Cross-Sectional Study of Health Effects of Methyl Methacrylate Monomer among Dental Laboratory Technicians

• Published in: Journal of Occupational Health 2001-11, Vol.43 (6), p.375-378
• Main Authors: Nishiwaki, Yuji, Saitoh, Takehito, Taklbayashi, Torn, Tanaka, Shigeru, Etoh, Norihito, Eitaki, Yoko, Omaf, Kazuyuki
• Format: Article
• Language: English
• Subjects: Cross‐sectional study; Methyl methacrylate; Nervous system; Pulmonary function; Subjective symptoms
• ISSN: 1341-9145; 1348-9585; 1348-9585
• DOI: 10.1539/joh.43.375

Methyl methacrylate (MMA) monomer is a colorless, volatile liquid with a fruity odor, and has been widely used as an ingredient in acryl sheets, plastics, paints, glues, and etc. It is also used extensively in clinical medicine as a material for prostheses, implants and bone cement in dentistry and orthopedics. Although little is known regarding its biotransformation when absorbed, Mizunuma et al. reported that methanol, a product from in vivo hydrolysis, in urine was useful for biological monitoring of exposure to MMA. The acute toxicity of MMA monomer is considered to be low in experimental animals (oral LD50 in rats: 7, 800 mg/kg, 4-h LC50 in rats: 7, 093 ppm), but many studies have reported that dentists, dental laboratory technicians, orthopedic surgeons, and nurses in the operating room who were occupationally exposed to MMA monomer suffered from allergic dermatitis, asthma and peripheral neuropathy. These studies, however, were case studies or case series, and provided no accurate information on the measured or estimated concentrations of MMA monomer to which their subjects were exposed. Although slower sensory nerve conduction velocities, abnormal respiratory function in subjects exposed to MMA monomer, and hematological changes including lower albumin, glucose and blood urea nitrogen, etc. , in rats were also reported, comprehensive studies of the health effects of MMA monomer were few. To assess the health effects of MMA monomer, we therefore conducted a cross-sectional epidemiological study on dental laboratory technicians who have been occupationally exposed to MMA monomer.