title: A systematic review of the survival and complication rates of all-ceramic and metal-ceramic reconstructions after an observation period of at least 3 years. Part I: Single crowns.
abstract: OBJECTIVE
  The objective of this systematic review was to assess the 5-year survival rates of all-ceramic single crowns and to compare it with the survival rates of metal-ceramic crowns and to describe the incidence of biological and technical complications.
  
  
  METHODS
  An electronic Medline and Dental Global Publication Research System search complemented by manual searching was conducted to identify prospective and retrospective cohort studies on all-ceramic and metal-ceramic crowns with a mean follow-up time of at least 3 years. Patients had to have been examined clinically at the follow-up visit. Assessment of the identified studies and data abstraction was performed independently by two reviewers. Annual failure rates were analyzed using standard and random-effects Poisson regression models to obtain summary estimates of survival proportions.
  
  
  RESULTS
  The search provided 3473 titles and 177 abstracts. Full-text analysis was performed for 86 articles, resulting in 34 studies that met the inclusion criteria. In meta-analysis, the 5-year survival of all-ceramic crowns was estimated at 93.3% (95% confidence interval (CI): 91.1%-95%) and 95.6% (95% CI: 92.4%-97.5%) for metal-ceramic crowns. All-ceramic crowns were also analyzed according to the material utilized. Densely sintered alumina (Procera technique) crowns showed the highest 5-year survival rate of 96.4%, followed by reinforced glass-ceramic crowns (Empress technique) and InCeram-crowns with survival rates of 95.4% and 94.5%, respectively. A significantly lower survival rate of 87.5% was calculated for glass-ceramic crowns after 5 years. All-ceramic crowns were also grouped and analyzed regarding the position in the mouth. All four types of all-ceramic crowns showed lower survival rates when seated on posterior teeth. Moreover, for glass-ceramic crowns (84.4%) and InCeram-crowns (90.4%), this difference reached statistical significance (P = 0.009, P = 0.028).
  
  
  CONCLUSIONS
  Based on the present systematic review, all-ceramic crowns, when used for anterior teeth, showed survival rates at 5 years comparable to those seen for metal-ceramic crowns. When used for posterior teeth, the survival rates at 5 years of densely sintered alumina crowns (94.9%) and reinforced glass-ceramic crowns (93.7%) were similar to those obtained for metal-ceramic crowns. Furthermore, lower survival rates of 90.4% and 84.4% can be expected for InCeram crowns and glass-ceramic crowns when utilized for premolars and molars.
authors.affiliation: Department of Periodontology and Fixed Prosthodontics, University of Berne School of Dental Medicine, Berne, Switzerland. bjarni.pjetursson@zmk.unibe.ch
authors.forename: Bjarni E
authors.initials: BE
authors.lastname: Pjetursson
authors.forename: Irena
authors.initials: I
authors.lastname: Sailer
authors.forename: Marcel
authors.initials: M
authors.lastname: Zwahlen
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
mesh_terms: D002516:Ceramics; D015331:Cohort Studies; D003442:Crowns / Q000009:adverse effects*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent; D006801:Humans; D008670:Metals; D008963:Molar; D011446:Prospective Studies; D012189:Retrospective Studies
chemical_list: D008670:Metals