Heavy Metal: Fifth in our dental series in which alternatives takes a look into the yawning american mouth
They Don’t Still Put Mercury in Dental Fillings, Do They? Part 2
by Sandra Duffy
Evidence of Harm
“I think that amalgam as soon as possible should be banned in the whole European Union. Every medical doctor and dentist should consider whether mercury from amalgam could be a contributing factor when they meet patients with unclear diseases and diseases which involve the immune system.”
— Dr. Mats Berlin, World Health Organization’s leading expert on mercury toxicity
What is the evidence that supports the ADA claim of safety for amalgam or the mercury-free activists’ claim of health harm? The ADA states: The strongest and most convincing support we have for the safety of dental amalgam is the fact that each year more than 100 million amalgam fillings are placed in the United States. And since amalgam has been used for more than 150 years, literally billions of amalgam fillings have been successfully used to restore decayed teeth.
Thus, the ADA’s proof of safety is its assertion that because amalgam works to restore teeth, it is safe.
As of April 2006, the ADA additionally points to an $11 million National Institute of Dental and Craniofacial Research (NIDCR) study that compared the adverse health effects of amalgam fillings in children, with adverse health effects in child-subjects who received non-amalgam fillings. One branch of the study was conducted with 500 low income children from New England and the other branch with 500 children attending Casa Pia schools in Lisbon, Portugal.
These studies, known as the Children’s Amalgam Trials (CAT), were published in the April 19, 2006 issue of the Journal of the American Medial Association (JAMA). The trial investigators concluded that there were no significant differences in the target health measures between the subjects with amalgams and those without.
These studies are controversial. The federal Office of Human Research Protection is conducting an investigation looking at the adequacy of the Informed Consent forms, which did not disclose to the Casa Pia guardians that amalgam contains mercury; the impact, if any, of the sex abuse scandal at the Casa Pia schools that lasted three decades and was discovered during the pendency of the trials; and, issues related to bias and conflicts of interest of the researchers. Other researchers are seeking the data compiled by the University of Washington researchers, who conducted the Casa Pia trial for further evaluation.
In the same issue of JAMA, an editorial by Herb Needleman, MD, was published, commenting on the CAT, and urging caution against reading too much into the studies. He mentions that the trials were too short to assess the long-term effects of the children’s exposure to the neurotoxic mercury. The New England branch of the studies was a five year study and the Casa Pia branch was a 7 year study. Dr. Needleman points out the weaknesses and limits of the studies and warns that: With the application of better epidemiological designs and more robust statistical methods to investigate toxicity, the usual consequence is uncovering effects at lower thresholds. The trajectory of discovery of … lead has followed this path … and may offer insight into the future path that mercury investigations may follow.
Twenty years ago Dr. Needleman was on the forefront of the warnings on lead thresholds, warning that the so-called safe levels were set much too high. It is now understood that there is no safe level of lead exposure for the developing brain.
One peer reviewed study by H.L. Schubert, published in the Journal of Toxicology and Environmental Health in 1978, tested the relative amounts of lead and mercury which would kill 1% of rat subjects. The amount of lead resulting in a 1% lethal dose (LD) was 280 micrograms of lead per kilogram of body weight. And for mercury it was 7 micrograms of mercury per kilogram of body weight, i.e. 1/40th as much. But what was revolutionary in this study was that the synergism of the two neurotoxins were tested and it was found that a combination of 280 mcg pb/kg (1LD) added to 7 mcg hg/kg (1LD) killed 100% of the rats (100 LD). This is synergistic toxicity which makes it impossible to define a “safe” level of mercury.
In 2002, Kazantzis looked at 40 years of peer-reviewed literature to determine whether there was any safe level of mercury exposure. He concluded: As mercury can give rise to allergic and immunotoxic reactions which may be genetically regulated, in the absence of adequate dose-response studies for immunologically sensitive individuals, it has not been possible to set a level for mercury in blood or urine below which mercury related symptoms will not occur.
Dr. Needleman, in his JAMA editorial, indicated that he also understands the political use of studies like the CAT. He states: It is predictable that some outside interests will expand the modest conclusions of these studies to assert that the use of mercury amalgam is risk free. This conclusion would be unfortunate and unscientific.
In fact, the ADA has made such an assertion and has waged a nationwide public relations campaign to continue to mislead the public on this issue. The title of an article on the ADA’s website says it all: “Two New Clinical Studies Support the Safety and Use of Dental Amalgam in Children.”
In contrast, mercury-free dentistry activists point to thousands of peer-reviewed scientific journal articles, some of which conclude that mercury vapor is not inert, it is emitted from amalgams in excess of government safety limits; that 80% of it is absorbed into the lungs; that certain subsets of the population with certain genetic markers are more vulnerable to harmful effects; that the harm includes, among many other types of harm, measurable neurological and neurobehavioral deficits; that specific health harm to dentists and dental personnel have been linked to their exposure to amalgam; and, that safe removal of amalgam with biological detoxification resulted in significant improvement of adverse health conditions.
Mercury-Free Denistry Movement
The use of mercury amalgam in back teeth (molars) is considered the “standard of care” by the ADA, its constituent state dental associations, state dental boards and dental insurance reviewers. All American and Canadian dental schools must teach the placement of amalgam fillings as part of their curriculum. The ADA, through an alter ego, the American Dental Education Association, which is headquartered with K Street lobbyists in Washington D.C., accredits all dental schools. This is an educational monopoly structured to support the continued use of mercury in dental fillings.
However, for decades, some dentists have been making a decision to practice dentistry without using mercury. They say they do it for the safety of their patients, their staff and themselves. In the early days of mercury-free practice it was challenging to find satisfactory alternative materials for back teeth. There are now many safe and effective alternatives to mercury amalgam. According to the Christensen Research Institute, the number of dentists with a mercury-free practice was 3% in 1985; it tripled to 9% in 1995; and, more than tripled again to 28% in 2001. It is estimated that mercury-free dentists are now one-third of practicing dentists.
The ADA points to the poor characteristics of non-mercury fillings and claims that amalgam is the only material that can be used for some applications. The ADA also asserts that the alternatives do not last as long, have to be replaced more often and are more expensive because they take more time to place. However, metal fillings expand more than the alternatives and can crack teeth leading to crowns, root canals, and loss of teeth, jawbone infections and periodontal disease. Even the California Dental Association will admit that use of amalgam results in the removal of healthy tooth structure to accommodate the filling.
Other countries have faced the controversy over the use of mercury amalgam dental fillings and many of them have taken some kind of action to limit their use. Some examples include: Health Canada (Canada’s FDA equivalent) has advised that children 6 and under, and pregnant women not receive amalgams. Sweden does not reimburse the cost of placing amalgams. In 2002, Mats Berlin, formerly the World Health Organization’s leading expert on mercury toxicity, was given the task of evaluating dental amalgam. On April 25, 2003, a report was published and concluded that amalgam hazards were being underestimated. Dr. Berlin, in speaking about the report stated: I think that amalgam as soon as possible should be banned in the whole European Union. Every medical doctor and dentist should consider whether mercury from amalgam could be a contributing factor when they meet patients with unclear diseases and diseases which involve the immune system.
Norway advises that all alternatives to amalgam be considered first. Japan has stopped teaching the placement of amalgams in its dental schools. The U.S. stands out for its failure to have any federal limits at all on the use of amalgams. Characteristically, the ADA is urging the FDA to classify amalgam as a medical/dental device (safe with labeling that warns of its zinc content, but not its mercury content) and to preempt all state law limitations on amalgam.
Strategies to Abolish the Use of Amalgam
The term “mercury-free dentistry activists” refers to individuals, including those who have been harmed by mercury amalgam, environmental groups that support efforts to keep mercury out of the environment, Dental Amalgam Mercury Syndrome, Inc, (DAMS), a support group for mercury-poisoned dental consumers, mercury-free dental associations and Consumers for Dental Choice, a national tax-exempt non-profit established in 1996 by consumer advocates, which is headquartered in Washington D.C.
Consumers for Dental Choice is lead by Charles G. Brown, former state Attorney General of West Virginia, and its goal is to ban the use of mercury in dentistry, to create a fair playing field for mercury-free dentists and to educate the public about the health hazards of amalgam. Mr. Brown is conducting a national campaign to expose the deceptive practices of the American Dental Association (ADA) and state dental organizations and the illegal refusal of the FDA to regulate mercury amalgam. He is also legal counsel for the Coalition to Abolish Mercury Dental Fillings, the lobbying arm of the movement.
Since the organization began, the number of amalgams placed has declined dramatically, from two-thirds of all fillings placed to one-third, and the number of mercury-free dentists has grown dramatically, but abolition of mercury in dentistry remains its primary goal. The methods to accomplish this goal include:
(1) educating consumers and legislators on federal and state legislation that requires dentists to obtain informed consent from dental consumers, institutes immediate bans on use of amalgam in vulnerable populations and, ultimately, completes the ban on mercury-based fillings for all others;
(2) educating consumers, legislators, health officials and the media to promote the full disclosure of the risks associated with mercury amalgam fillings, to encourage the free flow of non-deceptive information between dentists and patients, which includes efforts to end the American Dental Association’s notorious “gag rule” which tries to silence mercury-free dentists;
(3) monitoring research relied upon by federal agencies to be certain that it is based on sound science and engaging experts to counter studies by non-independent or unqualified researchers that urge continuation of amalgam for spurious reasons such as “it’s good because we’ve used it for 150 years,” or “a mixture of amalgam is similar to the combining of sodium and chloride to make table salt;”
(4) educating, petitioning and filing lawsuits against the FDA to urge it to fulfill its statutory duty to protect consumers from the harmful effects of amalgam, an unapproved dental device;
(5) recruiting and promoting mercury-free dentists as nominees for appointment to the state dental boards of the individual states;
(6) supporting and defending mercury-free dentists who are targeted by state dental boards for the purpose of suppressing competition; and
(7) filing lawsuits to enforce laws regulating mercury and/or mercury amalgam which are not being enforced.
The disconnect between the facts and journalistic accuracy on the issue of mercury amalgams exists because the ADA is considered the authoritative source on all things dental. Many writers do not fact check the ADA. The best evidence of the success of ADA’s tactics is the 170 years of continual use of dental amalgam.
The Choice of JAMA for publication of the CAT reports may continue to mislead medical doctors into thinking that mercury in dental fillings cannot be considered a source of adverse health conditions; their colleagues over a hundred years ago were more aware of the toxicity of amalgam. The CAT studies were conducted to protect the economic interests of dentists, not to test the safety of a beneficial dental device, for which many excellent alternatives already exist. The controversial studies and the controversial results are just the most recent volley in a 170 year battle to convince the public that a known neurotoxin isn’t toxic. But an industry that depends for its livelihood on an embargo of legally and morally required consumer information does not have a bright future in the Information Age.
The Precautionary Principle clearly steers consumers away from mercury dental products, including amalgam, because safer alternatives are available and eliminates an unacceptable risk to human health and to the environment.
Sandra Duffy, J.D. is Board President of Consumers for Dental Choice. She lives in Lake Oswego, Oregon, and may be contacted at [email protected].