title: A retrospective analysis of 102 zirconia single crowns with knife-edge margins.
abstract: BACKGROUND
  Clinical reports of feldspathic porcelain veneered-zirconia crowns placed on teeth with knife-edge marginal finish lines have recently been presented but with data available for only a limited number of crowns in the anterior maxilla.
  
  
  OBJECTIVE
  This retrospective study evaluated the clinical success and survival of feldspathic porcelain veneered-zirconia crowns fabricated with knife-edge margins in a private practice.
  
  
  METHODS
  One hundred and two teeth (51 anterior, 51 posterior) were prepared with knife-edge margins and restored with feldspathic porcelain veneered-zirconia crowns. The modified California Dental Association (CDA) criteria were used to clinically evaluate subjects recalled between May and December 2010. Data were analyzed with descriptive statistics.
  
  
  RESULTS
  The mean follow-up time was 20.9 months (SD, 13.6; range, 10-72). One tooth had to be extracted because of an endodontic problem not related with the restoration, 2 crowns had minor chipping of the veneering porcelain, while no crowns exhibited fracture of the zirconia core.
  
  
  CONCLUSIONS
  In this retrospective evaluation, feldspathic porcelain veneered-zirconia crowns with knife-edge margins provided clinical performance similar to that reported with other margin designs.
authors.affiliation: Eastman Institute for Oral Health, School of Medicine and Dentistry, University of Rochester, Rochester, NY 14620, USA. Carlo_Poggio@URMC.Rochester.edu
authors.forename: Carlo E
authors.initials: CE
authors.lastname: Poggio
authors.forename: Riccardo
authors.initials: R
authors.lastname: Dosoli
authors.forename: Carlo
authors.initials: C
authors.lastname: Ercoli
mesh_terms: D017076:Computer-Aided Design; D003442:Crowns; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D006801:Humans; D012189:Retrospective Studies; D019231:Tooth Preparation, Prosthodontic / Q000379:methods*; D015040:Zirconium
chemical_list: D003776:Dental Porcelain; D015040:Zirconium; C028541:zirconium oxide