The various therapies encompassed by biological dentistry all share a single basic premise: They are founded on the idea that the teeth can affect the general health of the body, and vice versa.

For example, the theory for which biological dentistry is best known asserts that the mercury in amalgam fillings can make you sick, leading to recurrent health problems, such as neurologic disorders, chronic fatigue, and arthritis. To remedy these ailments, proponents say, you need only have all your amalgam fillings removed and replaced with less toxic alternatives, such as non-metallic quarts based fillings or porcelain inlays.

Many dentists and oral surgeons can and often do remove amalgam fillings at their patients request. However, before you embark on what could become a very expensive and uncomfortable series of dental procedures, you should consider the fact that both the American Dental Association and the National Institutes of Health have specifically rejected the amalgam theory. There is no scientific evidence, they say, of any detrimental effects from amalgam.

Of course, the so-called amalgam problem is not the only reason that people seek out biological dentists. The various unconventional treatments seek to cure a broad spectrum of ailments ranging from headache to heart disease through operations on the teeth and mouth. Some people adopt these therapies as 'natural' or 'non-toxic' alternatives to mainstream treatment. However, none of them have been proven effective in scientific tests.