NO EVIDENCE OF RENAL TOXICITY FROM AMALGAM FILLINGS

Dental amalgam continuously releases mercury. Studies of sheep [Boyd e t al., Am. J. Physiol. 261 (Regulatory Integrative Comp. Physiol. 30): R1010-R1014, 1991] showed decreased renal function after placement of amalgam fillings. In this study, renal function was investigated in 1 0 healthy volunteers before and after amalgam removal. The subjects ha d an average of 18 tooth surfaces filled with amalgam, which was remov ed during one dental session. One week before sind sixty days after re moval, the glomerular filtration rate (GFR) was determined by Cr-51-ED TA clearance technique. Blood and urine samples were collected for ana lysis of mercury, creatinine, beta(2)-microglobulin, N-acetyl-beta-glu cosaminidase (NAG), and albumin 1 wk before and 1, 2, and 60 days afte r amalgam removal. The plasma mercury concentration increased signific antly 1 day after removal. Sixty days later, significantly lower mercu ry levels were found in blood, plasma, and urine. The GFR values were similar before and after mercury exposure (mean 94 and 94 ml/min per 1 .73 m(2), respectively). No detectable effects occurred on excretion o f NAG, beta(2)-microglobulin, or albumin. It is concluded that no sign s of renal toxicity could be found in conjunction with mercury release d from amalgam fillings.