Occupational health risks in dentistry - musculoskeletal disorders and neuropathy in relation to exposure to physical workload, vibrations and mercury

Abstract: The aim of the thesis was to focus on the occupational health risks in dentistry with emphasis on musculoskeletal disorders in the neck and upper limbs and neuropathy in the hands, in relation to exposure to physical workload, vibration and mercury. An increased high frequency of long-lasting and wide-spread musculoskeletal symptoms in the neck and shoulder regions (58-75% during the past 12 months) was found in dentists and dental hygienists compared to different referent groups; furthermore, wrist/hand (46-59%) and hip (19-27%) disorders as well in female dentists and dental hygienists. This was also verified by a clinical examination of female dental personnel. There was an obvious risk that the disorders lead to a selection out of work. In addition, sensorineural disturbances were found among the vibration exposed groups. Subjective ratings of vibration exposure duration was found to be unreliable. However, it was not possible to prove that there was any relationship between musculoskeletal symptoms or sensorineural disturbances and the mercury and selenium status, or even smoking habits and overweight. The mercury levels were higher among the dental personnel compared to the referents, who were not occupationally exposed, but were still low compared to risk levels. The amount of own amalgam fillings was strongly correlated to the mercury levels in urine, blood and plasma. Exposure measurements of physical workload, in field studies of female dentists, showed a high static and median muscular load with lack of pauses in the shoulder and fore-arm muscles, forward tilted extreme positions of the head and awkward positions in the wrists. Subjects with disorders tended to work with lower muscular load and less extreme positions than those without disorders.