Microprobe analysis of dental amalgam alloy particles of Ag-Cu eutectic composition

An electron microprobe was used to investigate the composition and microstructure of commercially available, and experimental dental amalgam alloy particles of approximately Ag-Cu eutectic composition. The method of alloy and amalgam specimen preparation and the technique used in microprobe analysis have been briefly outlined. The dispersant particles in one commercial alloy were of Ag-Cu eutectic composition (28.1% Cu), in another commercial alloy they were Cu-rich (31% Cu). Although the dispersant particles were predominantly of uniform appearance, there was evidence in some particles of an internal structure pattern, small spherical inclusions or voids. The possible composition of the Cu-rich inclusions was investigated using particles from an experimental alloy of approximately Ag-Cu eutectic composition.