According to the EPA, dentists in the United States use approximately 34 tons of mercury per year.
Silver fillings aren’t primarily silver and never have been. Since they were developed in France in the early 1800’s, their main ingredient has always been mercury. Today’s amalgam typically consists of about 50% elemental mercury alloyed with varying amounts of silver, tin, copper and zinc. Amalgam releases mercury vapor continuously throughout the time it is in your mouth. The amount of vapor released is increased by chewing (when the fillings are located on the occlusal surfaces), by tooth brushing and by consuming hot liquids. Approximately 80% of the mercury vapor will be absorbed into your body where it will deposit itself in your nervous system, kidneys, liver and thyroid gland.
There has been ongoing controversy over the health risks of dental amalgam internationally. The WHO estimates that amalgam fillings are the greatest source of daily mercury exposure in those who have them, greater than all other sources combined, and ranging from 3-27mcg per day. A study done in 1998, estimated that, “on average, each ten-surface increase in amalgam exposure is associated with an increase of 1mcg/L mercury in urine.” (Kingman et al.) Dental associations, generally, have strongly fought the notion that there are negative health effects from mercury amalgam, but studies are ongoing. It is well-established now that about 23% of patients with mercury amalgam will show systemic allergy to inorganic mercury. Mercury amalgam can also be the cause of lichenoid lesions in the mouth. Patients with poor kidney function should not receive amalgams because of their impaired ability to excrete mercury.
The National Health and Nutrition Examination Survey 3 (NHANES) for the years 1988-1994 found a significant positive correlation between number of amalgams and the following disorders: infectious and parasitic diseases, cancer, thyroid disorders, mental disorders, diseases of the nervous system and sense organs and other disorders of the central nervous system (MS, other demyelinating disorders of the CNS, other paralytic syndromes, epilepsy, migraine, cataplexy, narcolepsy and cerebral cysts). The dental associations argue that correlation does not prove causation. Anti-amalgam activists argue that the precautionary principle should apply. Partly on this basis, Norway and Sweden have banned the use of mercury amalgam altogether.
The greatest health risk from mercury amalgam is to young children and to fetuses and infants whose mothers had amalgams while pregnant or nursing. Mercury is well-established as a neurodevelopmental toxin. Mercury from dental amalgam can pass through the placenta to the fetus. Studies have shown that the levels of mercury in fetal liver, kidney and brain tissues were proportionate to the number of amalgam fillings in the mother. Mercury is also known to pass into the breast milk of mothers with amalgams.
The reasons not to allow amalgam to be placed in your mouth go well beyond the potential effects on your health, however. When bodies are cremated, the high temperatures vaporize the mercury in the deceased’s amalgams. Cremation is increasing in popularity vs. burial and the current population of seniors has a relatively high number of mercury amalgams. In 2002, the Colorado Department of Public Health and Environment estimated that 110 pounds of mercury were released into the air by crematoria in that state alone. Canadian estimates from 2004 indicate that between 1.5% and 5% of that country’s total mercury emissions are from crematoria. Four states have considered regulating mercury emissions but the cost is quite prohibitive due to the small size of most of the furnaces, particularly retrofitting existing ones. Eight European countries require emissions control on new or large crematoria. Requiring morticians to pull teeth from bodies has been a political non-starter. The bottom line is that it makes more sense to reduce the use of mercury amalgams in the first place.
Another reason to avoid mercury amalgam is to reduce the occupational exposure of your dentists and hygienists. A number of studies have shown negative health effects in these professions due to their daily handling and cleaning of amalgam. These effects include neurological symptoms in the extremities, poor memory and concentration, fatigue and insomnia. Dentists and hygienists consistently have elevated mercury levels compared to control populations. For example, a study of Turkish dentists found that they had urinary mercury concentrations about three times those of controls (Karahalil et al. 2005). As a patient, you should also be aware that between 6% and 16% of dental offices exceed the air mercury standards established by OSHA.
A third reason to consider not using mercury amalgams is that dental wastewater is the largest contributor to the mercury load in our sewage systems. The Association of Metropolitan Sewerage Agencies estimates that about 36% of mercury entering publicly owned treatment plants is discharged from dental offices. Several states including New Hampshire, New York and Oregon, have introduced laws requiring dental offices to install amalgam separators on their wastewater discharges to prevent this contamination, which eventually ends up in our lakes and rivers. The AMSA also reports that domestic wastewater (i.e. from homes) can contain significant amounts of mercury and estimates that 80% of it comes from human wastes from individuals with amalgam fillings.
Given the potential health risks and the environmental impacts, 19 members of congress organized by Congresswoman Diane Watson and Congressman Dan Burton, had asked that the FDA be more stringent in its labeling and disclosure requirements for amalgam. Unfortunately, as of July 28th, 2009, the FDA has classified dental amalgam as a Class II or “moderate risk” medical device. They have stated that the published evidence does not show a health risk to adults or children over the age of 6. This leaves the most “at risk” groups uninformed which is unacceptable. We at SafeMinds see no sense in allowing a neurotoxin to be installed 3 inches from your brain when there are other alternatives readily available. We encourage you to choose mercury-free dentistry.
Please note: There is risk in removing dental amalgams, since amalgams must be removed via drilling which heats the mercury and increases the amount of mercury vapors. It is very important that amalgams are removed in a manner that avoids excessive exposure to mercury vapors to the patient and dentist. See http://www.iaomt.org/ for information on “Safe Removal of Amalgam Fillings” and a list of mercury-free dentists. SafeMinds does not endorse removal of mercury fillings in anyone without significant symptoms consistent with mercury toxicity.
Related video: The effect of mercury on growth of neurons
