title: Effect of surface modification on the bond strength between zirconia and resin cement.
abstract: OBJECTIVE
  This study aimed to evaluate the micro push-out (μ-PO) bond strength between zirconia and resin cement after addition of zirconia particles to increase the surface roughness.
  
  
  METHODS
  Y-TZP zirconia specimens in three experimental groups were subjected to Y-TZP particle deposition via dipping into the milling residue suspension at different times prior to the sintering process. The dipping procedure was repeated twice for each specimen in group B, six times in group C, and ten times in group D. The specimens subjected to airborne-particle abrasion (110 μm Al2 O3, Rocatec Pre) acted as the control group (group A). All of the specimens were then bonded using adhesive resin cement (RelyX Ultimate). A μ-PO test was used to determine the bond strength values. One-way ANOVA at a 5% confidence level was performed for data analysis. Optical microscopy and scanning electron microscopy (SEM) were used to evaluate the failure modes and surface structure.
  
  
  RESULTS
  Y-TZP particle deposition did not have a significant effect on the bond strength of the resin cement to zirconia specimens when compared to the control (p = 0.141). Higher bond strength values were observed in groups C and D than in control. The surface layer presented blister-like porosities with openings of various diameters ranging between 2 and 4 μm.
  
  
  CONCLUSIONS
  Y-TZP particle deposition after dipping six and ten times did not improve the mean bond strength statistically but presented surface topography that may be favorable for increased micromechanical retention for adhesive resin cement.
  
  
  CONCLUSIONS
  Y-TZP particle deposition may create a more retentive surface than airborne-particle abrasion for adhesive bonding between zirconia surface and resin cement.
authors.affiliation: Department of Prosthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey.
authors.forename: Ferhan
authors.initials: F
authors.lastname: Egilmez
authors.affiliation: Department of Prosthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey.
authors.forename: Gulfem
authors.initials: G
authors.lastname: Ergun
authors.affiliation: Department of Prosthodontics, Gazi University Faculty of Dentistry, Ankara, Turkey.
authors.forename: Isil
authors.initials: I
authors.lastname: Cekic-Nagas
authors.affiliation: Department of Biomaterials Science and Turku Clinical Biomaterials Centre, Institute of Dentistry, University of Turku, Turku, Finland.
authors.forename: Pekka K
authors.initials: PK
authors.lastname: Vallittu
authors.affiliation: Dental Materials Unit, Center for Dental and Oral Medicine-Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, University of Zurich, Zurich, Switzerland.
authors.forename: Mutlu
authors.initials: M
authors.lastname: Ozcan
authors.affiliation: Department of Biomaterials Science and Turku Clinical Biomaterials Centre, Institute of Dentistry, University of Turku, Turku, Finland.
authors.forename: Lippo V J
authors.initials: LVJ
authors.lastname: Lassila
mesh_terms: D000268:Adhesiveness; D000537:Aluminum Oxide / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D017076:Computer-Aided Design; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D006358:Hot Temperature; D006801:Humans; D006813:Humidity; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D058105:Polymerization; D016062:Porosity; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D015019:Yttrium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; C528569:Rely-X; D019279:Resin Cements; C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D015040:Zirconium; D000537:Aluminum Oxide
keywords: Y-TZP zirconia; adhesive resin cement; micro push-out bond test; milling residue suspension