title: Clinical assessment of high-strength all-ceramic crowns.
abstract: BACKGROUND
  All-ceramic crowns are being used extensively. Little data are available on their clinical performance.
  
  
  OBJECTIVE
  This study evaluated the clinical performance of In-Ceram (Vita Zahnfabrik) crowns.
  
  
  METHODS
  Forty-one patients (16 men, 25 women; mean age 47.3 years, range 18 to 77 years) were examined with a total of 80 In-Ceram all-ceramic crowns fabricated at the University of Iowa College of Dentistry from 1994 to 1997. The percentage distribution for crowns included: 67% anterior single crowns, 26% posterior single crowns, 6% anterior implant crowns, and 1% posterior implant crowns. This study documented the integrity of the junction between crown and tooth, color match to adjacent teeth, secondary dental caries, wear of crown and opposing dentition, and visible cracks in the crown. Alpha, Bravo, and Charlie ratings were assigned with a modified USPHS criteria. The patients were also surveyed with respect to oral hygiene and satisfaction of treatment. Estimations of 4-year success rates and corresponding confidence intervals were calculated by fitting a constant hazard function model with the SAS procedure GENMOD.
  
  
  RESULTS
  Marginal integrity for 88% of artificial crowns was rated Alpha or Bravo. Shade match for 99% was Bravo or better. Only 1% of the crowns were carious, and 1 crown exhibited occlusal wear. One premolar crown had a small fracture of veneering porcelain. One molar crown was remade after core fracture. All patients (100%) expressed satisfaction with their crowns. The estimated 4-year success rates (Alpha or Bravo), with 95% confidence intervals in parentheses were calculated as: 83.5% (65.7%-94.6%) for marginal integrity, 95.8% (82.9%-99.8%) for shade match, and 95.5% (81.6%-99.7%) for secondary caries, 100% (88%-100%) for wear, and 100% (88%-100%) for cracks.
authors.affiliation: University of Iowa, College of Dentistry, Iowa City, Iowa 52242, USA. debra-haselton@uiowa.edu
authors.forename: D R
authors.initials: DR
authors.lastname: Haselton
authors.forename: A M
authors.initials: AM
authors.lastname: Diaz-Arnold
authors.forename: S L
authors.initials: SL
authors.lastname: Hillis
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000537:Aluminum Oxide / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003116:Color; D016001:Confidence Intervals; D003442:Crowns; D000044:Dental Abutments; D003731:Dental Caries / Q000209:etiology; D019250:Dental Implants, Single-Tooth; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure; D019554:Dental Restoration Wear; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009910:Oral Hygiene; D017060:Patient Satisfaction; D011176:Post and Core Technique; D016016:Proportional Hazards Models; D013499:Surface Properties; D019217:Tooth Attrition / Q000209:etiology; D016896:Treatment Outcome
chemical_list: D003776:Dental Porcelain; C070870:In-Ceram; D000537:Aluminum Oxide