title: Survival and chipping of zirconia-based and metal-ceramic implant-supported single crowns.
abstract: OBJECTIVE
  The objective of this retrospective study was to compare the incidence of chipping of implant-supported, all-ceramic, and metal-ceramic single crowns.
  
  
  METHODS
  One hundred fifty-three patients (51.7% male, mean age 55.0 years) received 232 cemented implant-supported single crowns. One hundred and seventy-nine crowns had a metal framework (gold alloy) and 53 crowns were all-ceramic (zirconia framework and glass-ceramic veneer material). Age, gender, kind of cementation, and location of the restorations were assessed as possible factors affecting chipping.
  
  
  RESULTS
  During the observation period of up to 5.8 years (mean 2.1 years; standard deviation 1.4), a total of 13 (24.5%) all-ceramic and 17 (9.5%) metal-ceramic crowns suffered from chipping, a difference that was statistically significant. A total of ten single crowns had to be remade resulting in survival of 86.8% (all-ceramic) and 98.3% (metal-ceramic). The other possible factors did not have a significant effect on the chipping.
  
  
  CONCLUSIONS
  Chipping was found to be more frequent for all-ceramic implant-supported single crowns. If the reasons for the vulnerability of all-ceramic crowns remain unknown, implants with all-ceramic single crowns should generally be recommended with care.
authors: Department of Prosthodontics, University of Heidelberg, Heidelberg, Germany. Stefanie.schwarz@med.uniheidelberg.de
authors: Stefanie
authors: S
authors: Schwarz
authors: Christin
authors: C
authors: Schröder
authors: Alexander
authors: A
authors: Hassel
authors: Wolfgang
authors: W
authors: Bömicke
authors: Peter
authors: P
authors: Rammelsberg
mesh_terms: D002484:Cementation / Q000379:methods; D002516:Ceramics / Q000737:chemistry; D003442:Crowns; D003738:Dental Cements / Q000737:chemistry / Q000145:classification; D019250:Dental Implants, Single-Tooth; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003801:Dental Veneers; D005260:Female; D005500:Follow-Up Studies; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery; D008437:Maxilla / Q000601:surgery; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008875:Middle Aged; D012189:Retrospective Studies; D013499:Surface Properties; D016019:Survival Analysis; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003738:Dental Cements; D003764:Dental Materials; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; C023506:Glass ceramics; D015040:Zirconium; C028541:zirconium oxide