A small amount of mercury is released from dental amalgam restorations and may be absorbed in the human body. Although restorations are believed not to be a health hazard to a large majority of patients, some concern remains because of the toxicity of mercury. The goal of this research is to gain a scientific understanding of the processes involved and to use the knowledge to minimize the release. The study will be performed in the laboratory using a simulated oral environment. The objective is to measure the rate of the processes, which are believed to play major roles in the mercury release: dissolution of mercury from a surface, which has been stripped of the protective film, repassivation of the amalgam surface after film stripping, and changes in the chemical form of mercury after dissolution in the liquids. The rates of these processes will be determined for representative dental amalgams and as a function of major variables, such as pH, temperature, and chemistry of the environment. The experimental techniques will include solution analysis by Atomic Absorption Spectrophotometry, and electrochemical measurements. The results of the study will identify the factors that have major roles in the mercury release, and provide quantitative information on the rates of the reactions involved. They will serve as a basis for a selection of measures to lower the release.
