Both studies--one conducted in Europe, the other in the United States--independently reached the conclusion that children whose cavities were filled with dental amalgam had no adverse health effects. The findings included no detectable loss of intelligence, memory, coordination, concentration, nerve conduction, or kidney function during the 5-7 years the children were followed. The researchers looked for measurable signs of damage to the brain and kidneys, because previous studies with adults indicated that these organs might be especially sensitive to mercury.
The authors noted that children in both studies who received amalgam, informally known as "silver fillings", had slightly elevated levels of mercury in their urine. But after several years of analysis, they determined that the mercury levels remained low and did not correlate with any symptoms of mercury poisoning.
The two studies are: the New England study, which was undertaken in the urban Boston (MA) area and rural Farmington (Maine), and the Portuguese study, conducted in Lisbon, Portugal. Each study enrolled over 500 children who had existing untreated decay in permanent posterior, or back, teeth, but no previously placed dental amalgam fillings. Each child was randomly assigned to receive either amalgam or composite resin (tooth-colored) fillings while participating in the research studies. All were evaluated for several years thereafter to determine if any health changes occurred, with emphases on IQ changes in the New England study and on memory, concentration, coordi
Contact: Linda Hemphill
International & American Association for Dental Research