title: [Analysis of the unsuccessful cases of the porcelain-fused-to-metal-crowns and bridges].
abstract: OBJECTIVE
  To discuss the unsuccessful reasons and the preventive methods of the unsuccessful clinic cases.
  
  
  METHODS
  The retrospective analysis was carried on the 80 prosthesis in 70 patients from 1994 to 2001 which were suffered with unsuccessful results after the restoration of the metal crowns and bridges.
  
  
  RESULTS
  There were 68 teeth which had collapsed or broken. 20 teeth had the post loosing or shedding. Root breaking, food impaction, unharmony colors of porcelain and the changing color of gingival were 3, 3, 6 and 2 teeth.
  
  
  CONCLUSIONS
  It is necessary to select suitable repairing materials and operate correctly for preventing the occurring of the unsuccessful results in the porcelain-fused-to-metal-crowns and bridges.
authors.affiliation: Dept. of Prosthodontics, Tianjin Oral Hospital, Tianjin 30041, China.
authors.forename: Li-Yun
authors.initials: LY
authors.lastname: Zhai
authors.forename: Yu-Zhen
authors.initials: YZ
authors.lastname: Zhao
authors.forename: Shao-Ping
authors.initials: SP
authors.lastname: Wang
authors.forename: Yue-Hua
authors.initials: YH
authors.lastname: Yang
mesh_terms: D003442:Crowns; D003776:Dental Porcelain; D006801:Humans; D008670:Metals; D008963:Molar; D012189:Retrospective Studies; D014092:Tooth Root
chemical_list: D008670:Metals; D003776:Dental Porcelain