Effect of precious alloys on cell viability (in vitro)

Abstract

Extracts were obtained by gyrating cylindrical specimens of typeIII gold, gold-silver-palladium, and silver-indium alloy on a disk-shaped specimen of the same alloy at 240 rpm for 7 and 14 days. The amount of Au, Pd, Ag, Cu, In and Zn released was measured using inductively coupled plasma spectrometry. The cell viability of extracts and filtrates was evaluated by neutral red and 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assays. The six metals were detected in the extracts. Cu was the most easily dissolved. Ag and Pd were not detected in the filtrates. Cell viability of the extracts showed a significant decrease in silver-indium alloy, compared to typeIII gold and gold-silver-palladium alloys. Cell viability increased after filtration in every extract. These results indicate that dynamic extraction might be useful in evaluating the dissolution and cytotoxicity of metallic biomaterials that mimic stress-bearing restorations.