title: In vitro evaluation of shear bond strengths of resin to densely-sintered high-purity zirconium-oxide ceramic after long-term storage and thermal cycling.
abstract: BACKGROUND
  The few available studies on the resin bond to zirconium-oxide ceramic recommend airborne-particle abrasion and modified resin luting agents containing adhesive monomers for superior and long-term durable bond strengths. It is unknown whether this regimen can also be successfully applied to the intaglio surface of a commercial zirconia-based all-ceramic system.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate and compare bond strengths of different bonding/silane coupling agents and resin luting agents to zirconia ceramic before and after artificial aging.
  
  
  METHODS
  Composite cylinders (2.9 mm x 3.0 mm) were bonded to airborne-particle-abraded intaglio surfaces of Procera AllZirkon specimens (n=80) with either Panavia F (PAN) or Rely X ARC (REL) resin luting agents after pretreatment with Clearfil SE Bond/ Porcelain Bond Activator (Group SE). In another group, Rely X ARC was used with its bonding/silane coupling agent (Single Bond/Ceramic Primer, Group SB). PAN without any bonding/silane agent (Group NO) was the control. Subgroups of 10 specimens were stored in distilled water for either 3 or 180 days before shear bond strength was tested. One hundred eighty-day-old specimens were repeatedly thermal cycled for 12,000 cycles between 5 and 60 degrees C with a 15-second dwell time. Data were analyzed with 1- and 2-way analysis of variance and the Tukey multiple comparisons test (alpha=.05). Failure modes were examined under original magnification x25.
  
  
  RESULTS
  After 3 days, SE-REL (25.15 +/- 3.48 MPa) and SE-PAN (20.14 +/- 2.59 MPa) groups had significantly superior mean shear bond strengths (P=.0007) compared with either NO-PAN (17.36 +/- 3.05 MPa) or SB-REL (16.90 +/- 7.22 MPa). SE-PAN, NO-PAN, and SB-REL groups were not significantly different. Artificial aging significantly reduced bond strengths. After 180-day storage, SE-PAN (16.85 +/- 3.72 MPa), and SE-REL (15.45 +/- 3.79 MPa) groups demonstrated significantly higher shear bond strengths than NO-PAN (9.45 +/- 5.06 MPa) or SB-REL (1.08 +/- 1.85 MPa) groups. The modes of failure varied among 3-day groups but were 100% adhesive at the ceramic surfaces after artificial aging.
  
  
  CONCLUSIONS
  Artificial aging significantly reduced bond strength. A bonding/silane coupling agent containing an adhesive phosphate monomer can achieve superior long-term shear bond strength to airborne-particle- abraded Procera AllZirkon restorations with either one of the 2 resin luting agents tested.
authors.affiliation: School of Dentistry, Louisiana State University Health Sciences Center, New Orleans, LA 70122, USA. mblatz@lsuhsc.edu
authors.forename: Markus B
authors.initials: MB
authors.lastname: Blatz
authors.forename: Avishai
authors.initials: A
authors.lastname: Sadan
authors.forename: Javier
authors.initials: J
authors.lastname: Martin
authors.forename: Brien
authors.initials: B
authors.lastname: Lang
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate; D001840:Dental Bonding; D003775:Dental Polishing; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D004356:Drug Storage; D008422:Materials Testing; D011092:Polyethylene Glycols; D011109:Polymethacrylic Acids; D019279:Resin Cements; D033081:Shear Strength; D012821:Silanes; D013499:Surface Properties; D015040:Zirconium
chemical_list: C438843:Panavia-Fluoro; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; D012821:Silanes; D003776:Dental Porcelain; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D015040:Zirconium; C028541:zirconium oxide