title: A systematic review of the clinical performance of CAD/CAM single-tooth restorations.
abstract: OBJECTIVE
  This systematic review sought to determine the long-term clinical survival rates of single-tooth restorations fabricated with computer-aided design/computer-assisted manufacture (CAD/CAM) technology, as well as the frequency of failures depending on the CAD/CAM system, the type of restoration, the selected material, and the luting agent.
  
  
  METHODS
  An electronic search from 1985 to 2007 was performed using two databases: Medline/PubMed and Embase. Selected keywords and well-defined inclusion and exclusion criteria guided the search. All articles were first reviewed by title, then by abstract, and subsequently by a full text reading. Data were assessed and extracted by two independent examiners. The pooled results were statistically analyzed and the overall failure rate was calculated by assuming a Poisson-distributed number of events. In addition, reported failures were analyzed by CAD/CAM system, type of restoration, restorative material, and luting agent.
  
  
  RESULTS
  From a total of 1,957 single-tooth restorations with a mean exposure time of 7.9 years and 170 failures, the failure rate was 1.75% per year, estimated per 100 restoration years (95% CI: 1.22% to 2.52%). The estimated total survival rate after 5 years of 91.6% (95% CI: 88.2% to 94.1%) was based on random-effects Poisson regression analysis.
  
  
  CONCLUSIONS
  Long-term survival rates for CAD/CAM single-tooth Cerec 1, Cerec 2, and Celay restorations appear to be similar to conventional ones. No clinical studies or randomized clinical trials reporting on other CAD/CAM systems currently used in clinical practice and with follow-up reports of 3 or more years were found at the time of the search.
authors.affiliation: Advanced Graduate Prosthodontics Program, Department of Restorative Dentistry and Biomaterials Sciences, Harvard School of Dental Medicine (HSDM), Boston, Massachusetts, USA. julia.wittneben@zmk.unibe.ch
authors.forename: Julia-Gabriela
authors.initials: JG
authors.lastname: Wittneben
authors.forename: Robert F
authors.initials: RF
authors.lastname: Wright
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Weber
authors.forename: German O
authors.initials: GO
authors.lastname: Gallucci
mesh_terms: D017076:Computer-Aided Design; D003442:Crowns; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent; D003801:Dental Veneers; D006801:Humans; D016019:Survival Analysis