Many people rush to have their amalgam fillings replaced out of fear that the cavity-fillers are making them sick, but a team of German scientists says such fears may be all in their heads.
Amalgam fillings, in use since 1830, are strong and durable, but contain about 50% mercury, a toxic metal that can lead to impaired learning and memory.
Psychologists at the University of Heidelberg at Mannheim looked at 40 patients complaining of health problems such as headaches, anxiety and inability to concentrate that the patients blamed on their fillings.
In a study appearing in a recent issue of the magazine New Scientist, the researchers compared those folks with 40 others who had a similar amount of metal in their mouths, but didn't describe the same problems. They found comparably low levels of mercury in the saliva, blood and urine of both groups.
However, the researchers found that a large proportion of those complaining of illness had histories of psychological problems, such as symptoms of depression and obsessive attitudes toward their health, compared with just a few of those in the control group.
Anton Rudolf, one of the lead researchers, believes they were not imagining their symptoms, but would have looked elsewhere for the source of their symptoms had they not heard bad news about amalgam.