Studies on cytotoxic effect of nickel ions on three cultured fibroblasts

Cytotoxicity of Ni ions on three fibroblasts such as L929, Balb/3T3 clone A 31 and MC3T3-E1 were examined by cell count (CC) and Neutral Red assay (NR) . Three cells were incubated for 6 days in 1 ml DME medium containing Ni io ns which ranged from 0 to 2 mM/l. The results clarified that Ni ions had do se-dependent cytotoxicity. L929 possessed the largest TC50 values (the amou nt of Ni ion that caused 50% cell death or 50% cell viability) of 0.12 mM/l (CC) and 0.32 mM/l (NR), and Balb/3T3 clone A31 had the least values of 0. 05 mM/l (CC) and 0.09 mM/l (NR), whilst MC3T3-E1 had the intermediate value s of 0.08 mM/l (CC) and 0.15 mM/l (NR). The dissolution of Ni ions from Ni- containing metallic restorations must be lower than these concentration lev els so that body tissues might not be severely damaged. (C) 2001 Kluwer Aca demic Publishers.