title: Marginal discrepancy of all-ceramic crowns cemented on implant abutments.
abstract: OBJECTIVE
  The purpose of this investigation was to determine the mean marginal discrepancy of all-ceramic crowns cemented on implant abutments.
  
  
  METHODS
  Five Brånemark CeraOne abutments were connected to implant fixtures embedded in acrylic resin blocks. The marginal discrepancy was measured using a video camera connected to a digitizing board at four locations on each abutment for five samples in each of the following groups: all-ceramic caps (caps), all-ceramic crowns (crowns), and all-ceramic crowns cemented with zinc phosphate cement (cemented crowns).
  
  
  RESULTS
  The mean marginal discrepancies were as follows: caps, 99.0 micrometers (SD, 16); crowns, 117.8 micrometers (SD, 20); and cemented crowns, 168.8 micrometers (SD, 23). Statistically significant differences were found between all three groups at the 99% level of confidence. In addition there were two significant differences between abutments.
  
  
  CONCLUSIONS
  Subgingival marginal discrepancies of the magnitude measured in this study have been shown to cause periodontal problems. It is probable that the marginal discrepancy of CeraOne restorations, as tested, can be improved. Efforts should be made to enhance the marginal accuracy of these restorations.
authors.affiliation: Department of Restorative and Prosthetic Dentistry, College of Dentistry, University of Saskatchewan, Saskatoon, Canada.
authors.forename: J K
authors.initials: JK
authors.lastname: Sutherland
authors.forename: R W
authors.initials: RW
authors.lastname: Loney
authors.forename: S
authors.initials: S
authors.lastname: Syed
mesh_terms: D000704:Analysis of Variance; D002484:Cementation; D003442:Crowns; D000044:Dental Abutments; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D006801:Humans; D007284:Inlays; D003765:Models, Dental; D015036:Zinc Phosphate Cement
chemical_list: D003776:Dental Porcelain; D015036:Zinc Phosphate Cement