Dental restorative materials from a work environmental perspective

Abstract: The main occupational health hazard for dental personnel is muscle-skeletal problem, followed by symptoms caused by exposure to chemicals. Clinical dental work includes exposure to a number of products like soap, detergents, disinfectants, amalgam, mono- and oligomers, catalysts, inhibitors, solvents and adhesives. Some are chemically very active. The aims of this thesis have been to survey the occurrence of symptoms from skin, eyes and respiratory tract among dental personnel working in general dental practice. Further, to analyse the use of personnel protective devises and, if needed develop ergonomic recommendations for safe use. An additional aim was to evaluate the irritation potential to skin and eyes of some different polymer products using HET-CAM technique. The thesis is based on three questionnaire studies, one observation study and one biological testing. Results showed that information to dental personnel on classification and handling of amalgam and amalgam contaminated waste products is far from sufficient. Further one fifth of both dentists and chair assistants experienced a number of hypersensitive reactions when handling dental polymer products. Dentists, working in general dental practice, reported a significantly higher prevalence of allergic conjunctivitis, atopic dermatitis, and hand dermatitis, than chair assistants and referents. A majority of dental personnel used protective devices (except dental safety glasses) but obviously the protection is not sufficient. Hand dermatitis was significantly more prevalent in some counties, based on the national study (7384 respondents). Based on theoretical and practical information collected in the observation study, four ergonomic checkpoints were developed. Each checkpoint indicated an action, and additionally "why", "how", "some hints" and "remember" with short explanation. All liquids of the different type of polymer materials tested were strongly irritants in the biological testing, but none of the extracts from cured, or freshly mixed non-cured products. This study indicates that patients are exposed to materials with lower irritation potential than dental personnel who handle the non-cured products manually are. This highlights the importance of learning how to handle dental polymer materials, especially the liquids, in a safe manner.