Figure 2.
Determination of minimum exposure time necessary for cell death induction by metal. HGF cells (6 PDL) were incubated for 1, 2, 4, 6, 8 or 24 hours with different concentrations of Ag(NH3)2F (A), AgCl (B), CuCl2 (C) and then resuspended with fresh culture medium, and then further incubated for 23, 22, 20, 18, 16 or 0 hours before MTT assay (Total incubation time=24 hours). Each value represents the mean±S.D of three determinations.