How the tooth filling placed in good faith by your family dentist can damage your health

By Dr Ilona Visser

Published in Journal of Natural Health Issue 22, Feb/March 2006

Amalgam literally means ‘mixed with mercury’, and it is the most common form of tooth restoration. The earliest record of the use of a ‘silver paste’ in teeth is in the materia medica of Su Kung from 659 AD. Alchemists were fascinated that mercury appeared to ‘dissolve’ powders of other metals such as silver, tin, and copper at room temperature. In spite of the pandemic use of amalgam as a tooth filling material, most dentists and doctors are still ignorant about the levels of mercury exposure and its health implications. It seems that a lack of interdisciplinary research and of a critical approach to established clinical routines appears to be the reasons for the failure of the dental profession to protect the patient from mercury exposure when saving a tooth.

The ‘amalgam wars’

During the last millennium amalgam has been frequently accused of initiating diseases. The first time was around the 1830s when the French non-dentist brothers Crowcour mixed French silver coin shavings and liquid mercury to form amalgam and, posing as dentists, they introduced their mixture to New Yorkers.

It was well known during the post-Napoleonic era that mercury was toxic, causing dementia and loss of motor control. The U.S. National Association of Dental Surgeons banned any dentist who used amalgam, and jokingly referred to these dentists as ‘quacks’ (derived from the English translation of the German word for mercury, ‘quacksilber’).

In 1859 this association was replaced by the American Dental Association (ADA), the same organisation that leads the dental fraternity today. The newly formed ADA frowned upon dentists who preferred working with the less toxic but more expensive gold and refused to place amalgams.

More than 40 dentists in the USA are currently delicensed by the ADA due to their stand against the use of amalgam. This is one of the reasons that dentists are not willing to openly oppose the use of amalgam.In the 1920s and again in 1939 Dr Alfred Stock, a German chemist, warned against the use of mercury due to the dangers of mercury vapour. He himself became forgetful and ill after being exposed to mercury in the laboratory. Due to the abuse he suffered from organised dentistry after he published about 30 scientific articles on the matter in leading scholarly journals of the day, he withdrew from the ‘war’.

The third movement started in 1973. Mass spectrophotometry and the Jerome mercury vapour detector were now able to detect the presence of trace amounts of mercury in amalgam fillings. In 1976 the ADA, after vehemently denying for many years that amalgams release mercury, had to acknowledge that it does, in fact, release mercury. They subsequently developed and patented a mixture with less mercury, but more copper, known as the non-gamma 2 amalgam, which is widely used today.

Show me the science

The pro-amalgamists support their opinion based on statements made by the ADA. Since the majority of dentists in North America rely on the guidelines of the ADA, their views carry a heavy weight in the dental community. The ADA relies on the long use (more than 160 years) of amalgam as the strongest and most convincing reason for their support of the product. This is quite scary, as we are even now in the midst of a battle between pharmaceutical companies and the public regarding the use of drugs proven to be detrimental to health, and these are drugs that were even approved by the Food and Drug Administration (FDA) (amalgam is not FDA approved). The following facts pertaining to the toxicity of dental amalgam have been proven:• Amalgam releases significant amounts of mercury• Amalgam is the largest source of mercury to the body• Mercury is distributed to organs and tissues in the body• Mercury crosses the placenta and is present in breast milk• Adverse physiological changes occur after mercury exposure• Mercury interferes with cell metabolism. Lets look at these facts in more detail.

Amalgam releases significant amounts of mercury

The ADA states that mercury is not toxic when used in dental amalgam, since, when mercury is combined with other metals such as silver, tin, and copper, it reacts with these metals to form a biologically inactive substance. This has been proven wrong.

A photomicrograph of a polished piece of amalgam was touched (not pressed) by a probe (such as the one dentists use to examine teeth). The surface clearly showed droplets of free liquid mercury that was squeezed onto the surface of the amalgam. This was done without heating the amalgam. Actually, even when the amalgam was cooled down to the temperature of liquid nitrogen, mercury droplets still appeared. (You can view this image as well as many others mentioned in this article on the website of the International Academy of Oral Medicine and Toxicology, www.iaomt.com.)¹

As early as 1991, the World Health Organisation (WHO) declared that there is NO SAFE LEVEL of mercury exposure. So any exposure to mercury is toxic. When a tooth containing an amalgam filling, which had been in a tooth for 25 years, was placed in front of a screen illuminated by a pure mercury vapour discharge lamp ‘smoke’ was seen emerging.¹ According to the principle of atomic absorption spectrophotometry, the only cold vapour that could absorb the wavelength of mercury emission light and cast a shadow, would be mercury itself. According to the WHO, when one can visibly see the mercury vapour (such as in this case), it is already 1 000 times higher than the U.S. Environmental Protection Agency (EPA) will safely allow for the air that we breathe.²

Amalgam is the largest source of mercury to the body

In 1991 the WHO⁶ concluded that, by using the average number of amalgam surfaces that a person has, they would absorb between 3 - 17 micrograms mercury/day, with 10 micrograms/day being the average. Other sources of mercury rendered far less absorption (from food 2.3 microgram/day, and from all other environmental sources 0.3 microgram/day).For many years the ADA maintained that amalgams did not release mercury, despite the fact that several scientists were not just able to prove that mercury is released, but were even able to measure the amount of mercury vapour released by amalgams. During one of these studies, after the persons had been chewing gum for only 10 minutes, this vapour increased 8 - 10 fold, and remained elevated for at least 1.5 hours (Fig. 3).^3,4 An average absorbed mercury dose of 10 microgram mercury/day from amalgam fillings from measurements of mouth air was found.³Canadian authorities appointed a Canadian scientist, Mark Richardson, to determine the tolerable daily intake of mercury (that is the amount of mercury that the body can be exposed to without health problems developing). This was after Health Canada was sued in the early 1990s by a group of consumer activists. Richardson found that many people, of all age groups, were actually exposed to five times more mercury than the tolerable daily intake which he had determined, and that a fifth of the population had central nervous system and/or kidney impairment as a result of amalgams, but without having any symptoms (therefore subclinical).⁵ Back in the U.S., the Agency for Toxic Substances and Disease Registry (ATSDR) published2 the minimal risk level (MRL) for non-occupational exposure, which, when related to amalgam fillings, would mean that even one amalgam would expose the patient to more mercury than the ATSDR allowed.

Mercury is distributed to organs and tissues in the body

Nearly 50 years ago a scientist, KO Frykholm, placed four amalgams containing radioactive mercury in eight volunteers’ teeth (it is very doubtful if this experiment would be allowed today!).⁷ He concluded (incorrectly according to the basic principles of toxicology) that the release of mercury from the fillings was not a health problem. According to the basic principles of toxicology he should not have concentrated so much on how much mercury was excreted, but on how much mercury was absorbed and retained, and could therefore be harmful. Unfortunately this is one of the main studies pro-amalgamists rely on when supporting amalgam use.In order to demonstrate the absorption of mercury (released by amalgam fillings) by the body’s organs, amalgams containing radioactive mercury (²⁰³Hg) were placed in a sheep’s teeth. Within 30 days the mercury was present in the walls of the digestive tract, kidneys, gums, jawbone (alveolar), and liver.8,⁸ Dentists reacted to this study by claiming that sheep eat and chew differently from humans. The authors responded to this criticism by saying that the sheep represented the ‘exacerbated case’. If the absorption of mercury from amalgam could not be found in such a chewing machine as a sheep, the case would be closed; the controversy over, and amalgams could be placed with a clear conscience. The study was then repeated on monkeys, since they eat much the same food and chew in much the same way as humans.⁹ It only confirmed the initial results. Several studies have shown that, when the number of amalgams increase, the following also increase: amount of mercury absorbed, mercury level in the blood, amount of mercury excreted in the faeces, and amount of mercury retained in the body.^10-13 When the amalgams were removed, all these levels dropped.¹⁴ When looking at studies done on the mercury content of urine and blood, it should be remembered that stat urine (a “once off” sample taken any time during the day) mercury content is only a reflection of the amount of mercury that the kidney (as a target organ of mercury) cannot absorb, and that the kidney lets through into the urine, since only 1% of mercury is excreted via urine. DMPS (2.3 dimercapto propane 1 sulfonic acid), a chelating agent that is used to remove toxic metals from the body, was given to a group of subjects with amalgam fillings, and a control group of subjects who had never had amalgams. This is called a challenge test. When taking a urine sample, the level of mercury should be below 0.5 microgram mercury/gram creatinine excreted (the form in which the laboratory reports the mercury content of the urine sample). Urinary excretion of mercury in the non-amalgam group increased from 0.27 microgram mercury/gram to 5.1 microgram mercury/gram over a 9-hour period, while among the amalgam subjects it went from 0.7 microgram mercury/gram to 17.2 microgram mercury/gram. A highly significant correlation was found between the number of amalgam fillings and urinary excretion of mercury.Autopsy studies showed significantly higher mercury levels in the brain and other body tissues in subjects with dental amalgam (than in those without amalgam), and the mercury levels correlated significantly with the number and age of dental amalgams. In 1976 the ADA reiterated that amalgams do not cause any health problems to dental personnel. However, when dentists were examined after using challenge tests, the results showed high urinary levels of mercury, and this correlated with neuropsychological and motor control deficits. Dental staff also showed altered porphyrin metabolism, as well as neurobehavioral changes, including impairment of attention, motor and perceptual skills, and increased irritability. It might be time that dentists who place and remove amalgams received danger pay! From all the patients that have been tested after a chelation challenge, I have thus far had only one patient with a normal level of mercury, and he did not have any amalgam fillings. In fact, in the majority of cases the results are more than 80 (the normal level is less than 0.5), and even as high as 250 microgram mercury/gram creatinin, with patients sufferring from various health problems.

Mercury crosses the placenta and is present in breast milk

Developing babies and young children are disproportionately affected by mercury exposure, because many aspects of their development, particularly brain maturation, can be affected by the presence of mercury. Following placement of radioactive labelled mercury in amalgam in pregnant sheep’s teeth, it was found that both ewes and lambs showed mercury absorption within 2 days of placement of the fillings. The levels increased for about 30 days, and then remained constant right up until 140 days (after which the last measurement was taken and the experiment closed). This verified that the mercury found was not due to the initial placement procedure alone (as some would claim), but largely due to the continued release of mercury from the fillings. There was actually more mercury in the foetal blood than in the mother’s blood. Even foster lambs, (whose mothers did not have amalgams) which suckled from the ewes that had amalgams, showed mercury in the body. Autopsies from human stillbirths and early postnatal deaths showed that the more amalgam fillings the mother had, the more mercury was in the infant’s brain, kidneys and liver. Human breast milk mercury levels corresponded with the number of amalgams that the mother had.

Adverse physiological changes occur after mercury exposure

Inorganic mercury can cause acute damage to the digestive tract when given orally, and, if the animal survives, necrosis of the proximal tubule of the kidney occurs.

Immune system

In 1972, by using skin patch testing, it was found that 5 - 8% of the population in the USA was allergic to mercury (not less than 1%, as the ADA claims). Any normal cell with even one molecule of mercury attached is seen by the immune system as a foreign cell, and can activate the immune system to fight the ‘invader’, thus the start of auto-immune disease.

Mercury increases immunoglobulin E (IgE) in blood and immune complexes in the kidneys, and activates the induction of oligoclonal T-cell responses, therefore not restricting the immunomodulatory properties of mercury to pure contact allergy. By using specialised blood tests (a far more accurate method of determining allergies) mercury allergy was found to be over 90%. This proved the previous skin patch testing for mercury allergy futile.

Mercury-containing amalgam may be an important risk factor for patients with autoimmune diseases. MELISA^® testing can be used to monitor metal allergies. In a study conducted to determine if genetically susceptible individuals would have allergic reactions to mercury and elicit allergic and autoimmune reactions, it was found that an inflammatory process induced by metals may modulate the hypothalamic-pituitary-adrenal axis and thus trigger multiple non-specific symptoms characterised by chronic fatigue syndrome and other chronic conditions such as myalgic encephalitis and multiple chemical sensitivity.¹⁵

Renal system

Sheep studies showed an average of 54% decline in function of the kidneys (inulin clearance) after amalgams were placed. The sodium in the urine increased (mercury concentrates in the proximal tubules in the kidney, where the sodium re-uptake takes place), and the albumin decreased. In humans the urinary albumin were still increased a year after amalgams were removed. After a single dose of mercury the acute renal damage can be rapidly repaired, but repeated exposure to mercury causes fibrosis of the kidney.

Reproductive system

Dental nurses have been shown to have a fertility rate of only 63% compared to that of a control group. Many other studies have shown the negative effect of mercury on the reproductive system.

Central nervous system

The brain is a critical target organ for mercury. There is substantial literature available on the neuro-teratological effects of mercury, where animals exposed to low doses of mercury in utero and soon after birth showed measurable deficits in intelligence, co-ordination, and other measures of neurological development. Vaccines preserved with thimerosal, a form of ethyl mercury, are also thought to cause neurological damage in infants, including autism.Professor Boyd Hayley (protein biochemist, University of Kentucky) found that there were similar biochemical and cellular changes in brain tissue of Alzheimer patients and brain tissue that was exposed to mercury. Only one paper, published in a non-scientific non-referenced journal, could not find an association between Alzheimer’s disease and mercury. This is in stark contrast to many studies published by Professor Hayley and various other scientists in peer-reviewed scientific journals.^16,17 A genetic susceptibility for mercury toxicity and neurological damage was also found.One of the few laboratories in the world that has the capacity to maintain growing neurons (nerve cells) in tissue culture is at the University of Calgary Medical School, Canada. Recently, a group there published a paper and an accompanying video¹⁸ that showed how very low concentrations of mercury chloride caused the tubulin in the growth cones of young neurites to fall apart.

Table 1. A summary of the subjective reports of 1 569 patients who participated in six different surveys of health effects improving after replacement of amalgam fillings. Only the top 85% are reported here.

In the case of mercury, essential metabolic systems such as reduced glutathione, metallothionines, and apolipoprotein-E double as protective elements. There are, however, genetic variations and polymorphisms to these elements that inevitably leave some individuals more vulnerable to assault. This explains why some people with amalgams will not have any clinical effect, while others do.The Internet and lay publications are full of anecdotes from people who claim that their health improved once their amalgam fillings were replaced with other materials. Although their stories do not constitute truelly scientific “cause and effect evidence”, these are real people with real-life experiences. In order to satisfy scientists the amalgams were indeed the culprit, the amalgams would have to be replaced, and notes made if the symptoms recurred. Not many people, whose lives were affected by amalgams, would be prepared to go through that ordeal again!

Oral and intestinal flora

Table 2. Disorders Linked to Chemical and Metal Toxicity (Source: www.true-chelation.co.za)

The following is a list of the most common disorders found by research studies to be directly linked to toxic metals and chemicals:

· Attention Deficit Disorder · Alzheimer’s Disease · Asthma · Arthritis · Autism and Autistic Spectrum Disorders · Auto-immune Disorders · Candidiasis · Chronic Fatigue Syndrome, · Cancer · Epilepsy · Fibromyalgia · Heart Diseases · Hypertension · Chronic Insomnia · Infertility · Kidney Disease · Liver Disease · Lou Gehrig's Disease (ALS) · Multiple Sclerosis · Parkinson's Disease · Schizophrenia · Thyroid and Adrenal Disorders

What is happening in other countries?

The largest experiment in the world on mercury released from amalgam fillings into the saliva, known as the Tübingen amalgam tests, was conducted in 1995 on 20 000 people. The results clearly showed that the more amalgam fillings, the higher the level of mercury load. This prompted interest groups to seek a ban on the use of dental amalgam. Since then various Scandinavian countries such as Sweden and Denmark placed restrictions on the use of dental amalgam, and, according to a well known dentist practicing in Geneve, if amalgam is found on the premises of Swiss dentists, these dentists can be criminally charged. As of late, Sweden has completely banned the use of amalgam (it is treated the same as uranium), and Germany, Denmark and Norway do not allow amalgams to be placed in pregnant woman and children under 3 years. Germany has stopped the production of dental amalgam all together.In the USA Californian dentists are not allowed to place amalgams, and in Maine a dentist is required by law to warn a patient of the dangers of amalgam before placing amalgam fillings. The ADA has (at last), in its revised patient advice booklet, suggested that amalgams should not be used in children, pregnant women and women of childbearing age.So it seems as if mindsets are changing, albeit very, very slowly. Might it be that the ADA is bringing up a generation that will be amalgam-free? This would solve the problem of class action lawsuits, since no-one would then be alive any more who still had amalgams to file these lawsuits, and the ADA could finally agree that amalgams are detrimental to health.

Legal responsibility ‘ducked’

Even though purporting the ‘safety’ of amalgam, when facing a complaint against them in 1992, the attorney for the ADA, Robert S Luft, filed a demurrer stating that the ADA, as a voluntary professional organisation (a trade union), had no legal duty to protect the public from products used by dentists that might be dangerous. Furthermore, although responsible for the development of and training in the use of amalgam (through accreditation, done by the ADA, of US dental schools), the ADA does not manufacture amalgam, control the manufacturers, or place the amalgam in the patient’s mouth. Just because it disseminated information pertaining to the use of amalgam it did not place a responsibility on the ADA to protect the public from potential injury. When Judge Read Ambler ruled on the demurrer, he dismissed the case against the ADA, thereby placing all dentists who use amalgam on the hook for damages they might be doing when restoring patients’ teeth with amalgam.The ADA has maintained that mixed dental amalgam is a reaction product manufactured by the individual dentist, and it is the responsibility of the individual dentist to determine the efficacy of the materials and their appropriateness for each patient. With this view the ADA is conveniently placing all responsibility of using amalgams on the shoulders of the dentist.It would be reasonable to suspect class action lawsuits would be filed should the ADA admit that the use of dental amalgam must be discontinued due to possible health risks. Studies conducted by international auditors on the financial implications of large-scale class action lawsuits (which would make the asbestosis and cigarette lawsuits look like pennies in a bucket) found that there would not be enough printed money in the world to pay for the settlement of these lawsuits. The dental community would, for financial reasons, be hard-pressed to advocate health impairment as a reason to discontinue the use of amalgam.

Conclusion

As with asbestos, lead, Vioxx and DDT (all products that were used for many years), the initial safety was even supported by responsible government agencies. These products were eventually proven to be unsafe (although the evidence was initially discounted by the responsible industry). It might just be that history is repeating itself in the case of dental amalgam fillings, and just as in those cases, the legal ramifications might become overwhelming.

References

1. This picture can be seen at http://www.iaomt.org/articledetails.cfm?artid=3052. USEPA mercury health effects update.

2. Final report (1984) EPA-600/8-84-019F United States Environmental Protection Agency, Office of Health and Environment Assessment. Washington, D.C. 20460.

3. Vimy MJ, Lorscheider FL. Serial measurements of intra-oral air mercury: estimation of daily dose from dental amalgam. J Dent Res 1985; 64:1072-1075.