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

牙科材料会在体液中溶解成微量的成分，这会使原发因素带来副作用。因此，澄清溶解组分的溶解动力学和毒性是很重要的。采用电感耦合等离子体发射光谱仪和原子吸收光谱法对溶出物中的金属元素进行定量。从溶解产物的剂量-反应关系研究牙科材料的潜在危害，特别是致敏性和致突变性。钛合金的溶解100 mg粉末合金Ti6Al4V和Ti5A12.5Fe在人唾液中浸泡14周，钛的总溶出量分别为1045和1016 ng。浸泡6周后，100 mg合金中铝的总溶出量分别为165和480 ng。从每种合金中观察到连续微量的溶解，表明可能存在遗传毒性和过敏性。比较NiCl2水育小鼠和皮下植入镍小鼠的血镍含量和过敏性。1)BALB/c小鼠ICR口服镍不能诱导产生抗核抗体。以ICR小鼠17%的频率口服镉诱导ANA。2)口服NiCl2可促进BALB/c小鼠由脂多糖、刀豆蛋白A和PHA诱导的淋巴细胞母细胞形成。皮下植入NiCl2.3)流式细胞仪检测小鼠脾T细胞和B细胞的相对频率与对照组相比无显著差异。4)皮下植入镉的ICR小鼠抑制性T细胞和辅助性T细胞的频率明显低于对照组。

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.