The Great Dental Amalgam Debate

March 2001
Originally published in HealthWise Magazine

The debate about the safety of silver/mercury fillings continues and it is the patients that are caught in the middle.

Ever since amalgam was introduced in the United States in the 1830’s, there has been debate about the safety of this common filling material. Surprisingly, dental patients have been relatively uninformed about what is being placed in their mouths.

First, an important fact about “silver” fillings. In reality, they could just as easily be called “mercury” fillings, because they contain as much as 50–55% mercury. It seems that even though most people realize that dental amalgams contain some mercury, few know that it is in fact the largest component. While the American Dental Association (ADA) and the FDA continue to claim that the mercury is in a safe, bound form, opponents of amalgam argue otherwise.

It is interesting that the government, despite standing behind the safety of amalgam, has set strict standards for its disposal. Because dental amalgam meets the EPA criteria of hazardous waste, it is illegal to dispose of it in the garbage. Yet, it can legally be placed in a patient’s mouth. The FDA, which has banned the use of mercury in every other product, has “grand-fathered” the use of mercury for dental amalgam.

It is these kinds of discrepancies that have fueled the fire of the amalgam opponents. However, many dentist opposed to amalgam are afraid to speak out, because the powerful ADA’s code of ethics has made the removal of serviceable mercury amalgam restorations an issue of ethical conduct. In the ADA’s point of view, it is ethical for a dentist to place mercury amalgam restorations in a patient and claim their safety. However, according to the ADA’s code of ethics, a dentist who acknowledges that mercury amalgam restorations are toxic and recommends their removal has acted unethically (“…the removal of amalgam restorations from the non-allergic patient for the alleged purpose of removing toxic substances from the body when such treatment is performed solely at the recommendation of the dentist is improper and unethical….” ADA Resolution 42H-1986. Transaction 1986:536). On the basis of the ADA’s code of ethics, state dental boards have taken disciplinary action against mercury-free dentists who have practiced their profession in accordance with current scientific knowledge and their conscience. The disciplinary action has ranged from restrictions placed on their practice to the loss of license.

It will be interesting to see what the future will bring. Christopher Bomba, a lawyer experienced in toxic product litigation predicts – “In the coming decade, as evidence of the danger of mercury amalgams accumulates, we will see an explosion of litigation similar to that associated with asbestos, silicone implants and tobacco cigarettes. Eventually, perhaps in ten to twenty years, mercury amalgams will be banned in the United States.”

Not far fetched since we are already seeing this happening in some European countries. And, in this country, back in 1994, a proposition passed in California that required a warning in dental offices using mercury amalgam. It stated that “the people of the state of California have determined that the use of mercury in dental amalgam causes birth defects and other health problems.” The proposition also requires that permission must be obtained from a patient before placing hazardous material in the mouth. (The new law was contested by the ADA and California Dental Association, and is tied up in Federal Court). Similar “informed consent” legislation was also proposed in Minnesota.

Even all debate about toxicity aside, dental amalgam is not the best filling material available today. The mercury in amalgam expands and contract with temperature changes (just like mercury in a thermometer) which may cause the tooth to break. And, because the amalgam does not adhere to the tooth, bacteria and fluids can seep under the filling. Maybe the greatest drawback from the patient’s perspective, is the fact that they are not tooth-colored.

Today’s dentist has a wonderful arsenal of tooth-colored, bonded filling materials available. When properly placed, these materials look just like the original tooth and in the process strengthen and protect the tooth.

All of which makes you wonder why we are even having an amalgam debate.