Mercury Toxicity
The Book

"The doctor of the future will give no medicine, but will interest his patients in the care of the human frame, in diet and in the cause and prevention of disease." - Thomas A. Edison

Peter Varley BDSc, FDSRCS, DFHom(Dent.) and Jack Levenson LDSRCS(Edin).(profile)


Given the very large human exposure to mercury, how poisonous is it? The University of Tennessee has a renowned toxicity centre where they grade poisons based upon the least amount necessary to kill a human. Plutonium is the most deadly and is rated on the scale as 1900.

  1. Plutonium   1900
  2. Mercury   1600
  3. Lead   900
  4. Nickel   600

Mercury, except in severe allergic reactions, is not a drop dead poison. It is insidious in its action and accumulates in tissues and organs. This renders diagnosis more difficult. Coupled with the fact that since the use of mercury by physicians has been drastically reduced in therapeutic medicine, the ability to diagnose mercury poisoning has shown a similar decline.

History of Mercury in Medicine

Mercury was used as a medicine in India as early as 500BC. Due to its bactericidal effects it was introduced as a drug by Arab physicians in the tenth century for the treatment of chronic skin disease. The use of mercury in medicine spread to Europe and by the 16th century was widely prescribed as an effective treatment for syphilis.

By the 18th century as mercurial treatment became established in medical practice, so opposition to its use increased. The argument became a major topic for press and public. Doctors were so convinced that mercury cured venereal disease that it was perceived to be a panacea for a variety of ailments.

Mercuric chloride was used as an antibacterial solution in disinfectant. This and other salts were used as purgatives and fungicides, as ointments in treatment of eye and skin diseases and in worm chocolate as treatment for intestinal parasites. Mercury increases urinary flow and found favour as a diuretic.

Today mercury is still used in skin lightening creams. They were banned in Nigeria as the mercury content can cause miscarriage and affect the brain and kidneys. Mercury is in some throat lozenges and is widely used as a fungicide and preservative in vaccines and contact lens sterilising solutions.

History of Mercury in Dentistry

In 1812 Joseph Bell, a British chemist, introduced the forerunner of the modern amalgam filling. This consisted of a paste which was formed by filings from silver coins and mercury, which due to impurities in the coins tended to expand, sometimes resulting in a fractured tooth or an uneven bite.

American Dental Association

Aggressive advertising by some practitioners in New York led to an increase in demand which in turn led to a reaction, which precipitated what has become known as the first amalgam war. The opponents were the American Society of Dental Surgeons (ASDS) founded by Dr C A Harris in 1840.

The society vigorously opposed the use of amalgam and in 1845 they passed a resolution ‘pronouncing the use of all amalgams as malpractice’. So, in effect, dental amalgam was banned for some 15 years. But an increasingly vociferous minority defied the ban. They had found a commercially viable material, inexpensive and easy to use, durable and with no apparent side effects.

Economics won the day. The ASDA collapsed and a new organisation, the American Dental Association (ADA) was founded to support the argument that mercury was locked into fillings and could not escape. Dentists found this easy to believe, conscience and commerce were satisfied.

Chemistry and Mechanism of Action

Mercury has a high affinity for sulphydryl (thiol) groups. Mercurials, even in low concentrations are capable of inactivating sulphydryl groups present in biologically active agents. These include proteins, enzymes and enzyme inhibitors, and allow mercurials to interfere with cellular metabolism. The binding with various groups results in cell membrane permeability, poor cellular nutrition and interference with enzyme reactions in the cell.

In the lungs mercury vapour tends to oxidise into free radicals i.e. mercury ions. These ions are an electrically charged form of the element and will react quickly with Haemoglobin, Insulin, Thyroxin, Co-Enzyme A

When it reacts with haemoglobin the result is chronic fatigue. When it reacts with insulin, the pancreas is stressed. When it binds to Co-enzyme A, which converts food to blood sugar, the result is hypo-glycaemia.

Dental Galvanism

The presence of different metals in the same tooth, or in different teeth, acts as a battery, producing an electric current with saliva as an electrolyte. This current with its attendant electromagnetic fields is inches from the brain and cranial nerves and can influence a variety of disorders e.g. Bell’s Palsy, Migraine, Trigeminal Neuralgia, Neuromuscular Pathologies (MS) and Epilepsy.


Bacterial Resistance

A strong correlation between mercury and multiple antibiotic-resistant intestinal bacteria had been observed by researcher Anne Summers in 1981. At that time it was not linked to dentistry as it was believed that mercury could not be released from fillings. Mercury-resistant bacteria recirculate mercury as vapour and block elimination. Antibiotic-resistant bacteria - the super bugs - are a serious escalating problem. It is time the possible causes are reconsidered.

Mercury and the Central Nervous System

Nylander has demonstrated surprisingly high post mortem concentrations in the pituitary glands of dentists, out of all proportion to other areas of the brain. Stortbecker explains, ‘this is because the pituitary has an extra dose by direct transport from the nasal cavity’.

Mercury and Multiple Sclerosis(MS)

The Swiss neurologist Basch hypothesised that MS is a neuro allergic ailment, the allergen being a heavy metal, probably mercury. Britt Ahlsot-Westerland showed that mercury levels in the cerebo-spinal fluid (CSF) of MS patients was 7-8 times higher than the controls, both groups having similar amounts of amalgam filling.

Mercury and Parkinson’s Disease

Subjects with Parkinson’s disease had significantly higher mean levels of mercury than controls.

Mercury and Motor Neurone Disease

Motor Neurone Disease is a chronic neuro-degenerative disease also known as Amyotrophic Lateral Sclerosis (ALS). Brown reported 6 cases of ALS in farmers dusting seeds with methyl mercury. In the Iraq disaster large groups of patients demonstrated neurological conditions similar to ALS.

Mercury and Alzheimer’s Disease

In a recent study on the brains of Alzeimher’s Disease (AD) autopsied cases, concentrations of trace elements were measured. They consistently found the highest trace element to be mercury. In comparison with age matched controls, the mercury content was found to be significantly higher. The mercury concentration was found in areas of the brain associated with memory.

Mercury and Infertility

This work was carried out at The Department of Gynaecology, University of Heidelberg. The chelating agent for mercury, DMPS, was given to women with hormonal irregularities, to remove mercury from the body. Since recognising and treating the environmental contamination burdens of the women 70% became pregnant without the use of hormonal therapy.

Safety of Dental Amalgam

No research has ever been produced to demonstrate the safety of amalgam fillings. No long term studies have ever been carried out. There have been a number of reviews of published research papers, with questionable conclusions.

The latest comprehensive review was published by the British Dental Association in 1993 in which it was suggested that there was a need for further research 63.

World Reaction to Mercury Fillings


The government concluded in 1987 that mercury fillings were unsuitable from a toxicological point of view. On 18th February, 1994 the Swedish Ministry of Health announced in a press release that the use of amalgam would be totally banned for children and adolescents up to age 19 by 1st July 1995 and for adults by 1997.


In 1992 the German Ministry of Health, inspired by the Drasch paper issued a pamphlet recommending that amalgam should be avoided for the following people.


The Austrian Minister of Health announced that the use of mercury fillings in children would be banned in 1996 and discontinued for all Austrians by the year 2000.

World Health Organisation

In a document on environmental mercury, their determinations regarding human daily retained intake of mercury from various sources are:

The committee also noted that ‘a specific No-Observed-Effect Level( NOEL) cannot be established’, meaning that no level of exposure to mercury vapour that can be considered harmless has been found.

Mercury and the Dentist

Mercury Regulations

Few people are aware of the stringent recommendations of Mercury Hygiene as documented by the Council on Dental Materials and Devices.

The above recommendations provoked the comment from one dentist, ‘It would seem that the only safe place for mercury is in the patient’s mouth’. The degree of exposure to mercury would vary in different surgeries, however it would seem from from the literature that both dentists and their personnel are at risk.

Removal of Amalgam Fillings

Fillings should be removed in a predetermined sequence depending on electrical readings. Quadrants having the highest reading should be removed first. This is important when there are high differentials.

Priority Order for Amalgam Removal

  1. Root canal-treated teeth with pins or screw-posts of non-precious metals and metal crowns with amalgam cores should be treated first
  2. Next are amalgams in direct constant contact with gold. Often the amalgam can be removed while the gold inlays, the crown or the bridge, can be left. What to do with the gold can be decided later.
  3. Where there is direct intermittent biting contact between amalgam and gold in opposing teeth.
  4. Where there is direct contact between amalgam and other metals like partial chromium-cobalt dentures.
  5. Other teeth with root canal fillings of N2 and gutta-percha. The latter often contains cadmium. The filling materials and sealers generally contain an amazing array of highly toxic compounds.
  6. Retrograde amalgam fillings must be removed. These fillings can be seen on x-rays at the root apex.
  7. Most patients have several different types of amalgam fillings, and the ones containing the newer types of amalgam high in copper (non-gamma 2 amalgam) should be removed first. The priority order between different fillings can be based on the patient’s own opinions or visible signs of corrosion and discoloration.
  8. Amalgam fillings in contact with gum tissue. It might be necessary to remove metal-impregnated gum tissue surgically.

Pre-treatment Plan

Protection of the Patient During Amalgam Removal

The surgery should have good ventilation and an efficient filtration system. Where possible, rubber dam should be used in conjunction with efficient high-volume evacuation to protect the patient from the aerosol of water coolant spray used with the high speed cutting (see diagram). When drilling, the filling should be sectioned into chunks and elevated where possible. If any metal has been used as a restorative material, then all amalgams should be removed first. Patients should wear clothes covering as much skin as possible.

For sensitive patients, when drilling out amalgam cover the eyes with wrap around goggles and use an RA nosepiece with tubing attached to extend out of operating area to protect against nose inhalation of mercury vapour. Some practitioners use oxygen flow.

Scheduling of appointments depends very much on the reaction of the patient after the first treatment. Patients should be monitored and supplementation varied as necessary.


Post-Treatment Protocols

Continue supplements for 2-3 months. Warm baths, low-heat saunas, acupuncture, massage, counselling and healing have all proved useful. Any remaining Candida, food allergies and digestive disorders usually become more amenable to treatment.


Mercury is the only cumulative vaporising poison permanently implanted in the human body

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