[Comparative studies between various amalgams].

Abstract

A number of dental amalgam products have been compared in the context of a thesis. Four products, each of them possessing different characteristics, have been selected. Six Eighty Amalgam Alloy is a conventional product; Fluor Alloy contains a quantity of SnF2; Amalcap non gamma2 belongs to the group of the so-called non gamma2-alloys; Indiloy is spherical and contains indium. Each product was subjected to a series of tests and investigations: structure, dimensional changes after condensation, compressive strength, behaviour during a relaxation-test and resistance to corrosion. Indiloy was the product with the most interesting structure and it could be ascertained the mercury especially attacked silver and indium of the original alloy. Thus a sort of matrix is formed. The measuring of the dimensional changes was done by introducing a new method. Fluor Alloy and Indiloy present a behaviour that differs a lot from the expected one: at first a contraction followed by a more important expansion. A relaxation-test is an alternative to the creep-test and the connection between both is demonstrated. Combining the results of the resistances to the compressive forces with those of the relaxation-tests shows Indiloy possesses superior mechanical properties while those of Six Eighty Amalgam Alloy are rather inferior. A final series of tests concerns the resistance to corrosion. Amalcap non gamma2 and Indiloy have a much greater rough resistance to corrosion than the two other ones.