Investigation of CoCr Dental Alloy: Example from a Casting Workflow Standpoint

Cobalt-chromium (CoCr) alloys have been used in dentistry for dental bridges, crowns and implants decades. When using CoCr alloys, a number of fractures occurred the Dental Laboratory, both when handling castings after they placed patient’s mouth. It is assumed that key cause resulting bridges casting process, which includes preparation mixing basic components alloy, unstable solidification final treatment tooth surface. The aim this study was, therefore, to examine three differently prepared from alloy. For initial we selected one supplied directly manufacturer; test samples were alloy remelted four times same crucible, while fourth sample was remaining solidified taken at last remelting. Characterisation microstructure all performed by optical scanning electron microscopy equipped with an energy dispersive X-ray spectroscope diffractometry. Microhardness measurements also performed. investigation revealed composed matrix eutectic interdendritic composition precipitates, rich W Mo. two oxides identified as chromium oxide silicon content oxide, originated residue. high can be attributed ceramic melting mixed remains melting. second showed more regular elemental small quantity impurities Based on research, some recommendations made working reducing risk bridge future.