title: Bonding to zirconia using a new surface treatment.
abstract: OBJECTIVE
  Selective infiltration etching (SIE) is a newly developed surface treatment used to modify the surface of zirconia-based materials, rendering them ready for bonding to resin cements. The aim of this study was to evaluate the zirconia/resin bond strength and durability using the proposed technique.
  
  
  METHODS
  Fifty-four zirconia discs were fabricated and divided into three groups (n = 18) according to their surface treatment: as-sintered surface (control group), airborne-particle abrasion (50-mum aluminum oxide), and SIE group. The zirconia discs were bonded to preaged composite resin discs using a light-polymerized adhesive resin (Panavia F 2.0). The zirconia/resin bond strength was evaluated using microtensile bond strength test (MTBS), and the test was repeated after each of the following intervals of accelerated artificial aging (AA): thermocycling (10,000 cycles between 5 and 55 degrees C), 4 weeks of water storage (37 degrees C), and finally 26 weeks of water storage (37 degrees C). Silver nitrate nanoleakage analysis was used to assess the quality of zirconia/resin interface. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 18, alpha= 0.05)
  
  
  RESULTS
  There were significant differences in the MTBS values between the three test groups at each of the test intervals (p < 0.001). AA resulted in reduction in the bond strength of the as-sintered and the particle-abraded groups (5.9 MPa and 27.4, MPa, respectively). Reduction in the bond strength of these groups was explained by the observed nanoleakage across the zirconia/resin interface. The bond strength of the SIE specimens was stable after completion of AA (51.9 MPa), which also demonstrated a good seal against silver nitrate penetration across the zirconia/resin interface.
  
  
  CONCLUSIONS
  SIE established a strong, stable, and durable bond to zirconia substrates. Conservative resin-bonded zirconia restorations are now possible using this new technique.
authors.affiliation: Dental Biomaterials Department, Faculty of Dentistry, Alexandria University, Egypt. Bluemarline_1@yahoo.com
authors.forename: Moustafa N
authors.initials: MN
authors.lastname: Aboushelib
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Feilzer
authors.forename: Cornelis J
authors.initials: CJ
authors.lastname: Kleverlaan
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry; D002197:Capillary Action; D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods*; D045662:Dental Etching / Q000379:methods*; D003763:Dental Leakage / Q000145:classification; D003764:Dental Materials / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D005898:Glass / Q000737:chemistry; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D044367:Phase Transition; D019279:Resin Cements / Q000737:chemistry; D016622:Silver Staining; D012995:Solubility; D013314:Stress, Mechanical; D013499:Surface Properties; D013500:Surface Tension; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D044366:Transition Temperature; D014867:Water / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C444701:Filtek Z250; C438843:Panavia-Fluoro; D019279:Resin Cements; D014867:Water; D015040:Zirconium; D000537:Aluminum Oxide; D006858:Hydrofluoric Acid; C028541:zirconium oxide