title: Joining dental ceramic layers with glass.
abstract: OBJECTIVE
  Test the hypothesis that glass-bonding of free-form veneer and core ceramic layers can produce robust interfaces, chemically durable and esthetic in appearance and, above all, resistant to delamination.
  
  
  METHODS
  Layers of independently produced porcelains (NobelRondo™ Press porcelain, Nobel BioCare AB and Sagkura Interaction porcelain, Elephant Dental) and matching alumina or zirconia core ceramics (Procera alumina, Nobel BioCare AB, BioZyram yttria stabilized tetragonal zirconia polycrystal, Cyrtina Dental) were joined with designed glasses, tailored to match thermal expansion coefficients of the components and free of toxic elements. Scanning electron microprobe analysis was used to characterize the chemistry of the joined interfaces, specifically to confirm interdiffusion of ions. Vickers indentations were used to drive controlled corner cracks into the glass interlayers to evaluate the toughness of the interfaces.
  
  
  RESULTS
  The glass-bonded interfaces were found to have robust integrity relative to interfaces fused without glass, or those fused with a resin-based adhesive.
  
  
  CONCLUSIONS
  The structural integrity of the interfaces between porcelain veneers and alumina or zirconia cores is a critical factor in the longevity of all-ceramic dental crowns and fixed dental prostheses.
authors.affiliation: Department of Materials Science and Engineering, University of Maryland, College Park, MD 20742-2115, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Saied
authors.forename: I K
authors.initials: IK
authors.lastname: Lloyd
authors.forename: W K
authors.initials: WK
authors.lastname: Haller
authors.forename: B R
authors.initials: BR
authors.lastname: Lawn
mesh_terms: D000537:Aluminum Oxide; D003442:Crowns; D001840:Dental Bonding; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D003801:Dental Veneers; D055119:Elastic Modulus; D005898:Glass / Q000737:chemistry; D006244:Hardness; D008422:Materials Testing; D058989:Vitrification; D015019:Yttrium; D015040:Zirconium
chemical_list: C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium; D000537:Aluminum Oxide