In April, Renee Brodie had the last of the 13 silver fillings in her teeth taken out and replaced with porcelain.

The Delta, B.C., woman had been suffering from chest pains, headaches, fatigue, anxiety, memory loss and a host of other life-destroying symptoms.

Finding out what was wrong took several years of detective work, but after consulting five doctors and four naturopaths, she came to the conclusion that the mercury in her silver fillings was making her sick.

Brodie said the $2,000 it cost to replace her fillings was money well spent. She feels much better now and looks relaxed and youthful at 75.

"I just have five symptoms left, and I'm working on those," said Brodie, who has written an article on her experiences and beliefs, titled Poison in Your Mouth.

"One is short-term memory loss because [mercury] affects the brain, so I'm taking Gingko biloba [a plant-derived product available at health food stores] for that.

"I've still got the dry mouth and throat, and frequent urination, because it affects the stomach and the kidneys."

Brodie is one of many people who have come to mistrust dental amalgam, a silvery mixture of metals that has filled billions of cavities over the last 150 years.

Amalgam is made of silver, mercury, tin, copper and zinc.

Although as many as 200 million North Americans are walking around with amalgam fillings in their mouths, Brodie hopes future generations will avoid "mercury poisoning" by choosing any one of about 20 alternative materials for their fillings.

Her beliefs are fuelled by the research being done by people like Dr. Murray Vimy, a dentist who is on the medical faculty at the University of Calgary.

Vimy and his colleagues have put amalgam fillings in mice and sheep and tracked the mercury vapor that is released into their bodies as they chew.

In a telephone interview, Vimy said animal studies have linked low-level mercury exposure to four pathologies: kidney dysfunction, antibiotic resistance, Alzheimer's disease and immune-system deficiencies.

His work over the past 15 years has led him to say publicly that "there is no safe threshold for mercury exposure, none."

In 1990, Vimy was featured on the television show 60 Minutes in a frightening segment called Is There Poison in Your Mouth?

Consumer Reports and the Washington Journalism Review later denounced the segment as biased and unbalanced.

Vimy calls himself "a traditional dentist. "Probably the one thing I do that's different from most dentists is I don't use amalgam," he said.

"I'm not recommending that we take the fillings out to cure anything. I'm recommending we stop using it."

He said that if dental amalgam were put through today's regulatory processes, it would never be approved for use.

Dorin Ruse, a University of B.C. scientist, agrees with Vimy on that point. But Ruse disagrees with Vimy and others who call amalgam dangerous, saying the science just doesn't support that view.

Ruse said people's exposure to mercury from fillings is so minimal it can be considered negligible.

He cited a U.S. study, published in May, which simulated chewing in an "artificial mouth" and measured the amount of mercury released.

"It came out to 0.03 micrograms per day from a single amalgam filling. That is really low."

A microgram is one-millionth of a gram. Ruse said people who live in coastal areas and have a diet rich in fish are exposed to 100 to 300 micrograms of mercury a day.

Dr. Roy Thordarson, registrar of the College of Dental Surgeons of B.C., said: "Amalgam has been one of the major forces in the prevention of dental disease. If we hadn't had amalgam over the years, only the rich could have kept their teeth. [Until recently], all we had was gold or amalgam."

Thordarson said hundreds of millions of amalgam fillings are being placed in the mouths of people around the world and, "to be crass and blunt, they aren't dropping dead."

He said he sees the use of amalgam waning as better dental hygiene reduces the number of cavities people get and he insisted dentists will stop using amalgam if it is found unsafe. "If anything is ever proven, we will be the first ones to throw it in a pit and bury it."

Canada will soon develop its own position on the safety of dental amalgam, rather than taking its cue from other countries.

Philip Neufeld, chief of research and surveillance in Health Canada's bureau of medical devices, said public concern over amalgam cannot be ignored.

Alluding to statements by Health Minister Diane Marleau, he said: "If the information indicated there were risks to public health, we would take whatever steps were necessary to minimize those risks."

Rebbeca Wigod, Southam Newspapers

Vancouver Sun August 18, 1995

Also make sure to read these books: Poison in Your Teeth: Mercury Amalgam (Silver) Fillings...Hazardous to Your Health! and Mercury Detoxification by Tom McGuire