THE DENTISTS EXPOSURE TO ELEMENTAL MERCURY-VAPOR DURING CLINICAL-WORKWITH AMALGAM

Continuous measurements of mercury vapor in the breathing zone of the dentist were made under ordinary clinical conditions. Fifty old amalga m fillings were removed and replaced by new ones. The mercury vapor me asurements were performed by means of atomic absorption spectrophotome try. On the basis of the type of suction device used, the measurements were divided into seven groups, each of which consisted of a series o f measurements. During the cutting, filling, and polishing operations the mean mercury vapor levels in the breathing zone of the dentist wer e in the range of 1-2 mu g Hg m(-3) air when proper mercury hygiene me asures were taken, This is far below the currently valid threshold lim it value (30 mu g Hg m(-3) air) in Sweden. The saliva extractor and th e dental mirror-evacuator did not influence the mercury vapor levels w hen used together with the high-volume evacuator. However, when only a saliva extractor was used, the cutting of amalgam filings caused high ly fluctuating mercury vapor levels, which were 2-15 times higher than the threshold limit value.