title: Single crowns with CAD/CAM-fabricated copings from titanium: 6-year clinical results.
abstract: BACKGROUND
  Computer-aided design/computer-aided manufacturing (CAD/CAM) titanium ceramic restorations were developed with the potential for replacing expensive, high noble metal ceramic restorations. However, little information exists about the clinical performance of CAD/CAM titanium ceramic single crowns.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate CAD/CAM titanium ceramic single crowns after 6 years in function.
  
  
  METHODS
  A total of 41 crowns were fabricated for 21 patients. The titanium copings were CAD/CAM milled (Everest CAD/CAM system), with an even thickness of 0.5 mm and veneered with low-fusing porcelain (Vita Titanium Porcelain) in the powder-build-up technique. All the crowns were cemented with zinc phosphate. The participants were recalled at 12, 24, 36, 48, 60, and 72 months after cementation to document any mechanical and biologic complications and to measure the periodontal parameters, such as probing depth, bleeding on probing, and the plaque index. The success and survival rates were calculated according to the Kaplan-Meier analysis.
  
  
  RESULTS
  After 6 years of clinical service, 12 mechanical complications and 1 biologic complication were found, which resulted in a success rate of 67.8%. The cumulative survival rate of the crowns was 91.3% after 6 years. At the end of the follow-up period, the probing depth was 3.21 mm, the percentile of surface with bleeding on probing was 25, and the plaque index was 0.37. No secondary caries or decementation was detected during the 6-year observation period.
  
  
  CONCLUSIONS
  The clinical performance of the CAD/CAM titanium-ceramic crowns after 6 years was poor because of veneering porcelain problems. Recent CAD software with tools to design proper copings might improve the clinical success.
authors: Assistant Professor, Department of Prosthetic Dentistry, University School of Dental Medicine, Martin Luther University, Halle, Germany. Electronic address: jeremias.hey@medizin.uni-halle.de.
authors: Jeremias
authors: J
authors: Hey
authors: Assistant Professor, Department of Prosthodontics, Munich Dental School, Ludwig Maximilian University, Munich, Germany.
authors: Florian
authors: F
authors: Beuer
authors: Resident, Department of Prosthetic Dentistry, University School of Dental Medicine, Martin Luther University, Halle, Germany.
authors: Tobias
authors: T
authors: Bensel
authors: Assistant Professor, Department of Prosthetic Dentistry, University School of Dental Medicine, Martin Luther University, Halle, Germany.
authors: Arne F
authors: AF
authors: Boeckler
mesh_terms: D000328:Adult; D000368:Aged; D002484:Cementation / Q000379:methods; D017076:Computer-Aided Design; D003442:Crowns; D018772:Dental Marginal Adaptation; D003774:Dental Plaque Index; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D003801:Dental Veneers; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008875:Middle Aged; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification; D011446:Prospective Studies; D013499:Surface Properties; D016019:Survival Analysis; D014025:Titanium / Q000737:chemistry*; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D015036:Zinc Phosphate Cement; C074226:Harvard Cement; D014025:Titanium