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Analysis of U.S. Representative Diane Watson's Proposed
"Mercury in Dental Filling Disclosure and Prohibition Act"

Robert S. Baratz, MD, DDS, PhD

On November 5, 2001, U.S. Representative Diane Watson (D-CA) issued a statement outlining her reasons for introducing a bill to outlaw the use of amalgam fillings. Amalgam use has been supported by the American Dental Association; the U.S. Public Health Service; the vast majority of dentists; the National Council Against Health Fraud; and Consumers Union, publisher of Consumer Reports magazine. Here is a segment-by-segment analysis of the fallacies involved in the wording of the bill.


To prohibit after 2006 the introduction into interstate commerce of mercury alloy intended for use as a dental amalgam, and for other purposes.

The FDA regulates medical devices sold in interstate commerce. Dental amalgam as such -- which the bill refers to as "mercury alloy" -- is not sold in interstate commerce. Amalgam is made from two components, mercury metal and an alloy of silver, copper, tin and other metals. They are sold as separate medical devices and are approved separately by the FDA. Mercury alloy is not sold to dentists, only mercury metal. An alloy of mercury is created when amalgam is made in a dentist's office. Thus, this bill would not apply to dental amalgam.

The American scientific community, on which the FDA depends in part for its advice in the FDA regulatory processes, bases its opinions on the scientific process of discovery, validated by experimental evidence. The purpose of this bill seems to mandate the adoption of illegitimate facts upon the scientific community. It would be a grave and dangerous precedent for that to occur. The review and regulation of medical devices and their components should be based on objective scientific fact, not political whimsy.

Be it enacted by the Senate and House of Representatives of the United States of America in Congress assembled,


This Act may be cited as the ''Mercury in Dental Filling Disclosure and Prohibition Act''


The Congress finds as follows:

(1) Mercury is an acute neurotoxin.

Reality: Although some forms of mercury are toxic, the mercury in amalgam is chemically bound and poses no health risk.

(2) A dental amalgam, commonly referred to as a "silver filling" consists of 43 to 54 percent mercury.

Reality: This statement is misleading because it makes no distinction between the metallic mercury used to make the amalgam and the alloyed mercury, which has different physical and chemical properties.

(3) Each such dental amalgam contains about the same amount of mercury as is present in a mercury thermometer, about 1/2 to 3/4 of a gram.

Reality: This statement is highly misleading. The chemical form of mercury in thermometers differs from that in amalgam. Moreover, swallowing the contents of a broken thermometer poses little risk because metallic mercury is poorly absorbed by the body and simply exits through the intestines.

(4) The mercury in a dental amalgam continually emits poisonous vapors.

Reality: This statement is false. Very sensitive instruments can detect billionths of a gram of mercury vapor in the mouth of a person with amalgam fillings. However, there is no credible evidence that this material is actually absorbed, or, if it is absorbed, in what form. The minuscule amount of mercury the body might absorb from amalgams is far below the level known to exert any adverse health effect and is similar to what is normally found in water and food [1-6].

(5) Mercury does not change its physical properties when mixed with other metals in an amalgam.

Reality: This statement is absurd. Since metallic mercury is liquid and the amalgam in dental fillings is solid, common sense should indicate that a chemical change has taken place.

(6) Consumers may be deceived by the use of the term "silver" to describe a dental amalgam, which contains substantially more mercury than silver.

Reality: Silver refers to the color of the filling, which is composed of alloys of silver and other metals. There has never been any attempt to deceive consumers regarding the composition of dental amalgam. When referring to alloys, the word amalgam is actually defined as "made with mercury."

(7) According to some manufacturer warnings, Health Canada, the Agency for Toxic Substances and Disease Registry of the Public Health Service, the Institute of Medicine of the National Science Foundation, and certain scientific studies, children, including those still in the womb, are at particular risk for exposure to mercury contained in dental amalgam.

Reality: There is no exposure, because dental amalgam contains very little if any mercury. No identified health risk has been established for dental amalgam when used in patients.

(8) According to the Agency for Toxic Substances and Disease Registry, the mercury from amalgam goes through the placenta of pregnant women and through the breast milk of lactating women, giving rise to health risks to an unborn child or a baby.

Reality: This statement refers to a portion of ATSDR's Toxicological Profile for Mercury, which states that young children might be more sensitive to mercury than adults but adds that "exposure to very small amounts of mercury, such as that from dental amalgam fillings, does not necessarily pose a health risk." [7] ATSDR's toxicological profiles, developed in response to the Superfund Amendments and Reauthorization Act of 1986 (Public law 99-499), are prepared by outside contractors and peer reviewers who summarize the scientific literature. The profiles do not represent ATSDR policy, and the mercury profile should not be interpreted as a warning to avoid amalgam.

(9) Both the Institute of Medicine and the American Pediatric Medical Association advise that no product containing mercury should be given to children or pregnant women, and the use of mercury in any product being put into the body is opposed by many governmental entities and health groups, such as the Institute of Medicine, the American Public Health Association, the California Medical Association, and Health Care Without Harm.

Reality: The statements made by the Institute of Medicine, American Pediatric Association, American Public Health Association, California Medical Association were not intended to apply to dental amalgam. Health Care Without Harm an alliance of groups primarily concerned with environmental issues and has no special expertise or standing in any debate about amalgam fillings. Searching its Web site, I found documents expressing concern about reducing the potential hazards of environmental mercury but nothing calling for the elimination of dental amalgam.

(10) Consumers and parents have a right to know, in advance, the risks of placing a product containing a substantial amount of mercury in their mouths or the mouths of their children.

Reality: Since dental amalgam poses no known risks, there is no reason to engage consumers and parents in irrelevant discussion.

(11) Alternatives to mercury-based dental fillings exist, but many publicly and privately financed health plans do not allow consumers to choose alternatives to mercury amalgam.

Reality: No insurance company or government program forces any dentist to use any material. Amalgam is often the best choice because it is durable and relatively inexpensive [8]. It would make no sense for Congress to force insurance companies to pay for materials that are less durable and more expensive.


(a) PROHIBITION. Section 501 of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 351) is amended by adding at the end the following:
(j) Effective January 1, 2007, if it is a mercury alloy intended for use as a dental amalgam.

Reality: As noted above, this statement does not apply to dental materials currently regulated by the FDA.

(b) TRANSITIONAL PROVISION. For purposes of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 301 et seq.), effective July 1, 2002, and subject to subsection (a), a device that is a mercury alloy intended for use as a dental amalgam shall be considered to be misbranded, unless it bears a label that provides as follows: "Dental amalgam contains approximately 50 percent mercury, an acute neurotoxin. Such product should not be administered to children less than 18 years of age, pregnant women, or lactating women. Such product should not be administered to any consumer without a warning that the product contains mercury, which is an acute neurotoxin, and therefore poses health risks."

Reality: As noted above, no such risks exist.

For Further Information


  1. Mackert JR. Dental amalgam and mercury. Journal of the American Dental Association 122:54-61, 1991.
  2. The mercury in your mouth. Consumer Reports 56:316-319, 1991.
  3. Olsson S, Bergman M. Daily dose calculations from measurements of intra-oral mercury vapor. Journal of Dental Research 71:414-423, 1992.
  4. Mackert JR. Factors affecting estimation of dental amalgam exposure from measurements of mercury vapor in levels in intraoral and expired air. Journal of Dental Research 66:1175-1180, 1987.
  5. Mackert JR Jr, Berglund A. Mercury exposure from dental amalgam fillings: absorbed dose and the potential for adverse health effects. Critical Review of Oral Biology and Medicine 8:410-436, 1997.
  6. Berglund A. Molin M. Mercury vapor release from dental amalgam in patients with symptoms allegedly caused by amalgam fillings. European Journal of Oral Science 104:56-63, 1996.
  7. Mercury. ATSDR Public Health Statement, March 1999.
  8. Dental Board of California. Dental materials fact sheet, adopted Oct 17, 2001.


Dr. Baratz is president of the National Council Against Health Fraud. He has extensive training and practical experience in internal medicine, emergency medicine, oral medicine, dentistry, material science, and research methodology. In addition to practicing medicine and dentistry, he serves as a medical and dental consultant to many state licensing boards, federal agencies, insurance companies, and the legal profession.

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This article was posted on November 13, 2001.