Smile when you say mercury

Parents may not rest any easier, but two independent studies show dental fillings with mercury do not cause measurable neurological problems.

Worrying about their children is stamped in a parent's DNA. It's what we do and science is sometimes the least of it. But for anxious parents, the new findings are worthy of note.

The studies, including one by University of Washington researchers, are detailed in the recent issue of the Journal of the American Medical Association. The verdict: no discernible neurological damage in kids who received fillings made with mercury.

The studies are significant because they are the first to compare apples with apples: children receiving mercury amalgam fillings with children whose fillings were a composite of other materials.

Despite the studies, many parents will continue to avoid mercury. An estimated 70 percent of all dental fillings done in the U.S. no longer contain mercury. A combination of materials such as plastic and silicate are used instead.

Some dentists still swear by amalgam mercury because of its lasting wear — up to 14 years compared with four to six years for resin. But all evidence points to the filling's growing disuse.

Part of it is aesthetics. Silver in the mouth is so 1980s. The whiteness of resin fillings blends with teeth. But a sizable part is a stubborn resistance to accept mercury's relative safety and effectiveness, points underscored by the two studies.

A similar circumstance is found in the lingering debate over vaccines and autism. Studies have not found a connection between vaccines and higher incidences of autism. Yet, a very real thingfuels the mercury and vaccine debates: fear. Science has not found a way to absolve parents of their fears.