Introduction

Amalgam fillings do not adversely affect the development of children's brains, according to research published in the February 2008 issue of the Journal of the American Dental Association.

The report comes from a joint team of researchers from the University of Lisbon, Portugal and the University of Washington, Seattle, USA and looked at the possible neurological effects of amalgam restorations. The team studied 507 Portuguese children aged 8-12 over a seven-year period beginning in 1997. The children received either amalgam or composite resin restorations.

Two types of neurological signs, 'hard' and 'soft', were assessed in the children using routine clinical neurological examinations. Hard signs indicate damage to specific neural structures, while soft signs are very subtle signs of central nervous system dysfunction that are likely to point to immature sensory motor skills rather than any specific damage to the brain. The children were also evaluated for the presence of tremor.

After seven years, there was no difference between the group with amalgam restorations and the group with composite fillings in terms of the presence or absence of hard neurological signs or tremor. Additionally, no differences in the presence, absence or severity of soft signs were found between the two groups and any soft signs found diminished as the children aged, as would be expected in healthy children.

The authors conclude that even at average amalgam exposure levels of 7.7-10.7 amalgam surfaces per subject over seven years, mercury exposure from dental amalgam does not adversely affect neurological status.