Effects of occupational environmental controls and work management on chromosomal damage in dental technicians in Japan

Dental technicians use various materials, particularly metal alloys and monomers and polymers based on methylmethacrylate. Environmental hygiene issues surrounding the work of dental technicians have been recognized. Despite the need for observance of occupational environmental controls and work management, compliance among dental laboratories appears to be low. We evaluated the relationship between genotoxic effects in dental technicians and occupational environmental controls and work management. We used cytokinesis-blocked micronuclei (CB-MN) frequencies in peripheral lymphocytes and metal levels in scalp hair. We also assessed nutritional factors related to anti-genotoxic effects using a self-administered brief diet history questionnaire. Study subjects were 54 male dental technicians and 38 male clerical workers. The parameters on the micronuclei (MN) frequency in dental technicians and clerical workers were analyzed by forward stepwise multiple regression analyses. Age (P < 0.01, β = 0.561), occupation as a dental technician (P < 0.01, β = 0.636) and aluminum levels in scalp hair (P < 0.05, β = 0.213) were risk factors that significantly increased MN frequency. The significant parameters on the MN frequency in dental technicians were observance of hand-washing as work management (P < 0.01, β = -0.304), work period (P < 0.01, β = 0.509), germanium levels in scalp hair (P < 0.01, β = -0.314) and workplace (P < 0.05, β = 0.235). To avoid genotoxic effects, observance of occupational environmental controls and work management is necessary for dental technicians.