Man's mercury loading from a dental amalgam.

The release of mercury from an amalgam surface in natural saliva during cyclic loading, as well as under static conditions, simulating the clinical conditions of chewing and rest, has been studied using a nuclear tracer technique. Cyclic loading strongly promoted degradation of the amalgam surface in the saliva environment. Corrosion products were found to be loosely bound on the amalgam surface and could be removed by brushing similar to toothbrushing. Most of the mercury released from the surface was present in amalgam particles, produced during the cyclic loading procedure. The daily release of ionic mercury was estimated to be approximately 3 micrograms/cm2, according to the model experiment. Extrapolating the present findings to clinical conditions, man's ionic mercury intake from dental restorations may be at the same level as the total mercury intake from food and drink.