The term 'silver filling ' is a misnomer as a 'silver filling' contains 50% pure mercury and 35% silver with the remainder being made up of copper, tin and zinc. The mercury is the same metal that has been banned from thermometers in hospitals, schools and throughout industry because of its toxicity.
These fillings were originally used about 150 years ago as a cheap alternative to gold - the most common material in use at the time - which was too expensive for the vast proportion of the population. Consequently, 'silver fillings' were seen as the cheap alternative to gold. Even then, there was concern about the toxic affects of the mercury in the fillings and, although various dental associations banned its use at the time, economic forces won the day.
As each 'silver filling ' contains approximately 750-1000 milligrams of mercury, and other metals in the filling include silver, copper, zinc and tin (1), these fillings would more accurately be called mercury fillings. 75-80% of all tooth fillings are of this type (2).
At Dental School we were told that, once the filling was mixed, the mercury was locked into the filling and would not escape! Recently the British Dental Association admitted that the mercury in the filling does indeed escape.
The escape of mercury is affected by many things:
The above reasons explain why 'silver fillings' continuously release mercury vapour and its compounds into your mouth.
This low level, continuous, exposure to mercury vapour may be adversely affecting your health as even minute amounts of mercury vapour are very toxic.
The Environmental Health Criteria 101: methylmercury (WHO 1990) gives the following as estimated daily intakes of elemental inorganic and methylmercury.
Estimated average daily intake and retention (ug/day) of total mercury and mercury compounds in the general population not occupationally exposed to mercury, the figures in parenthesis are the estimated amount (ug) retained by the body of an adult.
No government department or authority anywhere in the world has ever certified 'silver fillings' as safe for use in humans, so we have no assurance that these filling are safe to use.
A risk assessment was recently carried out for the Canadian government by Dr. Richardson, a well respected risk assessor, who used all the available scientific data and came to the conclusion that up to 2 fillings in children and 4 fillings in adults would be an acceptable risk. Any more than this would be an unacceptable risk to the health of the patient.
Once the mercury is mixed with other metals in the filling it is 'locked in'.
Mercury vapour is continuously released from 'silver fillings' (4), more vapour is released by chewing (3-5); tooth brushing (6); and eating hot, salty or acidic foods or drinks (7).
The more 'silver fillings' you have, the more your daily exposure to mercury (4).
Once you have stopped chewing, it takes 90 minutes for the rate of mercury release to drop back to its pre-chewing rate (4,5). Thus you are susceptible to a roller coaster of mercury vapour all day. Breakfast will cause the release of mercury to rise, and just as it falls it's time for the mid-morning coffee break so the mercury release goes up again. This pattern goes on all day with lunch, mid-afternoon coffee, dinner and supper.
Mercury from 'silver fillings' is not retained and is in such small doses that it has no effect on the health of the body.
German (6), Swedish and American investigations (8) have found that human brain and kidney tissues from people with 'silver fillings' contained more mercury than those tissues of people without 'silver fillings'. The amount of mercury in the brain tissue of the people with 'silver fillings' correlated to the number of fillings they had i.e. the more fillings the person had, the higher the concentration of mercury in the brain tissues.
It has now been established that the mercury from dental 'silver fillings' constitutes the largest single source of inorganic mercury exposure to the general population - greater than all the other environmental sources combined (10). Despite replicated scientific findings, dental authorities maintain that 'silver' dental fillings are safe. They base this on the fact that the fillings have been in use for 150 years. They do not recognise that sickness or death might arise as a result of such fillings, and dentists are nether trained or licensed to determine mercury toxicity (11).
However, from the medical perspective 'silver fillings' are considered a significant source of mercury with significant potential for toxic impact. Medical researchers are now investigating the possible health risks of mercury from 'silver fillings'.
The latest medical research shows that mercury from 'silver fillings' accumulates in all the adult tissues, with the highest levels being found in the kidney and liver (13); and that, during pregnancy, mercury will cross the placenta and accumulate in the developing baby within two days of having a filling placed (14).
Although there have been reports to suggest a relationship between the presence of 'silver fillings' and human health, it is only recently that science has established a direct cause and effect link between 'silver fillings' and pathology.
Experiments carried out at the Departments of Medicine, Pathology and Physiology at Calgary University by M.J.Vimy, N.D.Boyd, D.E.Hooper and F.L.Lorscheider show a 50% reduction in kidney function in sheep one month after placement of 'silver fillings' and continues to fall after 60 days. The kidneys remove harmful substances from the blood, and maintain blood pressure and fluid balance. They also reabsorb essential nutrients and minerals. The loss of 50% of kidney function is like losing one kidney, and although healthy people can usually survive on one kidney, at times of stress it may not be ideal.
In another experiment, where mercury fillings were placed in the teeth of monkeys, it was shown that mercury from the 'silver fillings' dramatically altered the normal bacteria of the gut (16). In their place appeared mercury-resistant strains, which can also be resistant to antibiotics. Exposure to mercury may explain the rise in antibiotic resistant bacteria and the ineffectiveness of antibiotics which is a alarming problem in medicine.
Recent reports implicate mercury in certain brain dysfunctions. Autopsy data from patients who died while suffering from Alzheimer's disease show higher concentrations of mercury in brain areas associated with memory than an age-matched group who did not have Alzheimer's disease (17,18). Others have isolated a biological defect caused by mercury (19) which results in nerve tangles characteristic of Alzheimer's disease.
Scientific evidence overwhelmingly confronts the unsupported opinion of the dental profession.
The issue of the safety of 'silver fillings' is no longer open to debate.
Exposure to low level chronic mercury vapour can cause a number of non-specific, seemingly unrelated symptoms leading easily to misdiagnosis. Indeed, mercury exposure has been labeled 'the great masquerader'; the similarity of mercury related symptoms to other medical conditions makes it very difficult for doctors to make a correct diagnosis.
Unfortunately, only a very few doctors are aware of the release of mercury from dental fillings so therefore the correct diagnosis is even less likely.
1. Psychological disturbances
2. Mouth symptoms
3. General health symptoms
(a) Gastrointestinal symptoms
(b) Cardiovascular symptoms
(c) Neurological symptoms
(d) Respiratory symptoms
(e) Immunological symptoms
(f) Endocrine symptoms (glandular or hormonal)
(g) Skin symptoms
(h) Kidney symptoms
(i) Other symptoms
The symptoms of mercury exposure are very varied and confusing as they cover such a wide and diverse picture that mimics many other diseases.
Mercury is a toxic heavy metal which in small doses can be very detrimental to human health. It affects the body in 4 main ways:
Mercury is a heavy metal which, like lead and arsenic, is very toxic to the human body. Mercury is liquid at room temperature and so vapourizes very easily. The vapour is odourless, colourless, tasteless and when inhaled is very rapidly taken up by the blood and passes to all the other tissues of the body. Once in the tissues it enters the cells where it is converted into inorganic mercury. This highly reactive chemical reacts with sulphur containing enzymes. Enzymes are special molecules that promote chemical reactions that keep the cells, and therefore the tissues and body, alive. Without enzymes we would not be alive. Mercury's main mode of action is as an enzyme poison, with the final result being metabolic disease.
Allergic reactions to mercury and other compounds in 'silver fillings' can occur locally around the teeth, gums, or oral tissues. These reactions may occur immediately or take up to several years to develop. Symptoms may appear on other parts of the body (systemic) and, as with local symptoms, may appear immediately or take several years to appear. Typical systemic reactions would be eczema and sores on face or shoulders. General dental opinion is that less than 1% of the population is sensitive to mercury. Unfortunately scientific fact shows that approximately 5% of the population is allergic to mercury - that means that 5 out of every 100 patients in a dental practice may be allergic to mercury.
3. Mercury induced auto-immunity
The immune system is the body's defense system and protects 'you' from things that are 'not you' such as infections and cancer. Autoimmunity is a reaction in the immune system where it can't tell the difference between 'you' and 'not you' and so starts to attack healthy tissues. There are many specific auto-immune diseases e.g. Multiple Sclerosis, Lupus, Rheumatoid Arthritis. If you have any of these diseases, and are told that having your 'silver fillings' removed will cure you, please be very cautious. Choosing to have the mercury removed is a very positive health move and will reduce the mercury levels in your body, but it is not a scientifically proven cure for the disease.
4. Idiosyncratic reactions
Some people may be immunologicaly hypersensitive or toxicologicaly sensitive to very low doses of mercury and some individuals have idiosyncratic (strange) reactions. Often the symptoms are bizarre and difficult to diagnose, and may be included in a whole range of environmentally induced reactions totally unique to that individual.
One of the important issues facing medical research today is whether mercury from 'silver fillings' causes specific diseases. Many diseases today have no known cause and none of these have been shown to be caused by mercury from fillings. However mercury exposure, no matter how small, will cause mercury poisoning to some degree and so one should not ignore the negative effect mercury will have on your health. Removal of the mercury will be a positive health move. Remember mercury is more poisonous than both lead and arsenic.
Showing the impact that low level exposure to mercury vapour has on your health is very difficult. There is neither a single test that can show this, nor indeed any number of tests that are 100% accurate.
Lab tests will help to evaluate the following:
When should fillings be removed?
In this practice we do not use 'silver fillings'. If a filling needs to be removed we do not replace it with another' silver filling'. Where possible, it is replaced with a metal free restoration, preferably a composite. Options for fillings will be outlined to you later in the booklet. Other times when 'silver fillings' should be removed are outlined below:
The above represents reasonable criteria for the removal of 'silver fillings' based on current published scientific data and clinical experience.
'Silver fillings' have been the material of choice for the last 150 years because they are relatively cheap and simple to use, their biocompatability was of little or no importance in bygone days. The alternatives tend to be a little more expensive and clinically more demanding in the application.
They fall into 3 main types:
Gold alloys are a mixture of gold and other metals to make the gold harder, they are usually cast to make inlays, onlays or crowns.
The advantages of gold restorations are:
The disadvantages with gold restorations are:
Porcelain is made by fusing minerals like feldspar silica and alumina in a glass matrix at high temperatures to form a translucent material that is very tooth like in appearance.
The advantages of porcelain restorations are:
The disadvantages of porcelain restorations are:
Composite fillings are made from a mixture or finely ground quartz and Bis-GMA resin. hey have very tooth-like qualities in both appearance and hardness. They were originally developed for anterior (front) teeth because of their tooth-like appearance, but more recently the amount of quartz filler has been increased and the particle size decreased to give them increased wear resistance for use in posterior (back) teeth. The composite restorations may be fabricated either directly in the mouth (direct), or made in the lab (indirect).
The advantages of direct composites are:
The disadvantages of direct composites are:
Indirect composite fillings are processed in the lab using heat, light and pressure this allows more of the material to be polymerised and the shrinkage to be controlled.
The advantages of indirect composite fillings are:
The ability to measure toxic materials has always been difficult, and their affect on the body almost impossible to determine due to the individuality of each person. When Dr Richardson carried out equivalent tests on composites to those he did on amalgam for the Canada Health 2000 group he found no significant risk in the use of composites. Antibodies are usually produced when toxic elements are introduced to the body. One way of assessing the toxic affect of a material is to measure these antibodies, as carried out in the Clifford Materials Reactivity Test. This test is useful when treating environmentally compromised or highly allergic patients. Applied kinesiology is a well researched technique that we use in the practice to help asses the biocompatability of the various materials we use. It involves testing the body's reaction to a material by using the strength of various muscles as the indicator.
What precautions are taken during silver amalgam filling removal?
When the fillings are drilled out, heat and small particles of filling are produced. Consequently there is a high risk of mercury exposure at these times. This risk can be minimized by taking a few precautions:
Nutrition and Detox
As described earlier in the article, mercury affects the body in different ways. To minimize the metabolic affect of the mercury, specific nutrition can be taken. Minerals and vitamins affect the way in which the mercury is metabolized and taken up by the body. Simply put, vitamins and minerals are either used to make new enzymes to replace the ones destroyed by the mercury, or they attach to the mercury and make it less bio-valuable. This is a very complicated subject, if you wish to know more about it please ask and we can give you more information.
Supplements should be taken before during and after 'silver filling' removal. A typical supplementation regime is outlined below:
Preparatory complexes are available for nutritional supplementation. Please ask at the practice.
There are other therapies available to help with removing mercury from the body:
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