by Seymour L. Gottlieb, BS, BDS, DDS, member of NOHA's Professional Advisory Board, with a private practice in Dentistry in Northbrook, Illinois; former Research Assistant and Instructor, College of Dentistry, University of Illinois and Researcher in Microbiology, United States Public Health Service, Center for Disease Control.

If you are an adult with fillings in your teeth, a good number are probably silver amalgam. These so-called silver (or amalgam) fillings contain about 50 per cent mercury, 33 per cent silver, 12 per cent tin, 3 per cent copper, and 2 per cent zinc. In the early 1830s the amalgam filling was introduced in France and the United States as a cheaper substitute for gold, which was the only filling material used at that time. Until recent years, almost every dentist placed silver-amalgam fillings. According to the American Dental Association, more than 100 million silver-amalgam fillings are placed in American mouths each year. In addition, it is a common practice to leave some of the filling on the tooth even under a crown to add extra support when little tooth structure remains.

---

Until recent years, almost every dentist placed silver-amalgam fillings. According to the American Dental Association, more than 100 million silver-amalgam fillings are placed in American mouths each year.

---

Fillings are in continuous contact with body tissues and fluid. Silver amalgam is not inert in a strict chemical sense. Advances in both equipment and measurement techniques now allow researchers to detect mercury levels within the mouth. It is known that mercury even in extremely small amounts can have toxic effects. Low-dose mercury exposure has been shown to produce neurological, immunological, and endocrine dysfunction. This has led in 1990 to the government of Sweden passing a law requiring the National Health Insurance System to pay part of the cost of replacing silver-amalgam fillings. In February, 1992, the German Ministry of Health banned one form of silver-mercury filling.

The average silver filling weighs one and a half to two grams. The amount of mercury absorbed daily ranges from 1.2 up to several micrograms per day, depending upon the number of fillings present. In their Environmental Health Criteria document released in 1991, the World Health Organization stated that the general population is probably exposed to mercury through diet and dental fillings. They estimated that we get from 3 to 17 micrograms per day from fillings, 2.3 micrograms per day from fish and seafood, 0.3 micrograms from all other foods, and only traces from air and water. Mercury can enter the body either through respiration in the form of mercury vapor from the fillings, be absorbed through tissue around the silver fillings, or be ingested through the stomach. Mercury released from fillings dramatically increases with chewing or heat stimulation and does not return to its baseline low level for 90 minutes. Once mercury is inhaled, 74 to 100 per cent is absorbed from the lungs into the blood stream and into tissues throughout the body. Personal habits such as grinding teeth and mouth breathing further increase the daily exposure. Significant amounts of mercury will accumulate over time because it takes the body 30 to 70 days to eliminate one-half of each exposure, which occurs each time we chew.

---

Symptoms attributed to mercury include any of the following: anxiety, confusion, depression, irritability, sleep disturbances, tension, anemia, pressure in the chest, chronic headaches, tingling of fingers and toes, digestive problems, loss of appetite, chronic low body temperature, weight loss, lack of energy, muscle weakness, immune system debilitation, bad breath, burning sensation and metallic taste in the mouth, purple-black pigments in the gums, and dermatitis.

---

A study conducted in 1990 placed radioactive mercury in the chewing-surface fillings of pregnant sheep. Three days after placement of the fillings, radioactive mercury was found in the maternal blood, urine, and feces, in the amniotic fluid, and in the fetal blood. By 16 days it was found in the maternal kidney, liver, gastrointestinal tract, and thyroid as well as in the pituitary, liver, and kidney of the fetus. By 33 days the fetal tissues had high levels of mercury. The study concluded that mercury vapor released from fillings is readily absorbed in the lung, jaw, and gastrointestinal tract and progresses through the placental membrane to the fetal tissues. During lactation there was eight times more mercury in the milk than in the maternal blood serum.

Problems from mercury can be latent and may take an extended period of time to show an effect on the body. Mercury generally has been found highest in the kidneys, stomach, liver, and brain, indicating deposition in target organs. Symptoms attributed to mercury include any of the following: anxiety, confusion, depression, irritability, sleep disturbances, tension, anemia, pressure in the chest, chronic headaches, tingling of fingers and toes, digestive problems, loss of appetite, chronic low body temperature, weight loss, lack of energy, muscle weakness, immune system debilitation, bad breath, burning sensation and metallic taste in the mouth, purple-black pigments in the gums, and dermatitis.

Tests 

Since mercury travels to target organs, mercury levels in the blood do not show a direct correlation with the appearance of symptoms. However, blood levels and other laboratory tests can be valuable in assessing the effects of mercury, as well as indicating the body's excretion efficiency. When mercury elicits overt symptoms in an individual and the removal of silver amalgams is prescribed, we need to know what materials are suitable for replacement fillings. A new, effective, blood bio-compatability test is available through dentists and physicians, which not only tests an individual's sensitivity to mercury and other toxic metals but also checks the body's compatibility to over 900 dental materials. This is accomplished by an immune challenge, i.e., testing reactivity on the patient's blood serum. There are also electro-acupuncture and kinesiological (muscle testing) methods to aid in determining a person's sensitivity to mercury. Skin patch tests are not often performed due to the additional exposure to mercury and the possibility of further sensitization.

---

The removal of silver-amalgam fillings is not necessarily the answer to all health problems. It is not meant to be a total cure. However, we do know that mercury is one of the many contributing factors to sub-disease processes. 

---

A screening method to detect the release of mercury vapor in the oral cavity can be done with a Jerome analyzer, which measures the amount of mercury vapor released in chewing. This device is used by the Occupational Safety and Health Administration (OSHA) to check mercury vapor levels in industry. OSHA uses a level of about 50 micrograms per cubic meter as their maximum allowance of mercury vapor in the work area. People with several silver fillings can average, after chewing, mercury vapor levels as high as 50 to 150 micrograms per cubic meter. The World Health Organization and the United States Environmental Protection Agency say that no amount of exposure to mercury vapor can be considered totally harmless.

Treatment

Your dentist can be effective in removing silver fillings by use of a heavy stream of air and water as well as a high volume vacuum to trap and remove the particles. Pure oxygen inhalation is used to prevent breathing in the mercury vapor formed while the silver amalgam filling material is being removed. In addition, an elastic protective sheath can be used to isolate the tooth being treated so that particles can be quickly removed without absorption. Excellent ceramic replacement materials, which contain no metal, are now available for restoring teeth.

Some of the things you can do to improve your health status during treatment are to supplement your diet with vitamins, minerals, and fiber. Include anti-oxidants such as vitamins A, C, and E plus selenium and multi-vitamins with minerals including zinc, manganese, and calcium. Homeopathic remedies recommended by your physician or health practitioner should be included.

No single material is suitable for all patients. The individual's ability to handle dental materials can now be verified before treatment. The removal of silver-amalgam fillings is not necessarily the answer to all health problems. It is not meant to be a total cure. However, we do know that mercury is one of the many contributing factors to sub-disease processes. One of the first things to do is to find out if mercury is overtly toxic for you. Evidence indicates that mercury vapor is released and gets into other parts of the body. The only thing we do not know is how little an amount of mercury is needed to cause overt damage. We do know that mercury accumulates in the body and, once it is absorbed, it is excreted slowly over an extended period of time.

_____________

Gilmore, H. et al, Operative Dentistry, C. V. Mosby, 1977.

Vimy, M. and F. Lorscheider, "Serial measurements of intra-oral mercury: estimation of daily dose from dental amalgam," Journal of Dental Research, 64:1072-5, 1985.

Stortebecker, P., Mercury Poisoning From Dental Amalgam, Bio-Probe Inc., Orlando, Florida, 1985.

Taylor, J., Mercury Toxicity From Dental Fillings, Scripps Press, San Diego, California, 1988.

Clarkson, T. W. et al., The Biologic Monitoring of Toxic Metals, Plenum Press, New York, 1988.

Presentations at scientific meetings of the International Academy of Oral Medicine and Toxicology, September, 1990 and May, 1992.

Bland, J., "Primary Therapy for Mercury Detoxification," Informed Consent Bulletin, Environmental Dental Association, 1992.

Olsson, S., "Daily dose calculations from measurements of intra-oral mercury vapor," Journal of Dental Research, 71(2):414-23, February, 1992.

Skare, I., "Amalgam restorations -- an important source of human exposure to mercury and silver," Lakartidningen, 15:1299-1302, 1992.

Aposhian, H. V. et al, "Urinary mercury: correlation with dental amalgam," Federation of American Societies for Experimental Biology, 6(6): 2472-6, April, 1992.