoride prophylactic agents are two possible causes for the discoloration of titanium and titanium alloys. This study compared differences of the discoloration of several titanium alloys caused by peroxide and fluoride solutions. The rates of discoloration were different with the two solutions. The color difference was higher for Ti-Ni and Ti-Cu than for other alloys with H202. In contrast, these alloy showed only a slight change in the fluoride solution. This data implies that the rate of corrosion of titanium alloys is different for solutions containing peroxide than those containing fluoride. Less