Two new studies have concluded that amalgam fillings do not lead to neurological or renal disorders in children. The papers, both published in the Journal of the American Medical Association, provide more evidence that amalgam restorations are safe to use and pose no risk to human health.

In the first study (Bellinger D C, Trachtenberg F, Barregard L et al. J Am Med Assoc 2006; 295: 1775–1783), researchers monitored a group of 534 six- to 10-year-olds in New England for five years after they had been randomly assigned either amalgam fillings or fillings containing no mercury. They looked at the children's IQ, memory, cognitive function and kidneys to see if they were affected by the fillings. The second study looked at a group of 507 children with amalgam fillings in Lisbon, Portugal (DeRouen T A, Martin M D, Leroux B G et al. J Am Med Assoc 2006; 295: 1784–1792) and monitored them for seven years to see whether the fillings had any neurological effects.

Although children with amalgam fillings were found to have slightly higher levels of mercury in their urine than control groups, both studies found no significant differences between children with amalgam fillings and those with resin composite fillings containing no mercury. The authors of the first study conclude that 'Under the conditions of use represented in this trial, there is no reason to discontinue use of mercury amalgam as the standard of care for caries in posterior teeth.'

It is hoped that these new results will help to reassure those concerned about the safety of amalgam as a dental restorative. Despite previous studies showing similar results to the recent findings, fears that amalgam fillings are not completely safe have persisted since the 1980s, when scientists showed that amalgam fillings released mercury vapour into the mouth that was then inhaled and absorbed by the body.