By David A. Albert, D.D.S., M.P.H.
Columbia University College of Dental Medicine

As consumers, we want to know whether the products we use are safe. Products and materials that have been used for many years are often assumed to be safe. This is true in oral health care as well as other areas. Yet questions are being raised about one product that has been used for more than 100 years — amalgam tooth fillings, which contain mercury.

An expert advisory panel of the U.S. Food and Drug Administration (FDA) on September 8 rejected a draft report that reviewed past research and found no problems with the safety of dental amalgam. The experts did not cite any problems either, but they called for additional study on the safety of dental amalgam, particularly for children and developing fetuses.

As its name implies, dental amalgam is an amalgamation of several different metals, notably silver, mercury and copper. The controversy with dental amalgam safety applies to the use of mercury in the filling material. Mercury is a known toxin to nerve tissue, particularly in the developing brains of children. In addition, some individuals are allergic to products that contain mercury.

Scientists have sought to determine if the amount of mercury that is released during insertion of the filling and during chewing are high enough to cause neural problems. Two new studies funded by the National Institutes of Health and published April 19, 2006, in the Journal of the American Medical Association showed higher concentrations of mercury in the urine of children who received amalgam fillings than in children whose teeth were filled with a resin alternate. However, the children with the amalgam fillings did not have a decrease in IQ or memory function when tested, nor did they have a higher rate of kidney problems.

The FDA advisory group's recommendations will raise questions about mercury safety for scientists, the dental profession and the dental consumer. If mercury is known to be dangerous to humans, why do we use it as a component of a dental filling material? Why do so many of us have it in our mouths? If you have dental amalgam fillings in your mouth, should you have them removed and replaced with alternative materials?

Previous well-designed studies have not found adverse health effects from the use of dental amalgam. In 1998, the American Dental Association's Council on Scientific Affairs, after reviewing all relevant studies and literature, reported that "based upon available information, amalgam continues to be a safe and effective restorative material." International groups, the U.S. States Public Health Service and the FDA have come to similar conclusions.

As a consumer, what choice should you make? The answer, in my opinion, is to use caution. For example:

• If you are pregnant, do not have amalgam fillings placed or removed, since removal releases mercury.
• If your child needs a filling, consider alternative materials and discuss the options with your dentist.
• If you have a known allergy to mercury or impaired kidney function, ask your dentist to avoid using amalgam fillings.

New materials such as dental composites and glass ionomer offer the dentist more options for fillings. As a dental consumer, you should ask questions about the type of filling to be used.

Unless appearance is an issue, old amalgams should not be removed if they are in good condition. When fillings are removed, it is possible for a tooth to fracture or break. This can lead to larger fillings, root canal therapy, or extraction of the tooth.

The lifespan of a filling is limited. If an amalgam has been present more than 10 years, it should be evaluated for replacement; however, if it is intact, and providing good function, it should be left in place.

It is important to note that the use of dental amalgams has been decreasing because of a decrease in the number of dental cavities and the use of other dental materials. This trend probably will continue, even as research continues on the safety of amalgam.

David A. Albert, D.D.S., M.P.H., is an associate professor and assistant director of Community Health at the Columbia University College of Dental Medicine. He also holds an appointment in the Joseph Mailman School of Public Health at Columbia University. He is the principal investigator of a Robert Wood Johnson Foundation Addressing Tobacco in Managed Care project conducted with Aetna Dental. He maintains a practice within the ambulatory care network of the Columbia DentCare program in the community of Washington Heights/Inwood in Northern Manhattan.