A Critique of the International Academy of
Oral Medicine and Toxicology's Anti-Amalgam Video

Stephen Barrett, M.D.

The International Academy of Oral Medicine and Toxicology (IAOMT) was founded in 1984. Its activities are centered around its concepts of biological dentistry [1]. Nearly all of its members are dentists. In March 2015, its online membership directory listed about 700 dentists, most of them in the United States. Its primary target is dental amalgam.

IAOMT asserts that amalgam fillings are poisonous and pose a serious threat to the health of everyone who has one [2]. This message is promoted on the Internet in a video, "Smoking Teeth = Poison Gas," which was produced and directed by David Kennedy, D.D.S. and funded by a grant from the Preventive Dental Health Association, a group he founded that also opposes water fluoridation. The original video was 40 minutes long, but an 8½-minute version has been more widely distributed. Both versions highlight a demonstration claiming to show mercury vapor outgassing in large amounts from a tooth that has been warmed or rubbed with a pencil eraser. The video states that the mercury release demonstration was performed by Roger Eichman, D.D.S. at the IAOMT Oxford England Symposium 2000.

Here is a transcript of the shorter version with my factual responses in red boldface type.

Narrator: All mercury and silver fillings leak substantial amounts of mercury constantly. The amount increases with any kind of stimulation, and, as a result, mercury from fillings produces the majority of human exposure to mercury.

Not true. Dental amalgam is not the major source of exposure in our environment [3]. In addition, well designed studies have shown that amalgams add very little to the daily dose of mercury one gets from breathing air, drinking water, and eating food. The minor increase in exposure, which is considered trivial and without risk, is well worth the benefit of having strong, inexpensive, lasting dental restorations.

Narrator: The International Academy of Oral Medicine and Toxicology is extremely concerned about the anecdotal claims of safety by manufacturers and dental trade associations. They're at variance with the published, peer-reviewed scientific evidence to the contrary.

The claims made by manufacturers and professional organizations are not anecdotal. They are based on many years of peer-reviewed, published scientific research. The vast majority of dentists and dental scientists support amalgam use.

Narrator: The precautionary principle requires action once the possibility of harm exists. It does not require proof beyond a shadow of the doubt that, in the case of heavy metal and xenobiotic exposure, is both nearly impossible and unnecessary in our opinion.

The precautionary principle of risk management actually states that if an action has a suspected risk of causing harm to the public or to the environment, in the absence of scientific consensus that the action or policy is not harmful, the burden of proof falls on those taking an action [4]. The scientific consensus is that amalgam fillings are safe.

Narrator: What you're seeing is mercury vapor coming off a 25-year-old silver amalgam filling in an extracted tooth. The background is a phosphorescent screen. The mercury vapor absorbs the fluorescent light, and you can see it as a shadow on the screen. [The video depicts what the narrator describes as "mercury coming off a filling that was dipped in water that's the same temperature as the human body" followed by "a filling that was rubbed with a pencil eraser for just a few seconds. Like going to the hygienist and having them clean your teeth." The image to the right shows a tooth being held during one of these segments.]

Narrator: These are not small amounts of mercury. If you can see it, it's more than 1,000 times higher than the Environmental Protection Agency will allow for the air that we breathe.


Narrator: What about the last time you went to the dentist and they drilled on your tooth? Here is the mercury vapor every time you raise the temperature to 110 degrees with hot coffee, or warm water, or even chewed on it? Mercury comes off fillings every time you stimulate them, and that stimulation causes the mercury to continue to leak out of the fillings for an hour and a half at a minimum. Some people grind their teeth, some people chew gum.

Experts who have watched the video believe that what appears to be "smoke" is actually water vapor [5]. They have also pointed out that if the smoke were actually mercury vapor, it would fall rather than rise because mercury vapor is heavier than air. It would be interesting to know what would have happened if the tooth had been compared to one without an amalgam filling and the teeth were examined both wet and dry, but the "experimenter" chose not to do this. Regardless, the narrator's conclusion flies in the face of well-established facts about the amount of mercury released by amalgam. If the amount released were as substantial as the video suggests, the filling would have deteriorated and fallen apart long before it was 25 years old. The proper way to determine mercury exposure is to measure blood and urine levels, which indicate how much has been absorbed by the body. The best estimate of the typical amount of mercury released from amalgams is 1 to 2 micrograms of mercury per day for people with more than eight restorations [6], which is well below the exposure limits recommended by government agencies.

Narrator: The dentist might send an old gold crown to the dental lab to be welded. How about the dental personnel? They're not being given informed consent. Back in 1985, the International Academy of Oral Medicine and Toxicology set up to determine the amount of mercury that was coming off fillings. And here's the graph showing substantial quantities of mercury were measured coming off films. And then we estimated the total dose.

The graph shown in the video was originally published in a 1985 article by Canadians Murray Vimy, D.M.D., and Fritz Lorscheider, Ph.D., who worked at the University of Calgary [7]. Their numbers are not credible, however, because they came from tests with a Jerome mercury detector, an industrial safety device that is used to measure the concentration of mercury in room air and has no legitimate dental use. Mercury in the air is potentially toxic if inhaled. Under normal conditions, very little gets inhaled because any traces of mercury vapor produced during chewing or brushing will be diluted by the air within the mouth or bound by saliva and either exhaled, spit out, or harmlessly swallowed. When a Jerome device is used, however, air is collected near the tooth before it has a chance to disperse or dissolve within in the mouth and the resultant measurements are artificially high [8]. Respected experts have concluded that Vimy and Lorscheider grossly overestimated the mercury vapor inhalation [9,10].

And then we began animal experiments and put radioactive fillings in the sheep. Mercury accumulated in the jaw, stomach, liver, and kidney of the sheep in just 30 days. Substantial quantities of mercury spread from the fillings to every organ in that sheep's body. This should be of concern one for everyone. Then we measured that sheep's kidneys dropped in their ability by 60% to clear insulin—an indication of kidney malfunction. Whole body imaging of monkeys found exactly the same thing. Proponents of amalgam fillings claim that sheep chew too much. Well what's the problem of monkeys? They had mercury in their jaw, kidneys, liver, intestine and heart. And further research found dystrophic bacteria that were antibiotic resistant, cropped up in the intestines within two weeks of receiving these mercury leaking fillings.

It is far more sensible to evaluate what happens to humans. This has been done repeatedly with consistent negative results. Since dentists are regularly exposed to mercury vapor from the drilling out of old fillings, if adverse effects were to occur, one would expect to see among in dentists. Although dentists have higher urinary mercury values than the general public, their death and disease rates are no higher [11]. In 1993, an extensive review by the U.S. Public Health Service concluded that it was inappropriate to recommend restricting the use of dental amalgam [12]. Since that time, many more studies have demonstrated that amalgam fillings do NOT cause any ill effects [13-14].

Narrator: Further studies have found damage to the ADP ribosylation of brain neuron proteins. In response to the controversy, and at the request of the Federation of Experimental Scientists and Biologists, Drs. Fritz Lorscheider and Murray Vimy wrote an editorial, the first ever in FASEB that point-by-point refuted the claims of the amalgam proponents.

Publication of the letter should not be regarded as evidence of scientific acceptance or credibility. The journal also published a rebuttal that quoted from the Public Health Service review [15].

Narrator: In 1991, the World Health Organization acknowledged that the predominant source of human exposure to mercury is from your fillings. That should be of concern to anyone wanting to have healthy children because mercury is highly damaging to fetuses. Experiments in sheep showed that mercury from the sheep's fillings transferred immediately to the placenta, to the unborn fetus, and to every conceivable portion of the fetuses' body. It even increased in the lamb higher after birth from mercury in the mother's milk.

The video did not indicate the source of the statement the video attributes to the World Health Organization. But, as noted above, it is well established that amalgams are not the major source of human exposure to mercury.

Narrator: There is no such thing as a safe mercury filling. All mercury fillings leak mercury.

The primary rule of pharmacology is the "the dose makes the poison." in other words, the amount of an alleged toxin must be high enough to damage the victim. Multiple studies have shown no ill effects from a mouthful of amalgams and even dentists, who have more mercury in their body than the average person does, do not have higher incidence of any disease.

Narrator: The combined effect of mercury, cadmium, and lead is just now being investigated but it's not one-on-one. It's synergistic and one-on-one may make 100 or even 1,000. Why is that of concern? Over and over again, we've heard that children are exposed to lead from our environment. Mercury and lead is many times more toxic than just mercury alone. These black corroded, pitted, mercury fillings are used where you must drill away a third of the tooth in order to fix a pinhead sized cavity even if you love mercury. It's the wrong thing to do to the children. It leads to broken, diseased, root-canaled, extracted teeth throughout the rest of the life. It's a blender that costs the child all through their life. Millions and millions of dollars are spent annually fixing teeth again and again. And dentists don't follow the manufacturer's recommendations. They pack mercury in children around the gold crowns underneath bridges. They stuff it around the gum line in contact with tissues. There's mercury spreading from this gold crown to every tissue in that patient's body. Even if you like mercury fillings, putting that kind of filling in the tooth is simply the wrong thing to do.

Dentists do not "drill away a third of a tooth" to fill a pin-hole cavity. Indeed far fewer fillings are being done due to fluoridation and sealants.

Narrator: Harold Lowe, the former director of the National Institute of Dental Research back in 1993, wrote, "The first filling is a critical step in the life of a tooth. Using amalgam for the first filling requires removing a lot of tooth substance and not only diseased tooth substance but healthy tooth substance as well. So in making the undercuts, you sacrifice a lot, and this results in a weakened tooth." The next thing you know the tooth breaks off and you need a crown. Then you need to repair the crown, and so it continues to the stage where there's no more to repair and you pull the tooth. With the first filling, you should do something that can either restore the tooth or retain more healthy tooth substance. Use new materials, composites, or materials that can bond to the surface without undercuts. You can do this with little removal of the tooth substance so that the core of the tooth is still there.

This is from a statement that is 22 years old. Today, dentists do "minimally-invasive" dentistry, attempting to remove as little tooth structure as possible. In addition, amalgam is very durable [16]. IOAMT's assertions that amalgam is prone to deteriorate have no data to back them up.

I would add that the cost of all that dental repair over and over again makes the cost of mercury fillings enormous. Even if you don't consider the neurological impairment and the brain damage that they surely cause in dental personnel and the infertility and the heartbreak that they've caused in so many families.

Not true. In 2007, an expert team concluded that if amalgam were banned, overall dental costs would rise more than $8 billion a year and millions of people would let their dental disease go untreated [17]. The poorest members of our society would be hurt most because composite or gold restorations are much more expensive than amalgam fillings.

Narrator: It is the opinion of this academy that responsible government agencies should prohibit the use of these fillings until such time as their manufacturers produce the alleged evidence of safety.

Fortunately, the U.S. Food and Drug Administration has repeatedly denied IAOMT's petitions for a ban.

The Bottom Line

The amount of mercury absorbed from amalgam fillings is only a small fraction of the average daily intake from food and is far below the level that exerts any adverse health effect. Thus there is no logical reason for consumers to be concerned about "amalgam toxicity." The American Dental Association considers "the removal of amalgam restoration from the non-allergic patient for the alleged purpose of removing toxic substances from the body, when such treatment is performed solely at the recommendation or suggestion of the dentist, is improper and unethical" [18], and some state licensing boards have disciplined dentists for unnecessarily removing them. IAOMT represents a fringe viewpoint and should be ignored.


  1. Barrett S. My concerns about "holistic" and "biological" dentistry. Quackwatch, March 28, 2015.
  2. Kall J and others. International Academy of Oral Medicine and Toxicology (IAOMT) position statement against dental mercury amalgam fillings. April 16, 2013.
  3. Foulke JE. Mercury in fish: Cause for concern? FDA Consumer Sept 1994, pp 6-9.
  4. Precautionary principle. Wikipedia, accessed Nov 10, 2015.
  5. Laidler J. "Smoking teeth"—The truth gets "smoked out." Confessions of a Quackbuster Blog, April 6, 2005.
  6. Olsson S, Bergman M. Daily dose calculations from measurements of intro-oral mercury vapor. Journal of Dental Research 71:414-423, 1992.
  7. Vimy MJ, Lorscheider FL. Intra-oral air mercury released from dental amalgam. Journal of Dental Research 64:1069-1071, 1985.
  8. Baratz RS. Dubious mercury testing. Quackwatch, Feb 19, 2005.
  9. Makert JR Jr, Bergland A. Mercury exposure from dental amalgam fillings: Absorbed dose and the potential for adverse health effects. Critical Reviews in Oral Biology and Medicine 8:410-436, 1997.
  10. Berglund A. Estimation by a 24 hour study of the daily dose of intra-oral mercury vapor inhaled after release from dental amalgam. Journal of Dental Research 69:1646-1651, 1990.
  11. Dodes JE. The amalgam controversy: An evidence-based analysis. Journal of the American Dental Association 132:348-356, 2001.
  12. Dental Amalgam: A Scientific Review and Recommended Public Health Service Strategy for Research, Education and Regulation. Final Report of the Subcommittee on Risk Management of the Committee to Coordinate Environmental Health and Related Programs. U.S. Public Health Service, Jan 1993.
  13. Review and Analysis of the Literature on the Health Effects of Dental Amalgams. Life Sciences Research Organization, 2004. Updated 2015.
  14. ADA Council on Scientific Affairs. Amalgam safety update. Sept 2010.
  15. Dodes JE. Mercury in dental amalgam. The FASEB Journal 9:1499, 1995.
  16. Barrett S., Baratz, RS. How dental restoration materials compare. Dental Watch, Oct 30, 2008.
  17. Beazoglou T and others. Economic impact of regulating the use of amalgam restorations. Public Health Reports 122:657-663, 2007.
  18. Dental amalgam and other restorative materials. Advisory opinion 5.A.1. In ADA Principles of Ethics and Code of Professional Conduct. Revised April 2012.

This article was posted on November 14, 2015.

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