Observation of gold alloys ; type III
In prosthetic therapy noble dental alloys are used as a standard part. In order to avoid polymetallism and symptoms of allergy, dentist should be familiar with alloys' composition and main mechanical properties. Laboratory procedures have the greatest influence on the microstructure and properties of cast dental alloys. The aim of this study was to evaluate three commercially available gold alloys, used for the same therapeutic indications. Analyzed were alloys' composition, microstructure and microhardness. Samples were centrifugally cast in a phosphate-bonded investment material. Molds were cooled in the air. The composition was estimated by ICP-OES. The microstructure was analyzed with light microscope and field emission SEM. The results showed both compositional and microstructural differences between declared and obtained values. Microhardness values were similar. It could be concluded that laboratory procedure of casting low-gold alloys has greater influence on their microstructure and properties than their composition does.