Levels of methylmethacrylate, formaldehyde, and asbestos in dental workroom air

The levels of methylmethacrylate and formaldehyde in workroom air of a dental laboratory following finishing and polishing a pour type denture base resin have been measured. The levels of these compounds did not exceed the respective hygienic threshold limit values in the general workroom air or in breathing air close to workpiece. The content of asbestos fibers in breathing air released during dismantling molds from gold casting was measured. During the dismantling procedure the fiber content in the air could exceed threshold limit values by up to about 12 times. However, about 10 min after terminating this process the fiber content had declined to a level below the establish requirements.