Mercury

The science behind the Amalgam controversy

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It has been well established that mercury from dental amalgams that has been ingested into the stomach is poorly absorbed through the digestive system and is not an important factor in raising the serum mercury level. The vast majority of elemental mercury that shows up in the bloodstream is from mercury vapor which is absorbed through the lungs. The amount of mercury actually absorbed via both routes is so small that it has no practical toxic effect on the human body.

As you read further in this essay, you will see why this is the case.

Low levels of mercury have been with the human race since it first evolved, and our bodies have developed the ability to excrete small amounts easily. Modern studies have shown that the amount of mercury absorbed by a person with a mouth full of amalgam fillings is WELL below the amount necessary to have toxic effects. In fact, numerous studies have shown that the amount of mercury actually released by amalgam fillings is insignificant when compared to the amount consumed in numerous types of food, especially ocean caught fish. Even though fish contains much more absorbable mercury (in the form of methyl mercury which IS well absorbed in the gut), it takes a lot of fish eaten over a long time to bring serum mercury levels into the range where toxic effects are seen. Even populations of Pacific island dwellers which regularly eat a lot of fish and have serum mercury levels in excess of ten times that of the average North American, do not exhibit any ill effects from the mercury constantly in their bloodstream.

NOTE: Google advertisements are placed on web pages by bots which assess content based on key words. This page attracts some ads which link to sites selling "detoxification" medications and services, most of which make many of the claims which I have debunked here. I allow this type of advertisement so readers can see some of the nonsense they sell.

Many population studies have been done which refute the claims of the anti-amalgamists. The following are just six examples:

In one study, dentists with abnormally high concentrations of urinary mercury, attributable to their occupational exposure, showed no evidence of kidney impairment on several key measurements of renal function.
Another study examined claims that dental amalgam interferes with immune function. The researchers found that subjects with dental fillings had the same number of disease fighting white blood cells as people who were amalgam-free.
A Swedish researcher found no differences between amalgam and non-amalgam groups in measures used to assess immune system health, liver and kidney function, and skeletal muscle status.
A Swedish study of 1024 women looked at the prevalence of 30 symptoms often claimed to reflect toxic effects of amalgam, including fatigue, dizziness, irritability, and back pain. Women with more than 20 amalgam fillings were no more likely to complain of these symptoms than women with few or no amalgams.
Another Swedish study examined mercury serum levels in a population of 1462 women in order to correlate their serum mercury levels (from all sources including diet) to the vague symptoms often claimed to be due to mercury intoxication from amalgam. The study correlated serum mercury levels with the incidence of dizziness, eye complaints, hearing defects, headache, general fatigue, sleep disturbances and 25 other symptoms over a period of 25 years. This study found NO correlation between serum levels of mercury and the 31 symptoms studied. (Note: In Sweden, serum mercury levels tend to be much higher than those found in North America or other non-Scandinavian parts of Europe because Scandinavians are more likely to eat large amounts of ocean caught fish which increases serum mercury levels much more than mercury from amalgam fillings.)

I found this study so interesting that I have translated it into plain English so that it could be presented here, as page 7 of this report, to persons without a scientific background. Click HERE to read this study.

A study of 30,000 female dental assistants and the wives of 29,000 dentists, divided into high and low mercury exposure groups found no difference between the two groups in the incidence of miscarriage or of birth defects in their offspring.
Standards set by the US Occupational Safety and Health Administration (OSHA) estimate the mercury-vapor concentration to which even the most sensitive workers can be chronically exposed without suffering adverse effects. Under OSHA guidelines, the maximum safe occupational dose approximates roughly 300 to 500 micrograms of mercury vapor per day. Current estimates predict that people with a moderate to large number of fillings are exposed to 1 to 4 micrograms of mercury vapor per day, barely 1% of the dose considered safe by the US government.

Will removing all your amalgam fillings improve your health?

Beware! The miraculous cures reported by the anti-amalgamists of patients who have had their amalgam fillings removed are of the psychosomatic variety and are NOT permanent! You will NOT solve your health problems by replacing the perfectly good amalgam fillings in your teeth!

On the contrary, you WILL end up needing at least a few (and probably many) root canals and crowns!
The replacement of fillings always entails some stress to the nerve of the tooth, and each time a filling is replaced, there is a distinct chance that the nerve will become inflamed (hot and painful) which will necessitate immediate emergency treatment.
If you cannot afford the cost of a root canal and a crown, then the less expensive alternative is extraction. The cost of keeping your teeth under these circumstances can become prohibitive! The following anecdote is a true story.

An Iowa dentist was barred from practice for five years for advising a woman with multiple sclerosis to have her amalgams removed. Unable to pay $9000 (this was in the mid 1980's when this type of dental work was much less expensive), the woman had all her teeth extracted and replaced with dentures. A month later her illness worsened and she was hospitalized. Her successful lawsuit against the dentist prompted the state dental board to suspend the dentist's license to practice.

Cases like this are ongoing in dentistry, and you can look up the actual litigation for fourteen of them (dates and names of defendants included) by clicking here.

What the government and mainstream organizations have to say about mercury and amalgam

The Food and drug administration (the FDA) has been consistent in its defense of amalgam, however, as of June 2008, it has made a slight change in response to a "white paper" presented by a large array of antiamalgamists. The white paper was rejected by the joint committee panel by a margin of 13-7 because it did not “objectively and clearly present the current state of knowledge about the exposure and health effects related to dental amalgam”. This is a legal way of saying that there is still really no scientific reason to restrict its use. While the paper was rejected by the majority, the minority made "personal recommendations" that amounted to a suggestion to change labeling on amalgam packaging to reflect caution in the use of amalgam in pregnant women and children. This was done on the basis of the "precautionary principle". Once again, scientifically, there is still no reason to hedge about the use of dental amalgam, but LEGALLY, it is always possible to find technicalities which can be used to force changes in public policy, even if those changes are ultimately damaging to the public at large. To see the policies of the governmental organizations, please take the time to review the following US governmental statements on this subject: the US government department of health and human services statement on the safety of dental amalgam.

The safety of dental amalgam has been endorsed by the Arthritis Foundation, The multiple Sclerosis Society, The American dental Association, and the magazine and organization Consumer Reports.

Other references

In order to make more mainstream information available to the general public I offer a separate page as a bibliography of statements and press releases from established scientific organizations. Some of the references have links associated with them. Others are references which can be obtained by writing, phoning or emailing the organization cited and requesting the material. Click here to go to this page.

It is most important to remember that there is no known statistical difference in the health status of persons with amalgam fillings compared to those with no fillings in their teeth!

In fact, metallic (elemental) mercury especially when bound in a solid matrix as it is in dental amalgam, is not especially toxic because it is not well absorbed through the digestive tract, and while the major source of absorbed mercury from amalgam fillings is from mercury vapor, the amount of mercury vapor released from amalgam fillings is relatively small. There is no evidence that the extremely small amounts of mercury that may be released into the mouth from dental fillings presents any danger of mercury poisoning. The mercury that is swallowed and inhaled is easily excreted from the body through the kidneys. Studies show that the average daily intake of mercury from ordinary food and water is between 4 and 15 times the amount that is ingested due to the presence of a mouthful of dental amalgam restorations.

The next page in this essay thoroughly discusses the science behind mercury toxicity.

Next page (What the textbooks say about the safety of dental amalgam)==>

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