Trace metals in dental practitioners: a three-year study

Concern regarding the hazard of mercury to the health of dentists has been widely expressed. Three groups of patients have been followed for three years to evaluate the effect of dental practice on mercury levels in the serum of dentists. At the beginning of the study and again three years later, only dental practitioners with at least twenty years of active practice had significantly higher levels of mercury in their sera. In no patient, however, was a serum mercury level higher than 5 mu g/dl obtained and this value is far below that which usually precipitates clinical symptoms of mercury toxicity. Thus, the occupational hazard of mercury to dentists may be overstated. Copper and zinc are also used in dental practice and the serum levels of these metals were investigated. None of the three groups had mean serum values that were beyond the normal ranges expected. There may be some differences related to age, diet or, possibly, occupation, but further investigation with a larger control group is needed.