– Two types of gold alloys and one type of pure titanium have been submitted to corrosion in artificial saliva for periods of up to about 2 months. The release of copper, gold or silver from the golod alloys as well as titanium from the titanium matrix was measured with nuclear tracer technique. The physical/chemical state of the corrosion products of gold alloys referring to the ionic state or presence in particulate form has been examined retaining the particulate matter on a glass filter. Copper wad observed to be mainly present in the ionic state. Considerable amounts of gold were observed to be retained on the glass filter explained by the presence of gold in particulate form or as a component of a dispresed colloidal phase. The estimation of the relase of titanium was registered by the tracer nuclide 46Sc assumining particulate matter to be deteriorated from the titanium surface.

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– The amounts of copper, mercury, silver or zinc released from two brands of freshly prepared, lathe cut amalgams and from one brand of dispersed phase type amalgam into artificial saliva have been measured. Samples were immersed in the solution a few minutes after the end of trituration and exposed statically for periods of up to about 4 days. The initial mercury release from such specimens could exceed the long term mercury release from old amalgams by more than two orders of magnitude. The measurements indicate that during the first day after insertion of two amalgam fillings, each with an assumed surface area of 1 cm2 and under presumably static conditions, mercury at the level of more than twice the mercury food and drink intake could be released in the oral cavity. This is, however, a situation which appears infrequently, e.g. following dental treatment once a year. The amounts of copper and zinc released initially were considerably lower than the corresponding food and drink intake values, while silver might be on the same level. The measurements were conducted using nuclear tracer techniques.

– Corrosion during static creep of two γ2‐containing and one dispersed phase amalgam immersed in artificial saliva has been observed, using SEM, to occur in γ1‐grain boundary regions where grain boundary sliding and dislocation slip take place. Cracking in the interior of γ1‐grains has also been found, in particular for dispersed non‐γ2 amalgam. The combined action of corrosion and stress favored the formation of cracks. Signs of similar creep processes which may promote cracks have also been noted after cyclic loading where the accumulative strains were much lower than in the static creep experiments. Due to these low strains and short immersion times corrosion attacks of the same kind as under static loading can only be assumed. Using nuclear tracer technique quantitative measurements of the corroded material from samples exposed to cyclic loading showed the dispersed non‐γ2 amalgam to release more Hg, Cu and Zn than the two γ2‐containing amalgams and that 50–90% copper and mercury were present as particulate matter. These observations can be explained on the basis of different tendencies to Cracking in the amalgams. Cyclic loading increases the rate of degradation by one or two orders of magnitude compared with corrosion without loading. Reported studies of marginal degradation in non‐γ2 amalgams compared with γ2‐containing amalgams do not agree with the present in vitro experiments.