The present questionnaire survey of side effects of biomaterials in prosthodontics had a response rate of 64%. There were occupational health problems associated with a variety of dental materials, especially acrylic resins, eugenol-containing materials, and elastomer impression materials. Most reactions were mild to moderate dematoses of the fingers or hands, but one prosthodontist had to cease practice due to a severe allergic reaction to acrylic resin materials. Of the respondents, 8% had experienced reactions to latex gloves. Nondermatologic reactions seemed to be transient, affecting the eyes, respiratory pathways, or occasionally causing generalized symptoms. These reactions were mainly attributed to vapors from acrylic resin monomers or cyanoacrylates. Adverse reactions in patients, tentatively estimated to be one out of 300, were observed by 40% of the prosthodontists, mostly as intraoral reactions. Acrylic resins, eugenol-containing cements, base metal alloys, mercury, gold, polyether/epimine based materials, and tissue conditioners were cited as causes. Skin contact with the dentists' latex gloves elicited extraoral reactions in some patients.