‘Mercury poisoning’ from dental amalgam—an evaluation of the evidence

Abstract

The purpose of this paper is to examine the claims that mercury release from dental amalgam restorations may produce toxic reactions in some patients. It first reviews the evidence for the release of mercury from dental amalgam during its insertion into the tooth, removal of amalgam fillings and the functional life of the restorations, and also from amalgam tattoos. It then reviews the absorption and excretion of mercury and discusses the possibility of mercury toxicity. Finally, reports of alleged cases of mercury toxicity from dental amalgam are compared with known clinical symptoms of chronic mercury toxicity and hypersensitivity. This shows that the various symptoms which have been reported do not fit into any one pattern of mercury toxicity. Although it is not possible to completely rule out adverse effects in a minority of susceptible patients, it is concluded that there is insufficient evidence to justify the claims that mercury from dental amalgam restorations has an adverse effect on the health of the vast majority of patients.