title: Failure modes and fracture origins of porcelain veneers on bilayer dental crowns.
abstract: The aims of this study were to determine the fracture origins and crack paths in the porcelain of clinically failed bilayer ceramic restorations and to reveal the correlation between the porcelain failures and material properties. Three clinically failed crowns of each material (bilayer zirconia crowns, galvano-ceramic crowns, and porcelain-fused-to-metal crowns) were collected and underwent failure analysis. The fractures found in porcelain veneers showed several characteristics including wear, Hertzian cone crack, chipping off, and delamination. The results indicated that the fracture origins and features of the porcelain in bilayer ceramic restorations might be affected by the rigidity of core materials and thickness of copings.
authors.forename: Yihong
authors.initials: Y
authors.lastname: Liu
authors.forename: Guanghua
authors.initials: G
authors.lastname: Liu
authors.forename: Yong
authors.initials: Y
authors.lastname: Wang
authors.forename: James Zhijian
authors.initials: JZ
authors.lastname: Shen
authors.forename: Hailan
authors.initials: H
authors.lastname: Feng
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry; D003442:Crowns; D003764:Dental Materials / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry*; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear; D003801:Dental Veneers; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry
chemical_list: D002858:Chromium Alloys; D003764:Dental Materials; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide