title: A prospective 10-year study of metal ceramic single crowns and fixed dental prosthesis retainers in private practice settings.
abstract: BACKGROUND
  Metal ceramic restorations are widely used in prosthodontics, but long-term data on their clinical performance in private practice settings based on prospective trials are sparse.
  
  
  OBJECTIVE
  This clinical trial was designed to provide realistic long-term survival rates for different outcomes related to tooth loss, crown loss, and metal ceramic defect.
  
  
  METHODS
  Ninety-five participants were provided with 190 noble metal ceramic single crowns and 138 participants with 276 fixed dental prosthesis retainer crowns on vital posterior teeth. Follow-up examinations were scheduled 2 weeks after insertion, annually up to 8 years, and after 10 years. Kaplan-Meier survival analyses, Mantel-Cox logrank tests, and Cox regression analyses were conducted.
  
  
  RESULTS
  Because of variations in the time of the last examinations, the maximum observation period was 12.1 years. For the primary outcome 'loss of crown or tooth', the Kaplan-Meier survival rate was 94.3% ±1.8% (standard error) at 8.0 years (last outcome event) for single crowns and 94.4% ±1.5% at 11.0 years for fixed dental prosthesis retainer crowns. The difference between the survival functions was not significant (P>.05). For the secondary outcome 'metal ceramic defect', the survival rate was 88.8% ±3.2% at 11.0 years for single crowns and 81.7% ±3.5% at 11.0 years for fixed dental prosthesis retainer crowns. In Cox regression models, the only significant covariates for the outcome event 'metal ceramic defect' were bruxism in the medical history (single crowns) and signs and symptoms of bruxism (fixed dental prosthesis retainer crowns) with hazard ratios of 3.065 (95% CI 1.063 - 8.832) and 2.554 (95% CI 1.307 - 4.992).
  
  
  CONCLUSIONS
  Metal ceramic crowns provided in private practice settings show good longevity. Bruxism appears to indicate a risk for metal ceramic defects.
authors.affiliation: Department of Prosthetic Dentistry, Carl Gustav Carus Faculty of Medicine, Technical University of Dresden Dental School, Dresden, Germany. bernd.reitemeier@uniklinikum-dresden.de
authors.forename: Bernd
authors.initials: B
authors.lastname: Reitemeier
authors.forename: Kristina
authors.initials: K
authors.lastname: Hänsel
authors.forename: Christian
authors.initials: C
authors.lastname: Kastner
authors.forename: Anke
authors.initials: A
authors.lastname: Weber
authors.forename: Michael H
authors.initials: MH
authors.lastname: Walter
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000538:Aluminum Silicates / Q000737:chemistry; D002012:Bruxism / Q000150:complications; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D003781:Denture Retention / Q000295:instrumentation*; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D016876:Metal Ceramic Alloys / Q000737:chemistry*; D008875:Middle Aged; D010165:Palladium / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D011446:Prospective Studies; D012834:Silver / Q000737:chemistry; D016019:Survival Analysis; D016388:Tooth Loss / Q000145:classification; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000538:Aluminum Silicates; D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D017680:Potassium Compounds; D003776:Dental Porcelain; C016447:feldspar; D012834:Silver; D010984:Platinum; D010165:Palladium