Characterisation of Ag-Sn-Cu Dental Amalgam Powder and Its Amalgam Triturated with Nominal and Higher Pressure

摘要

Ag-Sn-Cu lathe cut particles of dental amalgam powders are mixed with mercury with an approximate 1:1 ratio. Mercury and amalgam powder mixtures are triturated at nominal pressure and at higher pressure applied intermittently, and then condensed into an acrylic mould with reasonably higher condensation pressure as well, followed by setting at room temperature for different time period. The microstructural features of the amalgam alloy powders and its amalgams of various states are studied by FESEM, X-ray elemental mapping, X-ray diffraction, differential scanning calorimetry and by hardness measurement as well. Results showed that the amalgams triturated with higher pressure have yielded finer matrix gamma(1) (Ag2Hg3), presence of Ag-rich beta(1) and finer unreacted gamma (Ag3Sn) phases with reduced porosity and higher hardness.