Exposure to airborne methacrylates and natural rubber latex allergens in dental clinics

The exposure of dental personnel to airborne methacrylates and natural rubber latex (NRL) allergens was studied during placing of composite resin restorations in six dental clinics in Finland. Both area and personal sampling were performed, and special attention was paid to measurement of short-term emissions from the patient's mouth. Methacrylates were collected onto thermal desorption tubes filled with Tenax TA and NRL allergens onto membrane filters. The methacrylate samples were thermally desorbed and analysed by gas chromatography with mass selective detection. The NRL allergen concentrations were determined by the allergen-specific IgE-ELISA-inhibition method. The median concentration of 2-hydroxyethylmethacrylate (2-HEMA) was 0.004 mg m(-3) close to the dental nurse's work-desk and 0.003 mg m(-3) in the breathing zone of the nurse with a maximum concentration of 0.033 mg m(-3). Above the patient's mouth the concentration of 2-HEMA was about 0.01 mg m(-3) during both working stages, i.e., during application of adhesive and composite resins and during finishing and polishing of the fillings. Maximum concentrations of 3-5 times higher than median concentrations were also measured. Triethyleneglycol dimethacrylate was released into the air mainly during the removal of old composite resin restorations (0.05 mg m(-3)) and only to a minor extent during finishing and polishing procedures. The median concentration of the NRL allergen was 0.12 au m(-3) (au = arbitrary unit) with a maximum concentration of 1.1 au m(-3). The results show that, except for short-term emissions from the patient's mouth, the exposure of dental personnel to methacrylates and NRL allergens is very low. Measures to reduce exposure are discussed, as the airborne concentrations of methacrylates should be kept as low as possible in order to reduce the risk of hypersensitivity.