OCCUPATIONAL SKIN DISEASES IN DENTAL LABORATORY TECHNICIANS .1. CLINICAL PICTURE AND CAUSATIVE FACTORS

In Germany, occupational skin disease (OSD) in dental technicians (DT) has been steadily rising in recent years and causing considerable cos ts for medical care and rehabilitation. Our objective in this study wa s to: (i) examine affected workers; (ii) perform patch tests to identi fy causative agents; (iii) develop strategies of prevention. 7 dental laboratories were inspected as to materials used, working habits, safe ty regulations, etc. A computer data base was developed for products ( trade name, active ingredient, additives, etc.). A questionnaire regar ding development of OSD was sent out to 1132 dental technicians (45 qu estions). 55 DT with suspected OSD were examined and patch tested with the standard series, an extensive series of methacrylates, and own ma terials. Working conditions, and knowledge of potential hazards, varie d greatly in the laboratories visited. The safety data sheets of worki ng materials were of little use and required supplementation by the co mputer data base, which provided rapid access to allergological inform ation (e.g., type of acrylate, concentration). In the questionnaire (1 73 answers), 36% reported skin lesions attributed to work and 1/3 susp ected plastic materials as their primary cause. Among the 55 DT examin ed, allergic contact dermatitis was diagnosed in 63.6% and irritant co ntact dermatitis in 23.6%. Most of the allergens identified (74%) were found in plastic materials (methyl methacrylate (MMA), 9 patients (16 %); 2-hydroxyethyl methacrylate (2-HEMA), 18 patients (33%); ethyleneg lycol dimethacrylate (EGDMA), 15 patients (27%)). In 16 patients, mult iple sensitizations to various methacrylates were found. The fingertip s were primarily involved in allergic contact dermatitis (93%), wherea s in irritant contact dermatitis, the dorsa of the fingers (especially of the dominant hand) were affected (80%). 9 patients also showed les ions on the face, neck and forearms. The main irritant factors include d wet work, contact with plaster, mechanical friction and thermal chan ges. Based on experience with DT, various preventive measures have bee n tried and found to be effective (reduction of skin contact, 4H Glove s, etc.). In conclusion, better knowledge of OSD in dental laboratorie s (in physicians, DT and their employers) would lead to a reduced rate of new cases. (C) Munksgaard, 1996.