To Your Health

Q: A friend recently had the silver fillings in her teeth removed and replaced with ceramic fillings. Although it set her back over $2,000, she says she is feeling better already. Is this something I should do?

A: There are so many considerations to weigh in deciding whether to remove "silver" fillings that it becomes a value judgment for each of us. While there are some advantages to using this material, which is actually an amalgam of mercury and other minerals such as silver, there are also grave concerns, especially when used for filling cavities in children. About half the filling is made up of mercury, a well-known toxic mineral. In the past, the American Dental Association asserted that the mercury remained bound in the filling and was harmless. Now, with more sensitive measuring devices, we know that mercury vapors are released in amounts of about 10 micrograms (mcg) per day for someone with eight fillings, the average number for American adults.

Most adults would probably tolerate this amount of mercury, but children, including unborn children, are more sensitive than adults to mercury toxicity. Since 1994, some countries have restricted its use in children under 7. At present, there is no restriction on mercury fillings in the U.S., but California requires dentists to inform patients of the pros and cons of various options for filling material. Mercury amalgam fillings tend to last longer than the alternatives, which means that poorer patients are more likely to choose this material.

Amalgam fillings are not the only source of mercury in the environment. Large ocean fish (tuna, haddock, swordfish, etc.) are significant sources of mercury. Complicating the picture is the difference in toxicity between elemental mercury (the silvery liquid metal we are familiar with, the form used in amalgam fillings) and organic mercury compounds (the form of mercury in fish). Organic mercury is more toxic than the same amount of elemental mercury, and is more widespread in our environment. Although these fish are an excellent source of much-needed omega-3 essential fatty acids, when they feed in polluted water they carry enough mercury to be dangerous for a pregnant or lactating woman to eat.

Seafood is only one source of organic mercury. Some preservatives found in vaccines, including those given to infants, are organic mercury compounds. Parents should not be forced to choose between protecting a child from infectious disease and imperiling him or her with a toxic mineral.

The chief competitor of mercury is the nutritional trace mineral selenium, which reduces the toxicity of mercury and hinders its absorption. As with mercury, organically bound selenium is preferred. This form, found in foods and some antioxidant preparations, is especially important during pregnancy and lactation.

In addition to toxicity, mercury is an allergen for some people. It may be that when a person experiences immediate health improvement upon removal of mercury amalgam fillings they are reducing their allergen load.

A woman of childbearing age might consider spending the $1,000 to $3,000 necessary to replace her mercury amalgam fillings as an investment in the health of her child. Also, anyone suffering from neurological problems, the most common symptom of mercury toxicity, could justify this procedure. Problems such as seizures, multiple sclerosis, post-polio syndrome, Parkinson's disease, and Alzheimer's disease have been reported to improve after removal of mercury amalgam fillings.