Two widely-reported studies in the April 19 JAMA found that mercury-containing "silver" dental fillings pose no detectable threat to children's health or neurologic development. The studies—one led by Children's Hospital Boston neurology researcher David Bellinger, PhD, and one from the University of Washington—were the first randomized clinical trials to directly compare so-called dental amalgam with white composite fillings.
Although the studies drew criticism from groups
opposed to amalgam, Dr. Bellinger and his colleagues find them reassuring. "These are the best designed studies to date, and they showed no substantive differences in the children's development," says Children's pediatric dentist Howard Needleman, DMD.
With over 500 subjects, Dr. Bellinger's study had enough power to detect as little as a three-point decrease in IQ, and found no such decrement. However, he allows that certain subpopulations may be sensitive to amalgam, and cautions that neither study included children under age 6, who could be more vulnerable to mercury's effects.