Safety of Dental Fillings
Many people are questioning the safety of mercury amalgam dental fillings. These are the silver colored fillings, sometimes called silver amalgam by dentists. Only about 30% is silver, the rest is mainly mercury with smaller amounts of copper, zinc, and tin.
from the book "How to Save Your Teeth"
Mercury has an effect on the fetal nervous system, even at
levels far below that considered to be toxic in adults. Background
levels of mercury in mothers correlate with incidence of fetal
birth defects and still births.
Reuhl and Chang, 1979; Clarkson et al., 1981; Marsh et al, 1980; Tejning 1968; W.D. Kuntz, R.M. Pitkin, A.W. Bostrum, and M.S. Hughes, The American Journal of Obstetrics and Gynecology, 143, no. 4:440-443, 1982.
Mercury fillings can contribute to a higher level of mercury
in the blood and can affect the functioning of the heart, change
the vascular response to norepinephrine and potassium chloride
and block the entry of calcium ions into the cytoplasm.
Abraham et al., "The Effect of Dental Amalgam Restorations on Mercury Blood Levels," Journal of Dental Research, 63, no. 1:71-73, 1984; Kuntz et al., "Maternal and Cord Blood Background Mercury Levels: A Longitudinal Surveillance", American Journal of Obstetrics and Gynecology, 143, no. 4:440-443, 1982; Joselow et al., 1972; Mantyla and Wright, 1976: Trakhtenberg, 1968; Oka et al., 1979.
The United Kingdom Department of Health advises pregnant women against the installation of new amalgam fillings.
Sweden has banned the use of mercury (amalgam) fillings entirely.
Health Canada is considering limiting the allowable number of amalgam surfaces to two for children and eight for adults.
Several amalgam filling manufacturers warn about the dangers associated with mercury use in their "material safety data" and "directions for use". They say that amalgam fillings should not be used in or near teeth with crowns or fillings containing other metals. Amalgam is not recommended for pregnant women, children under 6, and people with kidney disease. They state that symptoms of psychiatric illness are often caused by very low exposure to mercury vapours which may be released during dental work, chewing, drinking hot liquids, etc.