title: In vitro shear bond strength of two self-adhesive resin cements to zirconia.
abstract: BACKGROUND
  Although the use of anatomic-contour zirconia restorations has expanded in the recent past, disagreement still exists as to reliable cementation techniques and materials.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to compare the immediate and artificially aged shear bond strength of 2 commercially available self-adhesive resin cements to zirconia: one with silica coating and silanation as a zirconia surface treatment and the other contained a phosphate monomer, which eliminated the need for a separate primer.
  
  
  METHODS
  Sixty composite resin rods (2.5 mm in diameter and 3 mm in length) were fabricated from a nano-optimized composite resin by using a polypropylene mold, then light polymerized with a light-emitting diode. zirconia plates (10×10×4mm) were sectioned from an yttrium-stabilized zirconia puck, sintered, and then mounted in autopolymerizing acrylic resin custom tray material. Composite resin rods were cemented to the zirconia plates with 2 different cements. The surface treatment of zirconia followed the manufacturers' instructions for each cement. The specimens were tested for shear bond strength at 3 aging conditions: immediate, after 24 hours of moist storage, and after 30 days of moist storage with 10000 thermocycles. Specimens were loaded to failure in a universal testing machine, and the data were analyzed with 2-way ANOVA (α=.05). Weibull parameters (modulus and characteristic strength) also were calculated for each group.
  
  
  RESULTS
  Two-way ANOVA revealed that only the aging condition significantly affected the bond strength to zirconia. The cement and the interaction of the cement and aging did not significantly affect the shear bond strength to zirconia. The highest bond strength for both cements was achieved at 24 hours, whereas the lowest bond strength values were recorded in the immediate groups.
  
  
  CONCLUSIONS
  No significant differences in bond strength to zirconia were observed between a cement with a silane priming step and an methacryloxydecyl dihydrogen phosphate-containing cement without a separate primer. Aging had a significant effect on the shear bond strength of the 2 self-adhesive resin cements to zirconia.
authors.affiliation: Clinical Assistant Professor, Department of Restorative Dentistry, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY. Electronic address: dqeblawi@buffalo.edu.
authors.forename: Dana M
authors.initials: DM
authors.lastname: Qeblawi
authors.affiliation: Senior Research Scientist, Department of Restorative Dentistry, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Marc
authors.initials: M
authors.lastname: Campillo-Funollet
authors.affiliation: Professor, Department of Restorative Dentistry, School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Muñoz
mesh_terms: D000179:Acrylates / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D055117:Curing Lights, Dental / Q000145:classification; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry; D058105:Polymerization; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000179:Acrylates; D020099:Coated Materials, Biocompatible; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; C483701:Rely X Unicem; D019279:Resin Cements; D012821:Silanes; C501891:Tetric EvoCeram; C499362:yttria stabilized tetragonal zirconia; D014867:Water; D015019:Yttrium; D012822:Silicon Dioxide; C069749:methacryloyloxydecyl dihydrogen phosphate; C040415:heliobond; D015040:Zirconium