title: [Effect of porcelain firing cycle on microstructure and corrosion resistance of 4 metal ceramic alloys].
abstract: OBJECTIVE
  To determine the effect of porcelain firing cycle on microstructure of 4 metal ceramic alloys, and to analyze the changes of their corrosion resistance in the artificial saliva.
  
  
  METHODS
  We simulated the process of firing and repolishing when fabricating porcelain-fused-to-metal restoration in clinic,and then observed the microstructures of Ni-Cr, Ni-Cr-Ti, Co-Cr alloys and high gold alloy by field emission scanning electron microscopy and energy dispersive spectroscopy. The electrochemical corrosion behavior of alloys in artificial saliva was analyzed by polarization curves and corrview 2 corrosion analysis software. The data of self-corrosion potential and transpassive potential were obtained and analyzed.
  
  
  RESULTS
  After the porcelain firing cycle, the surface composition changed slightly, and the morphological in the 3 predominate base metal alloys also changed. The self-corrosion potential turned to more negative, and the transpassive potential declined.
  
  
  CONCLUSIONS
  The procedure of porcelain firing cycle can affect the surface microstructure and increase the corrosion of 4 metal-ceramic alloys.
authors.affiliation: Department of Stomatology, Xiangya Hospital, Central South University, Changsha, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Hui
authors.initials: H
authors.lastname: Cai
authors.forename: Guo-fu
authors.initials: GF
authors.lastname: Xu
authors.forename: Chang-yun
authors.initials: CY
authors.lastname: Fang
mesh_terms: D003343:Corrosion; D003735:Dental Casting Technique; D003776:Dental Porcelain / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D012464:Saliva, Artificial; D013499:Surface Properties
chemical_list: D016876:Metal Ceramic Alloys; D012464:Saliva, Artificial; D003776:Dental Porcelain