The most recent in vitro evidence provides new insight into the effects of mercury on
developing neural brain cells at concentrations similar to those accumulated in human brain and found in post mortem specimen. The effects of genetic polymorphism concerning mercury kinetics may influence the degree of individual susceptibility with regard to mercury internal exposure and consequently toxicity. This may raise some concern for possible effects on the brain of mercury originating from dental amalgam. However, so far such effects have not been documented in humans, although some evidence on alteration of mercury dynamics have been reported.
Placement and removal of dental amalgam fillings results in transient short-time exposure to the patients compared to leaving the amalgam intact. There is no general justification for unnecessarily removing clinically satisfactory amalgam restorations, except in those patients diagnosed as having allergic reactions to one of the amalgam constituents. However, as with any other medical or pharmaceutical intervention, caution should be exercised when considering the placement of any dental restorative material in pregnant women.