Mercury release from amalgam: a study in vitro and in vivo.

Total mercury release from a high-copper and a low-copper amalgam was measured in a study in vitro using atomic absorption spectrophotometry. Conditions of mechanical agitation and sealant coverage were evaluated over time. Mercury release was found under agitation and no-agitation conditions to increase shortly after preparation and then to level off after 24 to 48 hours. No difference in mercury release was observed for either amalgam type. Sealant coverage of amalgam significantly reduced mercury release under agitation conditions. In an experiment in vivo mercury vapor was measured at different times for patients receiving their first amalgam restoration. Sealant coverage was found to significantly reduce mercury vapor after chewing on this restoration compared to a nonsealant-covered amalgam.