A long-running controversy

The debate over silver amalgam dates at least to 1845, when the now-defunct American Academy of Dental Surgeons asked its members to sign a pledge never to use it. Though amalgam use has been declining since the 1970s because more eye-pleasing options are available and cavities are smaller, federal lawmakers have introduced a bipartisan bill to ban silver/mercury fillings for children and pregnant and nursing women and to phase them out completely in three years. In California, dentists are required by state law to post a warning that dental amalgams "cause exposure to mercury, a chemical known to the state of California to cause birth defects or other reproductive harm." "The ADA is wrong that the issue is `safety.' The issue is `risk,'" said Charlie Brown, national counsel for Consumers for Dental Choice and Coalition for Mercury-Free Dentistry.

He has filed a petition asking the Federal Trade Commission to investigate the ADA and the Connecticut State Dental Association for what the groups claims is making false, deceptive and unsubstantiated claims in promoting silver/mercury amalgam. "On this point scientists agree: Mercury is a virulent neurotoxin that can permanently harm the developing brain of a child or fetus.

Yet a recent Zogby poll shows three in five people don't know that `silver' fillings have mercury," said Brown, who pointed out that silver fillings are in fact mainly mercury. The ADA staunchly defends the safety of amalgam, still used in about 30 percent of restorations. Amalgam, made by mixing elemental liquid mercury with an alloy powder composed of silver, tin, copper and sometimes smaller amounts of other metals, hardens quickly and tolerates saliva. This makes it useful for treating squirmy young children or special-needs patients who have a hard time sitting still.

By Julie Deardorff