The debate over the continued use of mercury in dental fillings was the focus of Thursday's FDA town–hall meeting in Orlando as more than a dozen anti-mercury activists demanded that the government restrict or ban them.

Although mercury is considered toxic, the Food and Drug Administration has classified amalgam fillings — the silver-colored fillings, which contain mercury — as safe. Activists noted that several European counties, including Sweden, Denmark and Norway, have banned use of mercury fillings in recent years.

Although dentists can use other types of fillings — composite materials or gold — experts say that these are more expensive than the mercury alternatives.

At the Orlando hearing, FDA officials — led by Dr. Jeff Shuren, head of the agency's Center for Devices and Radiologic Health — said they have reconvened a scientific panel to study the agency's position on amalgam fillings. Shuren would not say, however, what action the agency might take — or when a decision might be made.

"If I had my druthers, I would like to say something this year," said Shuren, adding that the agency would have to reconsider the scientific and legal issues.

"I empathize with all the people who have experienced medical problems, whatever the cause may be," Shuren said. "We take it seriously, which is why we've reconvened our scientific advisory panel."

Among those at the Orlando town-hall meeting was Freya Koss of Pennsylvania.

"I am one of millions of Americans who have suffered grave medical costs from mercury dental fillings," said Koss, who said she was diagnosed with lupus, multiple sclerosis and myasthenia gravis in 1998, after a dentist removed a mercury-laden amalgam filling and replaced it with a similar one. Within a week, Koss began experiencing double vision, droopy eyelids and a loss of equilibrium. Her symptoms gradually disappeared, she said, after she had her mercury fillings removed.

Also lining up to speak were three dentists, including Dr. James Hardy of Winter Park, who does not put in mercury fillings. Hardy, author of a book titled "Mercury Free," said that any unused dental amalgam is considered hazardous waste and must be disposed of carefully.

"After it [an amalgam filling] is taken out of a patient's mouth, it is treated as hazardous waste," Hardy said. "But somehow, when it is in the patient's mouth, it is not."

Because much of the debate focuses on the extraction of the mercury during removal of old fillings, Hardy takes it a step further. He has invested in a system that prevents particles of mercury from being spread through the air.

This is the second FDA town-hall meeting where anti-mercury activists have dominated the agenda. The first, held in Dallas in March, featured dentists and consumers who complained that mercury caused a myriad of health problems.

Yet the American Dental Association says that dental amalgam "is considered a safe, affordable and durable material that has been used to restore the teeth of more than 100 million Americans."

And at the University of Florida College of Dentistry, Associate Dean Boyd Robinson said scientific evidence hasn't shown harm from mercury fillings.

"Even the people who hate it haven't been able to prove it," Robinson said.

However, the days of mercury fillings, used since the Civil War, may be slowly ending anyway. At UF's dental clinics and dental school, 80 percent of the fillings students now put in are composite fillings — tooth-colored fillings made of crushed silicate glass and resin — while only 20 percent are amalgam. That ratio has flipped from 15 years ago, he said, when 80 percent of the fillings were amalgam.

Although amalgam fillings historically have lasted longer than composite fillings, many patients today prefer the look of the tooth-colored fillings.

"When you say, 'I can put a silver-colored filling in your mouth or a tooth-colored filling,' people pick the tooth-colored filling," Robinson said.

However, composite or resin fillings are more expensive than amalgam fillings, and low-income patients, he said, may be more likely to get amalgams.

lshrieves@tribune.com or 407-420-5433