title: Influence of surface treatments and resin cement selection on bonding to densely-sintered zirconium-oxide ceramic.
abstract: OBJECTIVE
  To evaluate the effect of surface conditioning on the microtensile bond strength of zirconium-oxide ceramic to dual-cured resin cements.
  
  
  METHODS
  Eighteen cylinder-shaped zirconium-oxide ceramic blocks (Cercon Zirconia, Dentsply) were treated as follows: (1) Sandblasting with 125 microm aluminum-oxide (Al(2)O(3)) particles; (2) tribochemical silica coating using 50 microm Al(2)O(3) particles modified by silica; (3) no treatment. Each ceramic cylinder was duplicated in composite resin (Tetric Evo Ceram, Ivoclar-Vivadent) using a silicon mold. Composite cylinders were bonded to conditioned ceramics using: (1) Calibra (Densply Caulk); (2) Clearfil Esthetic Cement (Kuraray); (3) Rely x Unicem (3M ESPE). After 24h bonded specimens were cut into microtensile sticks that were loaded in tension until failure. Data were analyzed using two-way ANOVA and Student-Newman-Keuls test for multiple comparisons (p<0.05). Failure mode was recorded and the interfacial morphology of debonded specimens was observed using a scanning electron microscope (SEM). Surface topography and ceramic average surface roughness were analyzed under an atomic force microscope (AFM).
  
  
  RESULTS
  Significant changes in zirconia surface roughness occurred after sandblasting (p<0.001). Bond strength of Clearfil cement to zirconia was significantly higher than that of Rely x Unicem and Calibra, regardless of the surface treatment (p<0.001). When using Calibra, premature failures occurred in non-treated and silica coated zirconia surfaces.
  
  
  CONCLUSIONS
  The phosphate monomer-containing luting system (Clearfil Esthetic Cement) is recommended to bond zirconia ceramics and surface treatments are not necessary.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, University Complutense of Madrid, Madrid, Spain.
authors.forename: Raquel Castillo
authors.initials: RC
authors.lastname: de Oyagüe
authors.forename: Francesca
authors.initials: F
authors.lastname: Monticelli
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
authors.forename: Estrella
authors.initials: E
authors.lastname: Osorio
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D045662:Dental Etching; D003776:Dental Porcelain / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D015040:Zirconium / Q000737:chemistry*
chemical_list: C433205:Calibra; D003188:Composite Resins; C483701:Rely X Unicem; D019279:Resin Cements; C501891:Tetric EvoCeram; C530542:clearfil esthetic cement; D003776:Dental Porcelain; D012822:Silicon Dioxide; D015040:Zirconium; D000537:Aluminum Oxide; C028541:zirconium oxide