In 1989, the National Research Council (NRC) published "Improving Risk Communication," a report spawned by an earlier study on risk assessment in the Federal government. In the report, the NRC defines "risk management" as "a term used to describe processes surrounding choices about risky alternatives." Risk management, according to the NRC, is the endpoint response following assessment of the risks and benefits of specific hazards.1
One potential hazard that has captured substantial attention is the use of dental amalgam to treat dental caries Some scientists and patient advocacy groups have voiced concern about the potential dangers arising from mercury vapor from amalgam restorations. Media stories have further heightened consumer concern. In 1991, an American Dental Association survey of 1,000 American adults revealed that nearly half believed that health problems could develop from dental amalgam.2
Also in 1991, the National Institutes of Health (NIH) and the Food and Drug Administration (FDA) separately convened panels of experts to evaluate the current state of knowledge regarding amalgam-related hazards and render professional opinions about the safety of this product. In both cases, the experts agreed that current research information does not demonstrate a causal relationship between dental amalgam and a human health detriment.3 In addition, the U.S. Public Health Service, at the direction of the Assistant Secretary for Health, brought together risk assessment and benefits independent judgment about the degree of health risk, if any, posed by amalgam use. They, too, determined that current research data do not demonstrate a health hazard for the vast majority of individuals exposed to mercury vapor at levels commonly encountered from dental amalgam. However, these groups have recommended more research before the possibility of amalgam-caused risks, as well as possible risks that may result from the use of alternative materials, can be dismissed.
At a February 1992 symposium on the toxicity of mercury vapor from dental amalgam, held under the auspices of the Society of Toxicology, experts agreed that more remains to be learned about the effects of chronic, low-level mercury exposure associated with amalgam. Attendees agreed on the need for the development of new and sensitive biomarkers of exposure and toxicity. They also called for more research in the areas of neurologic, reproductive, developmental, and renal effects, and the mechanisms that underlie them. Finally, the participants encouraged investigation into autoimmune-mediated renal injury induced by mercury.4
Also last year, the Swedish Medical Research Council held a scientific conference on the biological consequences of mercury released from dental amalgam. A June 1992 Council report (see Appendix VIII) on the conference concluded that "mercury released from dental amalgam does not, according to available data, contribute to systemic disease or systemic toxicological effects" or "give[s] rise to teratological effects."
In response to growing concern about amalgam safety, which predated many of these events, the Assistant Secretary for Health—acting in his capacity as Chairman of the PHS Committee to Coordinate Environmental Health and Related Programs—directed that a risk management plan be developed. In broad concept, the plan was to address research needs, taking into account research studies now underway to quantify potential health risks from mercury in dental amalgam. The plan was also to outline possible educational messages and programs for putting amalgam risks into perspective and to identify options for increased regulatory oversight of this product.
This report responds to that charge. This report is not intended to serve as the authoritative source on dental amalgam safety, but rather as a planning tool to assist policy-makers in deciding on appropriate risk management actions.
1Improving Risk Communication, Committee on Risk Perception and Communication / National Research Council. National Academy Press, Washington, D.C. - 1989. pg. 37.
2ADA News. April 8,1991. pg.3.
3"Effects and Side-Effects of Dental Restorative Materials." An NIH Technology Assessment Conference, National Institute of Dental Research, Bethesda, Maryland, August 26-28, 1991. In Advances in Dental Research, Volume 6, 1992.
4 Goering, P.L., et al. Symposium Overview. Toxicity Assessment of Mercury Vapor from Dental Amalgams. Fundamental and Applied Toxicology.