"Filling" You in on the Facts
There’s been much publicity recently about dental amalgam. This is nothing new. In fact, there have been questions raised about amalgam fillings ever since they were first introduced in the 1820s. At issue is the mercury contained in these fillings, and specifically, if this contributes to illness.
Therefore, the Massachusetts Dental Society (MDS), as your resource for dental health information in the Commonwealth, believes it’s important for the public to know the facts about amalgam. In addition, the MDS emphasizes that the type of filling materials used is a matter of choice and that patients should discuss their options with their dentist because each situation is different.
What is amalgam?
For more than 150 years, billions of dental amalgam fillings have been used to restore decayed teeth. All dental amalgam, commonly referred to as silver fillings, contains various metals. These include silver, copper, and tin, as well as mercury, which is needed in order to chemically bind these other metals together to form a hard, stable, restorative material.
Why is amalgam used?
Dental amalgam is used for a number of reasons, including its durability, longevity, and ability to withstand the intense pressures of chewing. Because of these attributes, it is often the material of choice in restoring posterior teeth. It’s also a very cost-effective option for restorative materials. Many in the dental profession believe other materials either don’t work as well or are more expensive. Gold, for example, is a very effective material, but it is more costly and not tooth-colored. Tooth-colored, composite resins may not be suitable for restoring large chewing surfaces. Porcelains may provide a natural appearance but are more costly.
If mercury is a toxic material, why isn’t the mercury contained in amalgam also considered to be toxic?
Some concerns have been raised about amalgam because of its mercury content. The concern is intuitive but unfounded. Although mercury by itself is classified as a toxic material, the mercury in amalgam chemically combines with other metals to render it stable and therefore safe for use in accepted dental applications. Mercury also can be found in food, water, and air, so there is always a very low level of mercury present in the human body.
Under the pressures of vigorous chewing and grinding, very small amounts of mercury vapor may be released. But the fact is that the daily dosage of mercury from nondental sources exceeds the minuscule amount released from amalgam fillings. Also, the human body has a mechanism to eliminate mercury through urine and feces over time.
What is the most recent research on amalgam?
Studies conducted by a wide range of groups, including the American Dental Association (ADA), the National Institutes of Health (NIH), the Centers for Disease Control and Prevention (CDC), and the Food and Drug Administration (FDA), have all concluded that amalgam is safe, with no link found to any medical disorder. The following are statements issued by some of these organizations:
- “There is no sound evidence of any harm for millions of Americans who have these fillings and no persuasive reason to believe that avoiding amalgams or having existing amalgams replaced will have a beneficial effect on health.”
—U.S. Public Health Service
- “No valid scientific evidence has ever shown that amalgams cause harm to patients with dental restorations.”
—The Food and Drug Administration’s Center for Devices and Radiological Health
- “The small amount of mercury released from amalgam restorations, especially during placement and removal, has not been shown to cause any other adverse health effects.”
—The World Health Organization, The European Commission, the National Board of Health and Welfare in Sweden, the New Zealand Ministry of Health, Health Canada, and the Province of Quebec have all reached similar conclusions.
Is it possible to have an allergic reaction to amalgam?
A very small number of people are allergic to amalgam fillings. In fact, according to the American Dental Association, fewer than 100 cases have ever been reported.
In these rare instances, mercury or other components of amalgam can trigger symptoms similar to those of a typical skin allergy. If a patient is truly allergic or has a family history of allergies to metals, then another restorative material should be used.
Can a dentist advise a patient to have amalgam removed for safety reasons?
The Food and Drug Administration has concluded that amalgam fillings causes no demonstrated clinical harm to patients and that removing amalgam will not prevent adverse health effects or reverse the course of existing diseases. The National Multiple Sclerosis Society, for example, has found no evidence that multiple sclerosis is related to amalgam fillings. (In the case of MS, a patient’s condition may improve or symptoms may even suddenly disappear for a period of time for no known reason.)
Are people ever cured from illnesses after amalgam fillings are removed?
The American Dental Association’s Council on Ethics, Bylaws, and Judicial Affairs has stated that based on scientific data, the removal of amalgam restorations from the nonallergic patient for the sole purpose of removing this substance from the body (when such treatment is performed at the recommendation of the dentist) is improper and unethical. The same principle of veracity applies to the dentist’s recommendation concerning the removal of any other dental restorative material. Replacing dental amalgam for aesthetic purposes has its own risks, and the patient and dentist should discuss these risks and benefits before replacing any serviceable amalgam restorations.
The Massachusetts Dental Society has also taken steps to address the issue of amalgam as it relates to the environment. In January 2001, the MDS signed a Memorandum of Understanding with the state Department of Environmental Protection relating to the safe handling and disposal of waste amalgam from dental offices. The MDS was the first state dental association in the country to sign a formal agreement with a state environmental agency.