Mercury in the environment comes in 3 forms, methyl mercury (organic mercury), inorganic mercury (aka mercuric salts) and elemental mercury. Dental amalgam is a combination of metals; 50% elemental mercury, with the balance being comprised of silver, tin, copper and a trace amount of zinc.
There has been controversy over the use of mercury in dental fillings ever since 1826, when a Parisian dentist combined it with silver, copper and other metals to form a paste. Seven years later, two brothers in New York city (with no dental experience) began to promote mercury as a cheap alternative to gold fillings. By the end of the 1830s, the use of mercury amalgam was common place in the United States, as not only was it cheap and strong, it took less time and skill to put them in than gold fillings. Dentists of the time were appalled by the thought of using a known poison in the body of there patients, and in the 1840s the American Society of Dental Surgeons required its members to sign a waiver to not use it in their practices. Many dentists refused to sign because they believed mercury's low cost would benefit the poor and themselves. The debate caused such a schism in dentistry that the Society eventually folded, leaving the door open for the formation of the American Dental Association (ADA) in 1859, who immediately defended the use of mercury containing amalgam, helping to establish it as a popular dental filling by the end of the 1800s (Null & Feldman 2002).
Despite numerous studies that have shown amalgam fillings are not stable or safe, and that mercury vapors are released, with Vimy & Lorscheider (1985) stating “the amount of elemental mercury released from dental amalgam exceeds a major percentage of internationally accepted threshold limit values for environmental mercury exposure. This confirms previous studies carried out by Svare et al (1981), who observed that the mercury content in the expired air of 40 people with amalgams was 15.6 times higher after chewing than that of the controls, whose readings remained unchanged. In 1996, Gebel & Dunkelberg found that amalgam carriers who chewed gum had urinary mercury levels twice that of controls with a similar mercury burden who didn't chew gum, this showing that the more gum you chew, the more mercury vapour is released.
"The ADA claims that when mixed with other metals the amalgam fillings form a biologically inactive substance," said Dr. Tano Lucero (a former research chemist and industrial hygienist for OSHA who later became president of Bio-Ethics Medical Center in Scottsdale, Arizona), during an interview with Gary Null (Null & Feldman 2002). "This is simply not true. Is elemental mercury escaping from filling material? The answer is an absolute YES!... Having worked for OSHA for 17 years, never have I witnessed anything of the magnitude of resistance in acknowledging the danger of toxicity in silver amalgams as by the ADA."
Blaylock disputes this, stating “a number of studies have shown blood levels and oral levels of mercury are substantially higher when chewing ordinary gum and even a piece of rubber tubing. Hot liquids or foods also have been proven to substantially raise oral mercury vapor levels as well as blood levels”. According to Patterson et al (1985), even the simple act of brushing the teeth can cause mercury vapors to be released from amalgam fillings.
A replacement material for amalgam fillings was discovered, a material known as composite resin, containing Bisphenol A, a chemical which has been found to mimic hormones in the body. It is suspected that these xenoestrogens, which are also present in plastic food wrap, food cans, and plastic food containers can be harmful in small amounts. Olea (1999) and Steinmetz (1998)
It was once said that the danger of mercury leaking from amalgam fillings was not viable, that the mercury used in fillings is inorganic, so is not absorbed by the human body, unlike the organic mercury (methyl mercury) that is found in fish (Preston (2005). The assumption that the mercury used in amalgams is inorganic is incorrect (it is elemental mercury), as is the conviction that the non organic mercury can do no harm due to its chemical nature. It has been known since 1975 that organisms of the mouth and intestines can convert elemental mercury into methylmercury (Peaker & Linzell 1975), which can then be absorbed in the gastrointestinal system. The vapor of elemental mercury is also absorbed rapidly and easily through the lungs where it is distributed throughout the human body crossing both the placenta and blood brain barrier (EPA 1997).
Osborne & Albino (1999) Dentists are among the victims of mercury poisoning, a 10 year study showed, that dentists have the highest suicide rates amongst all college educated professionals, concluding that the mental health consequences of mercury exposure among dentists should be investigated further. Related studies indicate that dentists may be more vulnerable to stress and consequent depression than members of other professions (Shurtz et al 1986), and a study of dentists in private practice in South Africa found that 10 percent had suicidal thoughts. Moller & Spangenberg (1996)
In 1995, a study documented the behavioral effects of low-level mercury exposure on dentists working with amalgam, revealing significant defects, including poor mental concentration, emotional lability and mood problems in the mercury-exposed dentists compared with a control group of non-amalgam dentists (Echeverria et al 1995). A follow-up cross-study was carried out by Bittner et al (1998), which found that long-term exposure to amalgam can make dentists' hands unsteady, which can affect their manual dexterity. Researchers found remarkable differences in psychomotor performance between the amalgam and non-amalgam dentists.
Before deciding to replace amalgam please consult you dr or dentist to ensure the health implications and consider seeing a naturopath to support you on the decision you make.
Blaycock (2005) genetics play a part in reducing a persons susceptibility to the effects of mercury. He also states that selenium has been shown to significantly lower brain mercury levels and reduce its toxicity.
Balch (2000), recommends the use of Vitamin E, in the form of d-alpha-tocopherol, as it works with selenium to neutralize mercury within the body.
Clark (1997) recommends supplementing with glutathione, as studies have shown that mercury by-products resulting from amalgam corrosion are 50 times as toxic to the same cell cultures when glutathione is removed.
The ADA’s defence of mercury in dental amalgams is:
"When mercury is combined with the metals used in dental amalgam, its toxic properties are made harmless." (ADA 1984)
“Mercury in dental fillings is combined with silver and copper, and is transformed into a stable metal material that is not easily released into the oral cavity. Therefore, it is not harmful." what do you think?
“only chewing nicotine gum significantly increases mercury vapor release in the mouth.”
“amalgam does release small amounts of mercury, but this evaporation stops as soon as the filling is coated by saliva.” (ADA's Guide to Dental Materials and Devices) Sound right?
Now i don't know about you, but maybe its a good time to investigate your shiny silver things in your month a little further. How is your memory? coordination? do you sleep well at night? does your skin itch? feeling stress and don't know why?
Now might be a time to book a consultation with your naturopath and get to the root cause of your ill health.
Bittner AC, Echeverria D, Woods JS, et al: Behavioral effects of low-level exposure to Hg0 among dental professionals: a cross-study evaluation of psychomotor effects. Neurotoxicol Teratol, 1998 Jul-Aug; 20(4): 429-39.
Blaycock, R. (M.D.) 2005. Lies, Damn Lies and Statistics About Mercury
Clark, J. 1997 Chronic Mercury Poisoning – a Nutritional Review
Vimy MJ, Lorscheider FL: Serial measurements of intra-oral air mercury: estimation of daily dose from dental amalgam. J Dent Res, 1985 Aug; 64(8): 1072-5.
Echeverria D, Heyer NJ, Martin MD, et al: Behavioral effects of low-level exposure to Hg0 among dentists. Neurotoxicol Teratol, 1995 Mar-Apr; 17(2): 161-8.
EPA (United States Environemntal Protection Agency) 1997. Mercury Study Report to Congress : Health Effects of Mercury and Mercury Compounds.
Gebel T, Dunkelberg H: Influence of chewing gum consumption and dental contact of amalgam fillings to different metal restorations on urine mercury content. Zentralbl Hyg Umweltmed, 1996 Nov; 199(1): 69-75.
International Academy of Oral Medicine and Toxicology (IAOMT). 2005
Moller AT, Spangenberg JJ: Stress and coping amongst South African dentists in private practice. J Dent Assoc S Afr, 1996 Jun; 51(6): 347-57.
Motorkina AV, Barer GM, Volozhin AI: Patterns of mercury release from amalgam fillings into the oral cavity. Stomatologiia (Mosk), 1997; 76(4): 9-11.
Null, G. (Ph.D.) and and Feldman, M. (M.D) 2002. Mercury Dental Amalgams Analyzing the Debate
Olea, N. 1999. Comments on "Estrogenicity of resin-based composites and sealants used in dentistry": Response. Environmental Health Perspectives 107, pA290-A292.
Osborne JW, Albino JE: Psychological and medical effects of mercury intake from dental amalgam. A status report for the American Journal of Dentistry. Am J Dent, 1999 Jun; 12(3): 151-6.
Patterson JE, et al: Mercury in human breath from dental amalgam. Bull Environ Contam Toxicol, 1985 Apr; 34(4): 459-68
Peaker M, Linzell JL: Biosynthesis and degradation of methylmercury in human feces. Nature, 1975 Feb 6; 462-4.
Preston, D. 2005. Former dental nurse of 16 years.
Shurtz JD, Mayhew RB, Cayton TG: Depression. Recognition and control. Dent Clin North Am, 1986 Oct; 30(4 Suppl): S55-65
Statement by Congresswoman Diane Watson (D-Los Angeles) Mercury in Dental Filling Disclosure and Prohibition Act Los Angeles, California November 5, 2001
Steinmetz, R., Mitchner, N. A., Grant, A., Allen, D. L., Bigsby, R. M. and Ben-Jonathan, N. 1998. The xenoestrogen bisphenol a induces growth, differentiation, and c-fos gene expression in the female reproductive tract. Endocrin. 139: 2741-2747.
Svare CW, Peterson LC, Reinhardt JW, et al: The effect of dental amalgams on mercury levels in expired air. J Dent Res, 1981; 60: 1668-71.
The Superior Court of the State of California Case No. 718228, Demurrer (October 22, 1992).
Ziff and Ziff, Dentistry Without Mercury, p. 17, citing Stortebecker P: Mercury poisoning from dental amalgam — a hazard to human brain. 1985; 32-43.