title: Microscopic examination of embrittled pin-retained base metal casting.
abstract: Differential thermal analysis, optical microscopy, scanning electron microscopy, and energy dispersive radiographic analysis were used to examine and analyze two failed platinum-palladium-gold pin-retained nickel-chromium castings. The microstructure and chemical composition of the pin-casting interface were different from those of the pin and the cast alloy. Porosity was also observed at the interface. The observations with these samples suggest that the pin melted during casting. The embrittlement and failure of plantium-palladium-gold pins cast with nickel-chromium alloy have been attributed to this melting phenomenon. Further study is necessary to determine whether these observations are valid for a large number of samples.
authors.affiliation: Department of Biomaterials, Louisiana State University, School of Dentistry, New Orleans.
authors.forename: R S
authors.initials: RS
authors.lastname: Walker
authors.forename: N K
authors.initials: NK
authors.lastname: Sarkar
authors.forename: R J
authors.initials: RJ
authors.lastname: Ciolino
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002858:Chromium Alloys; D003442:Crowns; D004055:Differential Thermal Analysis; D004577:Electron Probe Microanalysis; D004868:Equipment Failure; D006047:Gold Alloys / Q000032:analysis; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D010165:Palladium / Q000032:analysis; D010984:Platinum / Q000032:analysis; D011176:Post and Core Technique
chemical_list: D002858:Chromium Alloys; D006047:Gold Alloys; D010984:Platinum; D010165:Palladium