Dental amalgam mercury exposure in rats

The aim of this study was to measure the distribution of mercury, in tissue s of rats exposed to amalgam over a two months period. Possible interaction of mercury with copper and zinc in organs was also evaluated. Rats were ei ther exposed to mercury from 4 dental amalgams, or fed the diet containing powdered amalgam during two months. Mercury was measured in the kidney, liv er and brain, copper in kidney and brain and zinc in kidney. The results sh owed significantly higher concentrations of mercury in the kidneys and the brains of rats in both exposed groups compared to control. Even after two m onths of exposure to mercury brain mercury concentration in rats with amalg am fillings was 8 times higher than in the control and 2 times higher than in rats exposed to amalgam supplemented diet. The highest mercury concentra tion in the latter group was found in the kidneys and it was 5 times higher than in the control group. We found no significant differences between mer cury levels in exposed and control rat's liver. Exposure to mercury from de ntal amalgams did not alter the concentrations of copper and zinc in the ti ssues. Histopathological analyses of rats tissues did not show any patholog ical changes. These results support previously proposed nose-brain transpor t of mercury released from dental amalgam fillings.