Xingya Jia et al.: Effects on Cytotoxic and Apoptosis Related Genes Expression Effects of Different Dental Alloys on Cytotoxic and Apoptosis Related Genes Expression in L929 Cells

Cytotoxicity is one of the most important problems in medical metal materials. Effect of different dental alloys on cytotoxic of L929 cells was evaluated by in vitro cytotoxicity-test (MTT method). Metal ion concentration was one of the factors leading to occurrence of cell toxicity. Thus metal ion concentration in cell culture fluid at different intervals of immersion periods were detected by inductively coupled plasma mass spectrometry (ICP-MS). For different medical metals, RT-PCR method was also used to analysis mRNA expression of L929 cells’caspase-3, caspase-8 and caspase-9. The results indicated that MTT test found little optical density (OD) value difference for different alloys at different time points. The cytotoxicity of Cu alloy group was Grade 4 and those of other groups were all Grade 0 after 48 hours culture. The mRNA levels of caspase-8 had no change in all groups. The mRNA levels of caspase-3 and caspase-9 were as follows from low to high: Cu alloy, the negative control and Au alloy, Co-Cr alloy, Ag-Pd alloy,and Ni-Cr alloy after 48 hours’ culture. It is concluded that metal ions of the studied dental alloys may induce cell apoptosis by different degree through mitochondrion pathway. Apoptosis related genes expression of L929 cells was affected by ion concentration in cell culture fluid.