"Mercury Use in Dental Amalgam" summarizes the use of mercury in dental amalgam. The information in the Fact Sheet is based on data submitted to the state members of the Interstate Mercury Education and Reduction Clearinghouse (IMERC)¹ including Connecticut, Louisiana, Maine, Massachusetts, New Hampshire, New York, Rhode Island, and Vermont. The data is available online through the IMERC Mercury-Added Products Database.²

A number of important caveats must be considered when reviewing the data summarized in this Fact Sheet:

• The information may not represent the entire universe of dental amalgam sold in the U.S. The IMERC-member states continuously receive new information from mercury-added product manufacturers, and the data presented in this Fact Sheet may underestimate the total amount of mercury sold in this product category.
• The information summarizes mercury use in dental amalgam sold nationwide since 2001. It does not include mercury amalgam sold prior to January 1, 2001 or exported outside of the U.S.
• Reported data includes only mercury that is used in the product, and does not include mercury emitted during mining, manufacturing, or other points in the products' life cycle.

Dental amalgam, used in restorative work for filling teeth, is an alloy that contains silver, tin, copper, other metallic elements, and mercury, which typically makes up about 50 percent of the amalgam. Historically, dentists mixed amalgam on-site using bulk liquid mercury and metal powders, but today dental amalgam is purchased in pre-dosed amalgam capsules that come in different sizes. The mercury content of each capsule can vary from 100 to 1,000 milligrams of mercury.

Table 1 presents the total amount of mercury sold in dental amalgam in 2001 and 2004. Five dental amalgam manufacturers have submitted Mercury-added Product Notification Forms to IMERC-member states.

Reported use of mercury in dental amalgam sold in the U.S. in 2001 was approximately 30.8 tons, decreasing slightly to 30.4 tons in 2004, or by about 1 percent. Increased consumer awareness of mercury use in fillings may drive future declines in mercury amalgam use; however, non-mercury fillings are more expensive, which can affect the preferences of patients for dental restorative materials.

Over the past five years, many states have introduced best management practices (BMPs) for dental amalgam waste so that dental offices capture and recycle this waste. These BMPs include requirements for installing amalgam separators, properly managing solid waste with amalgam, and amalgam recycling. These practices can prevent mercury from dental amalgam entering wastewater, wastewater sludge, and solid waste and, therefore, help to reduce the environmental impact of dental amalgam wastes and discharges.

As of August 2008, the U.S. Food and Drug Administration (FDA) is evaluating its regulatory oversight of mercury dental amalgam. The Agency has reopened the comment period on a proposed rule originally published in 2002 seeking to provide reasonable assurance of the safety and effectiveness of dental amalgam.