Mercury and copper release from amalgams in different soft drinks

Release of mercury and copper over time from three different non-gamma-2 amalgams in a polished and unpolished state was tested in water and two soft drinks. The measuring methodology was geared to warrant minimum Hg losses due to evaporation and adsorption. Initial (24 h) values for Hg and Cu were relatively high in water, but were much lower in the soft drinks. The 24-104-hour values were much lower than the initial readings for all amalgams and all environments. Polishing reduced leaching--significantly, however, only in water and for only two of the three amalgams. The lower values in the soft drinks and over time could be due to passivation of the amalgam. Passivation appears to be time-dependent and chemically influenced by the environment.