The number of mercury fillings in dental patients should be severely limited to avoid life-long exposure to the toxic metal, says a new Health Canada study.

Mercury vapor released daily from the fillings and absorbed by the body is "the most significant source of mercury, compared to food, indoor and outdoor air, drinking water and soil," says Mark Richardson, a scientist on contract to the federal medical devices bureau which regulates dental material.

Richardson's study, released Monday, proposes restricting the number of mercury fillings to: one in toddlers; one in school-aged children; three in teenagers; and four in adults and seniors respectively.

Those limits, especially for adults and seniors, are less than half the average number of fillings now in the mouths of most North Americans. The silver-colored amalgam fillings typically contain about 50-per-cent mercury mixed with silver and other metals.

Health Canada hired Richardson about a year ago to review the scientific literature and determine the exposure to, and risk of, mercury vapor released by dental fillings.

FINDINGS QUESTIONED

The Canadian Dental Association responded by calling the study's conclusions regrettable.

"It is unfortunate that this literature review may create public anxiety when no new research is involved, and when the conclusions of this review are questionable," said association president Jim Brookfield.

More research is necessary "before any policy is formatted by Health Canada for changing the present use of approved dental materials," added Rick Beauchamp, president of the Alberta Dental Association.

Until the study has been evaluated by the international community and health regulators, "there is no need for patients to have amalgam fillings replaced," Beauchamp said.

Richardson's study -- which nowhere recommends people replace their fillings -- underwent extensive peer review by a blue-ribbon panel of 16 international experts in academia, health, dental sciences and environmental-dental material regulation.

One reviewer, U of C medical physiology professor Dr. Fritz Lorscheider, said the study is "well conceived and thorough." But Richardson noted recent reviews in the U.S. and Sweden "have concluded that there is no evidence to suggest that dental amalgam, specifically, is injurious to health." He added there is still insufficient information on which to base this conclusion.

STUDY WILL INFLUENCE FEDS

Although the study is not binding on Health Canada, it will be a significant factor in setting the new policy expected by next spring, department spokeswomen Monette Hache said from Ottawa.

The study found dental amalgam contributes 50 per cent of the total daily mercury exposure for adults, and between 32 to 42 per cent for toddlers, children and teens -- more than any other source.

HEALTH DAMAGE

To ensure no health damage occurs from chronic exposure to dental mercury, total daily exposure should be no more than 0.014 micrograms of mercury vapor per kilogram of body weight, Richardson recommends.

But an adult with an average number of fillings, for example, already receives a daily dose of at least 3.4 micrograms of mercury from his or her fillings alone.

So the only way to achieve Richardson's proposed limit for adults and other age groups -- at least in patients who don't already have a mouthful of mercury fillings -- is to restrict how many fillings they get.

Calgary Herald Study urges limits on mercury fillings MARK LOWEY, Southam Newspapers

The number of mercury fillings in dental patients should be severely limited to avoid life-long exposure to the toxic metal, says a new Health Canada study.

Mercury vapor released daily from the fillings and absorbed by the body is "the most significant source of mercury, compared to food, indoor and outdoor air, drinking water and soil," says Mark Richardson, a scientist on contract to the federal medical devices bureau which regulates dental material.

Richardson's study, released Monday, proposes restricting the number of mercury fillings to: one in toddlers; one in school-aged children; three in teenagers; and four in adults and seniors respectively.

Those limits, especially for adults and seniors, are less than half the average number of fillings now in the mouths of most North Americans. The silver-colored amalgam fillings typically contain about 50-per-cent mercury mixed with silver and other metals.

Health Canada hired Richardson about a year ago to review the scientific literature and determine the exposure to, and risk of, mercury vapor released by dental fillings.

FINDINGS QUESTIONED

The Canadian Dental Association responded by calling the study's conclusions regrettable.

"It is unfortunate that this literature review may create public anxiety when no new research is involved, and when the conclusions of this review are questionable," said association president Jim Brookfield.

More research is necessary "before any policy is formatted by Health Canada for changing the present use of approved dental materials," added Rick Beauchamp, president of the Alberta Dental Association.

Until the study has been evaluated by the international community and health regulators, "there is no need for patients to have amalgam fillings replaced," Beauchamp said.

Richardson's study -- which nowhere recommends people replace their fillings -- underwent extensive peer review by a blue-ribbon panel of 16 international experts in academia, health, dental sciences and environmental-dental material regulation.

One reviewer, U of C medical physiology professor Dr. Fritz Lorscheider, said the study is "well conceived and thorough." But Richardson noted recent reviews in the U.S. and Sweden "have concluded that there is no evidence to suggest that dental amalgam, specifically, is injurious to health." He added there is still insufficient information on which to base this conclusion.

STUDY WILL INFLUENCE FEDS

Although the study is not binding on Health Canada, it will be a significant factor in setting the new policy expected by next spring, department spokeswomen Monette Hache said from Ottawa.

The study found dental amalgam contributes 50 per cent of the total daily mercury exposure for adults, and between 32 to 42 per cent for toddlers, children and teens -- more than any other source.

HEALTH DAMAGE

To ensure no health damage occurs from chronic exposure to dental mercury, total daily exposure should be no more than 0.014 micrograms of mercury vapor per kilogram of body weight, Richardson recommends.

But an adult with an average number of fillings, for example, already receives a daily dose of at least 3.4 micrograms of mercury from his or her fillings alone.

So the only way to achieve Richardson's proposed limit for adults and other age groups -- at least in patients who don't already have a mouthful of mercury fillings -- is to restrict how many fillings they get.

Calgary Herald Study urges limits on mercury fillings MARK LOWEY, Southam Newspapers

The number of mercury fillings in dental patients should be severely limited to avoid life-long exposure to the toxic metal, says a new Health Canada study.

Mercury vapor released daily from the fillings and absorbed by the body is "the most significant source of mercury, compared to food, indoor and outdoor air, drinking water and soil," says Mark Richardson, a scientist on contract to the federal medical devices bureau which regulates dental material.

Richardson's study, released Monday, proposes restricting the number of mercury fillings to: one in toddlers; one in school-aged children; three in teenagers; and four in adults and seniors respectively.

Those limits, especially for adults and seniors, are less than half the average number of fillings now in the mouths of most North Americans. The silver-colored amalgam fillings typically contain about 50-per-cent mercury mixed with silver and other metals.

Health Canada hired Richardson about a year ago to review the scientific literature and determine the exposure to, and risk of, mercury vapor released by dental fillings.

FINDINGS QUESTIONED

The Canadian Dental Association responded by calling the study's conclusions regrettable.

"It is unfortunate that this literature review may create public anxiety when no new research is involved, and when the conclusions of this review are questionable," said association president Jim Brookfield.

More research is necessary "before any policy is formatted by Health Canada for changing the present use of approved dental materials," added Rick Beauchamp, president of the Alberta Dental Association.

Until the study has been evaluated by the international community and health regulators, "there is no need for patients to have amalgam fillings replaced," Beauchamp said.

Richardson's study -- which nowhere recommends people replace their fillings -- underwent extensive peer review by a blue-ribbon panel of 16 international experts in academia, health, dental sciences and environmental-dental material regulation.

One reviewer, U of C medical physiology professor Dr. Fritz Lorscheider, said the study is "well conceived and thorough." But Richardson noted recent reviews in the U.S. and Sweden "have concluded that there is no evidence to suggest that dental amalgam, specifically, is injurious to health." He added there is still insufficient information on which to base this conclusion.

STUDY WILL INFLUENCE FEDS

Although the study is not binding on Health Canada, it will be a significant factor in setting the new policy expected by next spring, department spokeswomen Monette Hache said from Ottawa.

The study found dental amalgam contributes 50 per cent of the total daily mercury exposure for adults, and between 32 to 42 per cent for toddlers, children and teens -- more than any other source.

HEALTH DAMAGE

To ensure no health damage occurs from chronic exposure to dental mercury, total daily exposure should be no more than 0.014 micrograms of mercury vapor per kilogram of body weight, Richardson recommends.

But an adult with an average number of fillings, for example, already receives a daily dose of at least 3.4 micrograms of mercury from his or her fillings alone.

So the only way to achieve Richardson's proposed limit for adults and other age groups -- at least in patients who don't already have a mouthful of mercury fillings -- is to restrict how many fillings they get.

MARK LOWEY, Southam Newspapers

Calgary Herald November 28, 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