OTTAWA - Dental fillings containing mercury aren't making Canadians sick even though medical evidence about them isn't ironclad, says the Health Department.

After years of study, the department has decided to defend in most cases the continued use of the silver-colored fillings, or dental amalgam, that includes a mixture of metals including mercury.

"A total ban on amalgam is not considered justified," Dr. Philip Neufeld, a director of research with the health protection branch, said Wednesday.

"Neither is the removal of sound amalgam fillings in patients who have no indication of adverse health effects attributable to mercury exposure."

A series of studies, including an internal report by the department, have raised alarms about the dangers of the fillings.

Countries such as Germany, Denmark and Sweden are moving to phase out or ban the use of amalgam.

Neufeld said there have been no conclusive studies proving amalgam is safe, but there is also no evidence it poses a significant risk for most people.

"We still don't believe that mercury is making the general population sick," said Neufeld.

To be safe, the department recommends that dentists consider using other kinds of fillings in the primary teeth of young children.

And they are to avoid using amalgam for patients with kidney problems or sensitivities to mercury.

Women shouldn't have amalgam fillings installed or removed during pregnancy, although there is no evidence that existing fillings pose a significant risk to the fetus, Neufeld said.

Barry Dolman, president of the Canadian Dental Association, welcomed the ruling.

Dolman, a Montreal dentist, said a lot of unwarranted fears have been raised about amalgam fillings.

He said amalgam is still an inexpensive, easy to apply and extremely durable way to fill cavities. That outweighs the minor risks, he said.

"Research has shown that when an individual with a lot of silver fillings is chewing, there is mercury vapor that is released," he said.

"The question is, is it significant?" he asked.

"Based on the science we know now, it will not affect the longevity of the patient's life."

Other materials, such as resins, also contain chemicals, he noted.

Neufeld added that if dentists were greedy, they would recommend removing amalgam fillings.

"You'd never get an appointment, we'd be so busy."

Amalgam is an alloy including silver, tin, copper and mercury.

Amalgam fillings have been used since the mid-1800s, but alternatives such as white resins and ceramic inlays are growing in popularity.

Mercury can cause brain or kidney damage.

An amalgam filling can be as cheap as $30 compared with several hundred dollars for other materials such as ceramics. Resin fillings, although inexpensive, aren't considered as durable as amalgam.

"But even if the costs were the same, I wouldn't recommend banning the material,"said Neufeld.

Clyde Graham, Canadian Press Aug. 21, 1996

Mercury fillings: the facts

• History: Used for about 150 years in North America.
• Composition: Alloy of silver, tin, copper, zinc, mercury and other metals.
• Risks: Single largest source of mercury exposure for Canadians. Traces of toxic mercury vapor are released from fillings by chewing.
• Benefits: Inexpensive, durable and easy to work with.
• Use: Declining over the last 10 years. Less than half of all fillings now are amalgam.
• Alternatives: Composite plastics, ceramics and gold.

Mercury Fillings: The options

• Alternative fillings include white "plastic" composites, porcelain or gold inlays, and all-gold crowns.
• Newer composites are expected to last about seven years, compared with 20 or more for mercury amalgams.
• Most dentists prefer amalgam over composites to fill large cavities in back teeth.
• Porcelain and gold lasts longer than either amalgams or composites, but are much more expensive.
• Most dental insurance plans won't pay for porcelain or gold when amalgams or composites will do the job.

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