Study of the thermal, mechanical and costrictional properties to some Foreign dental amalgams using in Iraq

Abstract

In this paper, the preparation of five samples of amalgam alloy used for the restoration of teeth has been done using the  amalgamation device for mixing alloys with mercury. The alloys included four high copper amalgams which are (SDI, Septalloy NG 50, YDA alloy, TG alloy) and the percentage of copper (28, 22.7 , 25, 24) % respectively, which are ready fillings. While the fifth alloy (Septalloy NG70) is for low copper amalgam with Copper ratio of  12.7%. The X-ray diffraction has been tested to study the structural properties of these samples and found for the four high-copper alloys increment in the intensity for the diffraction values of the two phases Ɛ - Cu₃Sn, ƞ - Cu₆Sn₅ with the disappearance of the phase γ₂ - Sn₇Hg which decreases the intensity  of this phase with copper increment, while in the low- copper alloy it shows an increase in the peaks representing the phases Ɛ - Cu₃Sn, ƞ - Cu₆Sn₅ with an increasing proportion of copper in the amalgam, as the relationship is positive between copper increment and the tops increment of these two phases, and the relationship is inverse between the copper ratio increment in amalgams and phase γ₂ where phase reacts with Eutects silver - copper component phases γ₁ - Ag₂Hg₃, ƞ - Cu₆Sn₅. Also the mechanical and thermal properties has been studied for each one of five groups of amalgam alloy like compressive strength , micro hardness , thermal conductivity