Aug. 13, 2001 -- Anita Vazquez Tibau always considered herself healthy. A dance major in college, she was fit and rarely sick. But in her early 20s, while vacationing with her husband, she suffered the first of many asthma attacks that would plague her over the next 20 years.

"Simply staying alive became a major ordeal," says Tibau, 42, of Newport Beach, Calif. "I couldn't breathe, I couldn't walk, I couldn't do anything. I was using my inhaler like every half hour."

Other health problems followed.

Then last year a blood test showed she was highly reactive to mercury. After doing some research, Tibau decided to have the fillings in her teeth -- all 13 of them -- removed, believing the mercury in them had made her ill.

Over the next several months her breathing "improved dramatically," she says. Now more than a year later, she no longer uses any asthma medications and reports an improvement in her energy level and attention span.

Tibau, who became an activist against dental mercury following her experience, is just one of a growing number of consumers, scientists, and others who are warning the public about what they believe is a serious health hazard.

What's Really in Your Mouth?

According to the American Dental Association, or ADA, up to 76% of dentists use silver fillings when filling a cavity. Although the substance that makes up silver fillings, known as dental amalgam, has been used safely for 150 years, the ADA says, some research has suggested the fillings may cause health problems that range from chronic fatigue-like symptoms to neurological problems, including Alzheimer's disease.

So-called 'silver fillings' are a mixture of silver and other metals dissolved with mercury. There are numerous alternatives to silver fillings, including tooth-colored resin, porcelain, and gold fillings -- all of which are considerably more expensive. Some dentists say colleagues who encourage patients to have silver fillings removed and replaced with the more expensive fillings are simply out to make money off the controversy.

The ADA insists once the filling is placed in the tooth, exposure to mercury is minimal, and that numerous studies have failed to find a link between silver fillings and any medical disorder. They do acknowledge, however, that a small subset of people -- fewer than 100 reported cases -- have an allergy to the metal component in the fillings and will have a reaction.

But the ant-mercury camp says the ADA has no proof to back up their claims that mercury is harmless. They also point to the fact that amalgam has never even been tested for safety by the FDA, having been instead ''grandfathered" in because it had been in use for so many years and was assumed to be safe.

Controversy Goes to Court

In June, a group called Consumers for Dental Choice sued the ADA and the California Dental Association, saying the organizations have deceived consumers by using the term "silver fillings" to avoid acknowledging that about half of the filling is mercury.

"Their brochures and patient material all call it 'silver' and that's misleading," says the groups' attorney, Charles G. Brown of Washington.

"Inside the brochures they start talking about mercury and when they do, they compare it to pollen and dust," he says. "They're calling [mercury] something it's not, and they're hiding the fact that they have an economic interest in amalgam."

In a prepared statement given to WebMD, the ADA says the complaint is "without merit" because the organization has never tried to hide the fact that silver fillings contain mercury. The organization also maintains that when the mercury combines with other components of the fillings it becomes an inactive substance.

But scientists like Boyd E. Haley, professor and chairman of the department of chemistry at the University of Kentucky, say there is no proof that this is true.

"They place this stuff in people's mouths and it's toxic before it goes in, and it's toxic when it is placed in your tooth, so how does it suddenly become safe?" says Haley, who has testified before Congress on the dangers of dental mercury.

The only way to limit the amount of mercury released from your teeth if you have silver fillings is not to use them, says Haley. Just brushing lightly with a toothbrush is enough to register a reading on a mercury vapor detector, he says.

Does Lawsuit Prey on Fears?

The ADA says one potential danger of the lawsuit is that it "may prey on the fears of people who have serious medical conditions by leading them to believe that costly dental treatment not based on proven scientific evidence is a cure for such conditions." In other words, the association fears unscrupulous dentists will convince patients to have their fillings replaced with the more expensive substances on the theory that their health will improve or that they can prevent illnesses by avoiding mercury fillings.

"There have been a number of studies looking at the potential effects of mercury from amalgam in the general population, and the preponderance of evidence is that there is no relationship between the presence of amalgam fillings and any disease condition," says ADA spokesperson J. Rodway Mackert, PhD.

"Therefore there's no reason for a patient to avoid placement of amalgam fillings and there's no reason to have amalgam fillings removed for the purpose of trying to alleviate any disease condition," says Mackert, a professor at the Medical College of Georgia, in Augusta.

The Vapor Trail

Several dentists who use mercury fillings in their practices acknowledged to WebMD that they know some mercury vapor does escape from filled teeth during simple everyday activities such as eating, drinking hot beverages, and brushing your teeth, but say they don't usually talk to patients about it because they don't believe the small amounts that escape are harmful.

A number of "mercury-free" dentists feel quite differently.

In a separate lawsuit, attorney Brown is representing five such dentists who are suing the Maryland state dental board, charging that its gag rules keep dentists from being able to openly discuss the mercury issue with patients.

One dentist involved in the suit says ADA claims that the mercury in silver fillings doesn't cause health problems is "bogus."

Bill DeLong, DDS, a dentist in Ellicott City, Md., tells WebMD he has been brought before his state dental board twice for talking to patients about the safety precautions he uses in his office -- including a mercury vapor detector -- when removing fillings.

"I had complaints ... about the fact that I discuss that with patients, and in both instances they tried to either confiscate my instruments or get me to not discuss anything with my patients unless they bring it up first," says DeLong, who uses no mercury when filling patient's teeth.

Chemist Haley insists the ADA is selling "a big lie" to the American public and the nation's dentists by continuing to claim the vapor released by silver fillings is too small to be harmful.

He says studies show that people with silver fillings have an average of four times the amount of mercury in their blood and/or urine than people who have no fillings or nonsilver fillings.

"The ADA says the amount of mercury coming out of fillings is insignificant," says Haley. "But they have yet to publish one paper showing the exact scientific amount that is released. We're scientists -- we don't measure 'insignificant' or 'a little bit' when we do scientific studies. Where are their studies?"

The ADA contends it is a matter of public record that the mercury in the filling material does not cause health problems and says that opinion is shared by all major U.S. public health agencies.

May 29, 2001 -- Chances are, you have had a tooth cavity that needed to be filled. It's a pretty common occurrence. But how often have you have stopped to wonder what those fillings contain -- and what you carry around in your mouth for decades?

According to the American Dental Association, or ADA, up to 76% of dentists use silver fillings containing mercury when filling a tooth. Although the substance used for silver fillings, known as amalgam, has been in use for more than 100 years, the fillings are controversial because of claims that exposure to the vapor from the mercury can cause a variety of health problems ranging from joint pain to multiple sclerosis.

The ADA maintains the fillings are safe and says studies have failed to find any link between silver fillings containing mercury and any medical disorder.

And the ADA is not alone in its position. The CDC, the World Health Organization, the FDA, and others support the use of silver fillings as safe, durable, and cost-effective. The U.S. Public Health Service has said there is no health reason not to use silver fillings, unless a patient has an allergy to a component in the amalgam. The ADA says fewer than 100 incidents of such allergy have ever been reported.

But Bill DeLong, DDS, a dentist in Ellicott City, Md., says the ADA's claim that the mercury in silver fillings doesn't cause health problems is "bogus."

DeLong, who does not use silver fillings, has been brought before his state dental board twice for talking to patients about the safety precautions he uses in his office -- including a mercury vapor detector -- when removing fillings for people who want or need them replaced.

"I had complaints ... about the fact that I discuss that with patients -- and in both instances they tried to either confiscate my instruments or get me to not discuss anything with my patients unless they bring it up first," says DeLong, one of five dentists who are suing in federal court for the right to discuss the potential harm of mercury in fillings or even post information in their offices informing patients of some of the studies that have linked the fillings to health problems.

"When people are seeking advice I think it's only right that they get to hear that there are other opinions," says DeLong, who had his own silver fillings removed 24 years ago.

DeLong uses the mercury detector to show patients how much mercury vapor is released from their fillings. Chewing and eating or drinking hot foods and beverages increase the amount of vapor that is released, although small amounts of vapor are released all the time.

The ADA insists once the filling is placed in the tooth, a person's exposure to mercury vapors is minimal.

"There have been a number of studies looking at the potential effects of mercury from amalgam in the general population, and the preponderance of evidence is that there is no relationship between the presence of amalgam fillings and any disease condition," says ADA spokesman J. Rodway Mackert, PhD.

"Therefore there's no reason for a patient to avoid placement of amalgam fillings, and there's no reason to have amalgam fillings removed for the purpose of trying to alleviate any disease condition," says Mackert, who is a professor at the Medical College of Georgia in Augusta.

But DeLong says by the standards of the Environmental Protection Agency, the amount of mercury in one filling is enough to contaminate a 10-acre pond, making the fish that live in the pond over the mercury limit for human consumption.

"It's hazardous waste," DeLong says of a filling that has been removed. "You have to dispose of it properly, you have to send it to an EPA-licensed facility that handles mercury waste -- this is the very material that just came out of a person's mouth."

There are numerous options to silver fillings, including tooth-colored resin, porcelain, and gold fillings -- all of which are considerably more expensive. Some dentists say colleagues who encourage patients to have silver fillings removed and replaced with the more expensive fillings are just making money off the controversy.

Charles G. Brown, the Washington attorney who represents DeLong, four other dentists, and seven patients in the lawsuit, says American dentists are dropping the ball on an important health issue.

"They know it is going to harm some people. They know, but they discourage warnings," says Brown. "They're keeping people in the dark ... they're incredibly biased on this issue."

The ADA, which is not named in the lawsuit, denies they ever discourage dentists from talking to patients about the issue.

"What we discourage is dentists misrepresenting to patients the value of any therapeutic treatment," says Kathleen Todd, ADA associate general counsel.

A New York City dentist who uses silver fillings agrees with the ADA that the amount of mercury in the fillings is not harmful and that the controversy over their safety is unwarranted.

"With the fillings of today, it's not a problem at all," says Nikolaos Laoutaris, DDS.

He says many people prefer the tooth-colored fillings to the silver fillings for cosmetic reasons anyway, so it may be becoming less of an issue.

But Laoutaris, director of the General Dentistry Program at New York Weill Cornell Medical Center, says he advises patients with fillings that are more than 25 years old to have them removed because the amount of mercury released increases with the age of the filling. Still, he says he doesn't discourage replacing them with silver fillings because the evidence does not support any harm associated with them.