title: Clinical evaluation of marginal fit of a new experimental all-ceramic system before and after cementation.
abstract: OBJECTIVE
  The purpose of this in vivo study was to evaluate the marginal fit of inlay and crown abutments for fixed partial dentures (FPD) made from a new all-ceramic material.
  
  
  METHODS
  Sixteen patients were selected for the study. After abutment preparation, impressions were made and master dies were fabricated. FPDs were made with the experimental heat-pressed lithium-disilicate glass-ceramic following the manufacturer's recommendations. At random, one abutment of each FPD was chosen for evaluation (11 crown and 8 inlay abutments). Impressions of the restoration margins were taken before and after adhesive cementation. Replicas of the abutment margins were investigated by SEM. The marginal discrepancies were evaluated in sections of 200 microm. The highest value of each section was applied, and the mean of all sections of each replica was used for statistical analysis.
  
  
  RESULTS
  The median of the marginal discrepancies before cementation was 96 microm for crowns and 89 microm for inlays. After adhesive cementation, the median increased for crowns to 130 microm and for inlays to 92 microm, a significant increase in the marginal discrepancies caused by cementation for crowns, but not for inlays. There were no significant differences between the discrepancies of crowns and inlays before or after cementation.
  
  
  CONCLUSIONS
  The maximum marginal discrepancies found in this study were between 50 and 265 microm before cementation and between 70 and 285 microm after cementation, with no significant differences between the means for crowns and inlays. Adhesive cementation caused a significant increase of the marginal discrepancies for crown, but not inlay, abutments.
authors.affiliation: Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian Albrechts University, University Hospital Schleswig-Holstein, Campus Kiel, Germany. swolfart@proth.uni-kiel.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Wolfart
authors.forename: Stefan Martin
authors.initials: SM
authors.lastname: Wegner
authors.forename: Adham
authors.initials: A
authors.lastname: Al-Halabi
authors.forename: Matthias
authors.initials: M
authors.lastname: Kern
mesh_terms: D002484:Cementation; D002516:Ceramics / Q000737:chemistry*; D003442:Crowns; D000044:Dental Abutments; D003737:Dental Cavity Preparation; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain / Q000737:chemistry; D017267:Dental Prosthesis Design; D003830:Denture, Partial, Fixed; D006801:Humans; D007284:Inlays; D018020:Lithium Compounds / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016628:Replica Techniques; D013499:Surface Properties; D019231:Tooth Preparation, Prosthodontic
chemical_list: C118557:Empress 2; D018020:Lithium Compounds; D003776:Dental Porcelain