Evaluation of Cytotoxic Effects of Purified Mercury in Human Gingival Fibroblasts-

Background: Since the introduction of amalgam for tooth fillings, there have been concerns that mercury toxicity could pose unacceptable health risks. Methodology: Human gingival fibroblasts (HGF) were exposed to commercially available mercury (CA-Hg) and ayurvedically purified mercury (AP-Hg) at concentrations of 6.25 μM, 12.5 μM, 25 μM and 50 μM. The unexposed HGF cultured in basal media was considered a control. All the samples were cultured for 24 hours and 48 hours, and the cytotoxicity was analyzed by MTT assay. Results: Cell viability between the control and experimental groups varied at 24 hours, however, the results were not statistically significant (p>0.05). At 48 hours, cell viability was higher in the AP-Hg group as compared to the CA-Hg group at the concentration of 6.25 μM, and the difference was statistically significant (p<0.05). The cell proliferation assay results demonstrated a statistically significant difference in the mean optical density values (p<0.05) between CA-Hg and AP-Hg at 12.50 μM, 25 μM, and 50, μM concentrations observed at 24 hours. At 48 hours, a statistically significant difference in the mean OD values (p<0.05) between CA-Hg and AP-Hg at all four concentrations was observed. Conclusion: AP-Hg at a concentration of 6.25 μM demonstrated higher cell viability at 48 hours. Further, the cell proliferation rate was also higher for AP-Hg at all concentrations at 24 and 48 hours. These results indicated a less cytotoxic effect of AP-Hg than CA-Hg in HGF and hence could be employed for dental amalgam preparations.