title: Bond strength of selected composite resin-cements to zirconium-oxide ceramic.
abstract: OBJECTIVE
  The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements.
  
  
  METHODS
  130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001).
  
  
  RESULTS
  Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-W<0.001). The worst techniques were Lava TM + sandblasting + Silane + Rely X; Lava TM + sandblasting + Silane + Multilink and Lava TM + CoJet + silane + Multilink. Adhesive failure (separation of cement and ceramic) was produced at a lesser force than cohesive failure (fracture of cement) (p-value M-W<0.001). Electron microscopy confirmed that the surface treatments modified the zirconium-oxide ceramic, creating a more rough and retentive surface, thus providing an improved micromechanical interlocking between the cement and the ceramic.
  
  
  CONCLUSIONS
  Best results were provided by dual-polymerizing cements associated with sandblasting or silica coating and a bonding agent containing MDP.
authors.affiliation: Occlusion and Prosthodontic Teaching Unit, Department of Stomatology, University of Valencia, Edificio Clínica Odontológica, C/ Gascó Oliag No 1, 46010 Valencia, Spain. juanluis.romanrodriguez@gmail.com
authors.forename: Juan-Luis
authors.initials: JL
authors.lastname: Román-Rodríguez
authors.forename: Antonio
authors.initials: A
authors.lastname: Fons-Font
authors.forename: Vicente
authors.initials: V
authors.lastname: Amigó-Borrás
authors.forename: María
authors.initials: M
authors.lastname: Granell-Ruiz
authors.forename: David
authors.initials: D
authors.lastname: Busquets-Mataix
authors.forename: Rubén-Agustín
authors.initials: RA
authors.lastname: Panadero
authors.forename: Maria-Fernanda
authors.initials: MF
authors.lastname: Solá-Ruiz
mesh_terms: D002516:Ceramics; D003188:Composite Resins; D001840:Dental Bonding; D003764:Dental Materials; D008422:Materials Testing; D019279:Resin Cements; D015040:Zirconium
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D019279:Resin Cements; D015040:Zirconium; C028541:zirconium oxide