Studies on the potential hazards of trace amounts of dental materials dissolution

牙科材料在体液中溶解成微量成分，这将使主要因素带来副作用。因此，澄清溶解动力学和溶解组分的毒性是很重要的。用ICP和原子吸收分光光度法测定溶出物中的金属元素。从溶解产物的剂量-反应关系出发，探讨了口腔材料的潜在危害，特别是致敏性和致突变性。Ti6Al4V和Ti5A12.5Fe粉末合金100mg在人唾液中浸泡14周，溶出的总钛量分别为1045和1016 ng。浸泡6周后，100 mg合金中铝的溶出量分别为165 ng和480 ng。从各合金中观察到连续痕量的溶出，提示可能具有遗传毒性和致敏性。镍和镉的致敏性比较了nicl_2 -水饲养小鼠和皮下镍植入小鼠的血镍含量和致敏性。1)口服镍未诱导BALB/c小鼠ICR产生抗核抗体（ANA）。ICR小鼠以17%的频率口服镉诱导ANA。2)口服NiCl_2可促进LPS、Con-A和PHA对BALB/c小鼠淋巴细胞的形成。皮下注入nicl_2后，Con-A细胞的形成增加。2.3)流式细胞术检测的小鼠脾T细胞和B细胞的相对频率在对照组和镍、镉组之间无显著差异。4)皮下镉植入ICR小鼠的抑制性T细胞和辅助性T细胞频率较对照组明显降低。

Dental materials are dissolved in the body fluid into trace amounts of components, which will make primary factors to bring side effects. Thus, it is important to clarify the dissolution kinetics and the toxicity of dissolved components. The metal elements in dissolution were quantitated by ICP and atomic absorption spectrophotometry. The potential hazards, particularly allergenicity and mutagenicity, of dental materials were investigated from the dose-response relationship on the dissolved products.1. Dissolution of titanium alloyThe total amounts of titanium dissolved from 100 mg of powdered alloys, Ti6Al4V and Ti5A12.5Fe, were 1045 and 1016 ng, respectively during 14 weeks immersion in human saliva. The total amounts of aluminum dissolved from 100 mg of the alloys were 165 and 480 ng, respectively during 6 weeks immersion. The continuous trace amounts of dissolution was observed from each alloy, suggesting the possibility of genotoxicity and allergenicity.2. Allergenicity of nickel and cadmiumThe quantitation of the blood nickel and allergenicity was compared between mice of NiCl_2-water breeding and mice of subcutaneous nickel implantation.1) The anti-nucleus antibody (ANA) was not induced by oral administration of nickel into ICR of BALB/c mice. The ANA was induced by oral administration of cadmium with a frequency of 17% of ICR mice.2) The lymphocyte blast formation by LPS, Con-A and PHA was enhanced by oral administration of NiCl_2 into BALB/c mice. The blast formation by Con-A was increased by subcutaneous implantation of NiCl_2.3) The relative frequency of mice spleen T cell versus B cell measured by flowcytometry was not different between the control and the nickel- or cadmium-administered mice.4) The frequency of suppressor T cell and helper T cell was significantly decreased in the ICR mice of subcutaneous cadmium-implantation, as compared to the control.