Amanda Just of Waterford will finally be able to speak directly to federal regulators looking into the health effects of mercury in dental fillings.

Just, who claims to have been made ill by mercury released during a botched dental procedure several years ago, has been cleared to speak for four minutes before a U.S. Food and Drug Administration panel this week in Gaithersburg, Md.

She doesn't intend to mince words.

"I have faith that FDA will act upon the overwhelming scientific evidence and public testimony that children, pregnant women and women of child-bearing age need to be protected from having a known poison placed in their mouths during routine dental procedures," she said in an e-mail.

More than a third of all Americans carry a potential silent time bomb in their mouths, according to two new reports warning about the mercury content in amalgam fillings.

The reports, released over the past few weeks by the International Academy of Oral Medicine and Toxicology, say that so-called "silver" fillings - which actually are 50 percent mercury - represent a potential health hazard to as many as 122.3 million Americans who are exposed to mercury vapor "continually emitted" from standard dental work.

Among the potential outcomes of mercury exposure, according to one of the academy-backed studies, is an increased likelihood of developing Alzheimer's disease, a life-shortening illness afflicting more than 5 million Americans and costing the economy some $172 billion in health bills annually.

"The removal of inorganic (often vaporized) mercury from ecological cycles might prove to be the easiest and most effective public health measure to contribute to the prevention of Alzheimer's disease," concluded researcher Dr. Harald Walach of the Viadrina European University, in a statement.

The two new studies were released ahead of hearings Tuesday and Wednesday by the FDA at which the academy of oral medicine plans to ask the regulatory agency to reconsider its position supporting the use of mercury in fillings.

The oral-medicine group, which filed petitions requesting a review of last year's FDA decision proclaiming amalgam fillings safe, claims that both governmental agencies and the American Dental Association "have been negligent in providing the public with accurate, truthful, up-to-date information about the potential health hazards of mercury vapor from dental amalgam fillings."

Complaints lodged

The academy and another group, Consumers for Dental Choice, are among those that have lodged official complaints about the role of FDA Commissioner Margaret Hamburg, a former director for the dental amalgam firm Henry Schein Inc., who divested herself of the company's stock just one day before the agency's ruling on mercury in fillings.

The international academy said documents it has uncovered through freedom-of-information requests show that the FDA has received more than 3,000 reports of adverse reactions to amalgam fillings in the past two decades. The organization claims that the agency has not investigated the complaints or posted any information about them on the FDA website.

The FDA acknowledges that amalgam fillings release small amounts of mercury vapor, but says on its website that the quantities are "below or approximately equivalent" to the maximum exposure levels seen as safe by government agencies.

"FDA has concluded that exposures to mercury vapor from dental amalgam do not put individuals age six and older at risk for mercury-associated adverse health effects," the FDA says. "FDA has concluded that the existing data support a finding that infants are not at risk for adverse health effects from the breast milk of women exposed to mercury vapors from dental amalgam."

Fillings defended

The ADA maintains that amalgam fillings are safe.

"Some concern has been raised because of (amalgam's) mercury content," the ADA acknowledges on its website. "However, the mercury in amalgam combines with other metals to render it stable and safe for use in filling teeth."

According to anti-mercury advocates, nothing could be further from the truth.

Dr. Boyd Haley, a former chairman of the University of Kentucky's chemistry department who has researched the links between mercury exposure and Alzheimer's disease, noted that the World Health Organization reported in 1991 that amalgam fillings were the greatest contribution of mercury load on the body - much higher than seafood products, such as swordfish and tuna, which are often cited by health authorities as possible high-risk food sources.

The body has a difficult time ridding itself of mercury, so even small exposures to the heavy metal have a cumulative effect on humans' tissue, according to the new reports. The brain is particularly vulnerable to mercury, according to an article this month in The Journal of Alzheimer's Disease, titled "Does Inorganic Mercury Play a Role in Alzheimer's Disease," by German researcher Dr. Joachim Mutter and Dr. Richard Deth of Northeastern University in Boston.

The article takes a systematic look at the scientific literature to conclude that "mercury is likely to be one of the multiple causes of Alzheimer's." It goes on to say, according to a summary of the findings, that "animal and cell models reproduce all the features of Alzheimer's disease when mercury is given."

Not everyone with dental amalgam fillings develops Alzheimer's, the article noted, because some people appear to have natural defenses against the effects of mercury, or have habits that mitigate against excessive exposure.

"A genetic predisposition and exposure to a neurotoxin such as mercury have to co-exist for Alzheimer's disease to manifest itself," according to a summary of the findings.

Mercury in fillings banned in three countries

The second study released by the international academy, a risk assessment written by G. Mark Richardson of the well-known Canadian engineering and environmental firm SNC-Lavalin, concluded that millions of Americans are being exposed to levels of mercury vapor higher than the strict level established two years ago by the California Environmental Protection Agency as well as the looser federal standard set more than a decade ago.

"Placing a poison in the body should be outlawed in dentistry and medicine," concluded Matthew Young, a dentist and president of the international academy, in a statement.

Mercury in fillings already has been banned in Denmark, Norway and Sweden.

In the long run, anti-mercury advocate Just is hoping that amalgam can be replaced with a safer material.

"Although the price already has been paid by the American public, these recent studies open new doors to medical practices that offer millions of people dental alternatives that are so much healthier than amalgam fillings," she said.