Dr. Robert F. Kidd    

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Mercury Poisoning From Amalgam Fillings

See also: Dental and General Health, Autonomic Response Testing

Amalgam dental fillings may be a health hazard to some people. Although a great deal of controversy still exists about this subject, even those who consider dental amalgam safe agree that the health of at least some people is affected by amalgam fillings. The big question then is: How do we identify these people?

This is a very complex subject and easy answers are hard to come by. However we do know the following facts:

  • Amalgam fillings are typically 50% mercury, 35% silver, 9% tin, 6% copper, with a trace of zinc.
  • Mercury vaporises at room temperature and is constantly released into the mouth from amalgam fillings.
  • Mercury is extremely poisonous and the symptoms of mercury poisoning have been known for almost 200 years.

Although these facts are beyond question, there is no agreement that enough mercury vaporises from fillings to cause problems. And to make matters more difficult, there is no laboratory or other test that can prove that there is a toxic level of mercury in the body.

There are a host of other problems as well. If amalgam fillings have been in use for 170 years, why has the problem taken this long to be detected? Why are some people made sick by relatively few fillings, yet others live long healthy lives with many? Why can’t scientists agree?

Before trying to answer these questions, let us have a look at some background.

History of Amalgam Fillings

The first crude amalgam fillings were developed in the early 1800’s. They appeared to be an inexpensive alternative to gold and other materials, but right from the beginning there was concern about the possibility of mercury poisoning. The dangers of mercury poisoning were already well known from the experience of the hatters of the day who spread mercury onto their beaver hats to make them shiny. The “Mad Hatter” of Alice in Wonderland provides a classic example of the memory loss and unpredictable moods that result from slow poisoning by mercury.

The American Dental Society in the 1830's felt strongly enough about this risk that its members were required to take an oath that they would never use it. However as the years went by, amalgam became accepted again and because of its cheapness and excellent mechanical properties has been the standard dental filling ever since. Only occasionally have alarms been raised about health risks.

Symptoms and Signs of Mercury Poisoning

  • Fatigue
  • depression
  • Memory loss
  • Difficulty concentrating
  • Difficulty making decisions
  • Anxiety
  • Insomnia
  • Headache / backache
  • Muscular or arthritic aches
  • Burning hands or feet
  • Tremor
  • Fibromyalgia
  • Cold hands and feet
  • Metallic taste in mouth
  • Tinnitus
  • Certain types of kidney disease
  • High blood pressure
  • Low body temperature
  • Eye problems
  • Sinusitis
  • Gum disease
  • Thyroid disease
  • Palpitations or irregular heartbeat
  • Bladder irritability
  • Loss of sexual interest
  • Yeast syndrome
  • Food sensitivities
  • Sensitivity to perfumes and chemicals
  • Frequent sore throats
  • Problems with vision
  • Gastrointestinal problems

Some Comments about Toxicology

Toxicology, or the study of the effect of poisons, is a more complicated subject than one might first think. Poisons do not always affect people the same way. Some people are affected by very small doses, and the type of symptoms may vary from one person to another. Also if the poisoning takes place over a long time and affects many people, the symptoms may be accepted as a part of everyday life.

For example, it is felt by some that the Roman aristocracy’s lead glazed dishes may have caused chronic lead poisoning. This would have resulted in infertility and poor health, and may have contributed to the subsequent decline of the Roman Empire. Even in recent times, tobacco smoking with its tar and nicotine poisoning have been so common that early heart attacks and lung cancer have been accepted as a part of modern life.

Poisons, particularly the heavy metals like mercury, lead and cadmium may affect many parts of our body machinery. In some people only a few of the above list of symptoms will result, but in others there will be many. Unfortunately these symptoms may also be caused by many other types of illnesses. For example, fatigue and headache, may be caused by not only mercury poisoning, but also by nutritional deficiencies, emotional stress, reactions to medication, or even the flu. No single symptom of mercury poisoning is so specific that it could not be caused by something else.

Diagnosis of Mercury Poisoning

In cases of acute (recent, short-lasting) poisoning, diagnosis is straight-forward. If the symptoms and the doctor’s physical examination raise suspicion, blood and urine may be tested for toxic levels of mercury. This is the usual way of diagnosing poisoning from contaminated foods, industrial exposure, accidents with mercury thermometers, etc.

With chronic (low-grade, long term) poisoning, diagnosis is more difficult. The symptoms have usually begun gradually and are sometimes so subtle that the patient hardly realises that he or she is unwell. This is particularly true of fatigue, memory loss and aches and pains that are often blamed on ageing. Blood and urine tests are mostly useless here, although hair analysis will sometimes show mercury if the source is certain forms of mercury, as in some fish.

If mercury poisoning is from dental amalgam (the most common source), no simple lab test will help. The reason for this is that mercury from amalgam enters the body as a vapour. Mercury vapour can penetrate and bind to the body tissues and for the most part does not circulate in the blood. This is in contrast to mercury from other sources, which comes in the form of salts, circulates in the blood and does not penetrate the tissues as easily.

How then can chronic mercury poisoning from amalgam be detected? The first step is to be suspicious in every person with symptoms who has (or has had) amalgam in the mouth. If there are amalgam fillings in the mouth, there is without exception mercury in the body. There may be no symptoms of poisoning, but the risk is there. Mercury poisoning is common, although in many cases it is mild with symptoms coming and going. This variability in severity of symptoms occurs because the symptoms depend on more than just the amount of mercury present. Other factors like nutritional status, stress levels, and the presence of other toxins may be at least as important.

Another key to diagnosing mercury poisoning is to note the relationship between dental work (of any kind) and the onset or worsening of symptoms. If the onset of symptoms coincides with removal of old fillings or placement of new ones, think mercury poisoning. Removal of old fillings releases a large amount of mercury vapour that may be just enough to precipitate symptoms. It is not rare for patients to experience a sore throat or “canker sores” after professional teeth cleaning. This is due to stirring up mercury from the surface of the fillings.

The symptoms of mercury poisoning may also “come to the surface” during or after some other stress to the body’s metabolism. A strict low-protein diet, (e.g. Weight Watcher’s diet or vegetarian diet) may result in symptoms because the body is no longer able to eliminate enough mercury to keep up with the constant intake from amalgam fillings. Symptoms may also be provoked by minor exposure to another toxin, (e.g. formaldehyde or a prescription drug), as many poisons share the same detoxification pathways in the liver. It is as if the liver is able to keep up with one toxin, but not two together. Because the exposure is often minor, e.g. new carpets in the home, no connection may be made between the illness and toxic exposure to the carpet fumes or anything else.

Your doctor’s physical examination may pick up clues to help in the diagnosis. Patients with chronic mercury poisoning often are pale and have dark circles around their eyes. They may seem prematurely aged, may appear depressed or vague in their response to questions. Despite normal thyroid tests, their body temperatures are always low. “Tattoos” are sometimes visible where mercury has leaked from a filling into the surrounding gums. The gums adjacent to amalgam-filled teeth may appear irritated, pale or swollen. A fine tremor of the tongue, the mouth, or muscles anywhere else in the body may be present. The onset of high blood pressure, especially after dental work, should raise suspicion, as should irregular heart beat in a person without heart disease.

Routine laboratory tests are usually normal, but if unexplained protein is found in the urine, mercury poisoning could be a cause. As mentioned above, blood, urine and hair analyses are of little help in chronic mercury poisoning from dental amalgam.

There are only two everyday methods of “testing” for excessive levels of mercury in the body. One is called the “DMPS Provocation Test”; the other is “Autonomic Response Testing” or ART.

DMPS Provocation Test

DMPS or dimercapto-proponyl-sulfite is a chelating agent for mercury, and to a lesser extent other heavy metals. Chelating agents are substances which when injected into the body, pull heavy metals out of the tissues, and eliminate them through the kidneys. Although DMPS is not an approved drug in North America, it is very safe when used properly, and has been used and researched in Europe and China for over 40 years.

DMPS can be used in treating mercury poisoning, but may also be used as a test to measure the amount of mercury in the body. The test works this way:

  1. A standard amount of DMPS is injected into a vein,
  2. The urine is collected immediately afterward (for 6 or 24 hours),
  3. The mercury in the urine is measured.

Unfortunately there are two limitations to this test. Firstly it may not be safe to use this test in patients who already have fillings in their mouths. There is some evidence that excessive mercury may be mobilised from the fillings that can overwhelm the kidneys and/or liver. For this reason, this author will do this test only after the fillings have been removed. The other limitation is that there is no evidence that the severity of a patient’s illness is proportional to the amount of mercury found in the urine. In other words, sometimes a great deal or mercury can be extracted from someone who is not particularly ill. Yet in others who are very ill, sometimes little mercury can be found in the urine.

The DMPS Provocation Test is a valuable tool, especially in research, but must be interpreted with caution in individual patients.

Autonomic Response Testing

Autonomic Response Testing is a controversial method of testing for mercury poisoning. It has not been tested scientifically; in fact it may be impossible to prove that it works within the present understanding of science. This is because the tester (usually the physician) is involved in eliciting a response in a subtle and not yet understood way. For this reason, care must be taken that neither the patient’s nor the physician’s biases influence the patient’s response.

Autonomic (Nervous System) Response is the body’s “Aha!” reaction to a stimulus affecting it in a very basic way. The stimulus may be a touch to the body, a smell, a picture, or even an emotionally evocative word. The stimulus may be good or bad from the body’s perspective, but the response is the same.

One of the most difficult to understand phenomena is the response elicited by a substance that is simply placed near the body. The substance may be a potential help, (e.g. a vitamin or even an appropriate medication), or a threat. (e.g. a toxic substance). If the body recognises the substance as having meaning to it, there will be an autonomic response.

The autonomic response may be observed in several different ways. There may be a slight increase in heart rate, the pupils may dilate, there may be a change in the electrical properties of certain acupuncture points, or there may be a change in muscle (any muscle) strength. These responses are subtle but measurable. In the case of potential mercury poisoning, mercury (or a substance that will treat mercury poisoning), is placed near the body. If an autonomic response is elicited, one can suspect that the level of mercury in the body is high enough to be causing problems.

This is a highly subjective test and must be used with great caution. No important decision should be based on an autonomic response test alone. Its value lies in confirming or questioning a diagnosis that is close to being made.

Treatment of Chronic Mercury Poisoning

The first decision to be made is whether treatment is needed or not. As mentioned above, everybody with amalgam fillings has mercury in their bodies. Even those without amalgam fillings have mercury in their bodies to a certain extent from contaminated food, medications, cleaning agents, and other sources in our environment. Our bodies have natural ways of detoxifying this mercury, and in most people this is adequate to keep them healthy.

With our present knowledge, people who have amalgam fillings and who are healthy, should probably not have their fillings replaced, except as they naturally break down. When fillings do break down, they should be replaced with composite “white” fillings. Although they are not quite as strong as amalgam fillings and may not be entirely free of risk, they are probably far safer than amalgam for general health.

For those who are experiencing symptoms of mercury toxicity, the first step is to strengthen the body’s own ability to detoxify. Nutrition is the key, especially of minerals and dietary protein. Heavy metals are minerals too, and if the body is short of “good” minerals, “bad” minerals will take their place. Protein is important because it provides the amino acids that act as natural chelators of heavy metals. Vitamins also assist the detoxifying processes and are often in short supply in patients who are toxic. Blood tests to evaluate nutritional status and the body’s ability to detoxify may be necessary.

The next step is to find a dentist to replace the existing amalgam. This is an important decision as many dentists are completely unaware of how sick people can be made from the mercury vapour released during filling removal. Careful technique is essential and skill with the use of composite fillings will make the process faster. Ideally the dentist should be a “holistic dentist” who has taken special training in this field. A training and certification process for dentists is available through the International Academy of Oral Medicine and Toxicology. At the very least, the dentist should not be using amalgam in his or her practice at all.

Before the dental work is done, the patient should be on a nutritional and oral detoxification program for at least six weeks. If possible, all the dental work should be done in one sitting, or if this is not possible, in sessions a few days apart. As soon as the dental work is done, preferably on the same day, the patient should have intravenous DMPS chelation, with a high dose of Vitamin C and other intravenous nutritional support. The urine should be collected immediately after to measure the excretion of mercury and other minerals. This helps to determine how effective the chelation has been and to plan further strategy.

During the same visit, the physician should check, using autonomic response testing, that the organs most affected by mercury poisoning are functioning well. If they are not, (are in an off-balance or are under stress), they should be treated with neural therapy to stimulate blood flow through the affected tissues.

The first day after the amalgam removal and medical treatment, it is normal to feel somewhat tired, and perhaps a bit vaguely unwell. This should settle within a day or two, but should it not, the physician should be contacted, as it is possible more neural therapy or intravenous vitamin C is needed. This sort of reaction is rare.

After the chelation, the patient should continue on a nutritional program with follow-up visits with the physician each month. DMPS injections are given each month and neural therapy, if necessary. On the third month, a repeat urinalysis is performed. The number of DMPS injections is determined by the patient’s response, the amount of mercury in the urine, and autonomic response testing.

Response to Treatment

The occasional patient feels improvement immediately after the first treatment. Most begin to slowly feel improvement after a couple of months. It is usually quite gradual and hardly noticeable at first. Most patients require six months of treatment but some will need a year or more.

There is no guarantee that all patients will improve with this approach and that all symptoms will disappear, but in patients without serious underlying diseases, an 80% success rate has been achieved.