Health Canada says there's no need to get amalgam yanked

Health Canada is advising people not to rush out to their dentists to have their mercury fillings yanked just yet, despite a federal health study proposing limits on their use.

Meanwhile, city dentists on both sides of the debate predict dental insurance costs will climb if Health Canada decides to follow the study's recommendation to put a cap on the number of mercury fillings people should get.

"For the general population, there is no need to remove your fillings as a precaution" against potential long-term health damage, said Philip Neufeld, chief of research and surveillance in Health Canada's medical devices bureau.

Neufeld said if people believe their fillings are making them sick, they should consult a toxicologist, or poison expert, to determine whether they've been exposed to sufficient mercury to harm them.

A new study, done for Health Canada by consultant scientist Mark Richardson, proposes that adults get no more than four amalgam fillings, teenagers three, and toddlers and schoolchildren one.

Those numbers represent "tolerable daily intakes," which would ensure no lifelong health risk for people exposed to mercury vapor released daily by the fillings.

Federal Health Minister Diane Marleau says she's concerned about the report, but will wait for more advice from a Health Canada advisory panel before announcing a position -- expected in the spring.

Neufeld noted that Richardson's tolerable daily intakes represent a "long grey scale" of risk, rather than a black or white assessment.

It does not mean that having a fifth filling if you're an adult, for example, would make you sick, Neufeld said.

Since there's no direct evidence of health damage from dental amalgam, Richardson's estimates are based on observed effects in industrial workers exposed to high levels of mercury vapor, added Neufeld.

Calgary dentist Dr. Bill Wilson, who uses amalgam and has a mouthful of the fillings, predicted dental insurance costs will rise if Health Canada restricts their use.

Alternative materials, such as white "plastic" fillings, "don't last nearly as long," so patients will need their fillings replaced more frequently, Wilson said.

Porcelain or gold inlays are durable, but most dental insurance plans don't cover their total cost unless these alternatives are deemed necessary, he said.

Another local dentist, Dr. Bill Cryderman, said the scientific medical research convinced him to stop using mercury fillings eight years ago.

More than one tonne of the toxic heavy metal is placed in the mouths of North Americans every day, Cryderman said. "We know mercury's a poison. It's considered a toxic material everywhere except in people's mouths."

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.

The cost

Comparative prices (approximate):

For three tooth surfaces:

        Bonded amalgam: $87;
        Bonded resin: $107;
        Porcelain or gold inlay: $425.
    For five tooth surfaces:
        Bonded amalgam: $116;
        Bonded resin: $146;
        Porcelain inlay with gold crown or all-gold crown: $600.

Source: Alberta Dental Association

MARK LOWEY, Southam Newspapers

Calgary Herald November 29, 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