MANS MERCURY LOADING FROM A DENTAL AMALGAM

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