[Results of a questionnaire survey of pulmonary complaints in dental technicians: effect of inhalation exposure to heavy metal dusts (cobalt-chromium alloys)].

In the course of their working lifetime, dental technicians are exposed to numerous different dusts, some of which also contain toxic substances (Co-Cr alloys), which are employed in the so-called model casting. In order to establish the influence of the nature of the exposure associated with various dental technical procedures on pulmonary symptoms, 24588 questionnaires were sent to 3415 dental laboratories. The return rate was 21.3%. An evaluation of 4328 questionnaires (with account being taken of the influence of smoking, age and sex), revealed a significant relationship between the duration of work on model casting, and the common symptoms "dry cough", "dyspnoea on exertion" and "productive cough". In agreement with other case reports, the results emphasize the significance of the inhalation of heavy metal dusts in the aetiology of pneumoconiosis in dental technicians.