title: Orthodontic bracket bonding to glazed full-contour zirconia.
abstract: OBJECTIVE
  This study evaluated the effects of different surface conditioning methods on the bond strength of orthodontic brackets to glazed full-zirconia surfaces.
  
  
  METHODS
  Glazed zirconia (except for the control, Zirkonzahn Prettau) disc surfaces were pre-treated: PO (control), polishing; BR, bur roughening; PP, cleaning with a prophy cup and pumice; HF, hydrofluoric acid etching; AA, air abrasion with aluminum oxide; CJ, CoJet-Sand. The surfaces were examined using profilometry, scanning electron microscopy, and electron dispersive spectroscopy. A zirconia primer (Z-Prime Plus, Z) or a silane primer (Monobond-S, S) was then applied to the surfaces, yielding 7 groups (PO-Z, BR-Z, PP-S, HF-S, AA-S, AA-Z, and CJ-S). Metal bracket-bonded specimens were stored in water for 24 hr at 37℃, and thermocycled for 1,000 cycles. Their bond strengths were measured using the wire loop method (n = 10).
  
  
  RESULTS
  Except for BR, the surface pre-treatments failed to expose the zirconia substructure. A significant difference in bond strengths was found between AA-Z (4.60 ± 1.08 MPa) and all other groups (13.38 ± 2.57 - 15.78 ± 2.39 MPa, p < 0.05). For AA-Z, most of the adhesive remained on the bracket.
  
  
  CONCLUSIONS
  For bracket bonding to glazed zirconia, a simple application of silane to the cleaned surface is recommended. A zirconia primer should be used only when the zirconia substructure is definitely exposed.
authors.affiliation: Department of Medical and Biological Engineering, Graduate School, Kyungpook National University, Daegu, Korea.
authors.forename: Ji-Young
authors.initials: JY
authors.lastname: Kwak
authors.affiliation: Department of Dental Laboratory Technology, Daegu Health College, Daegu, Korea.
authors.forename: Hyo-Kyung
authors.initials: HK
authors.lastname: Jung
authors.affiliation: Department of Medical and Biological Engineering, Graduate School, Kyungpook National University, Daegu, Korea.
authors.forename: Il-Kyung
authors.initials: IK
authors.lastname: Choi
authors.affiliation: Department of Dental Biomaterials, School of Dentistry, Kyungpook National University, Daegu, Korea.
authors.forename: Tae-Yub
authors.identifier: 0000-0002-9998-3099
authors.initials: TY
authors.lastname: Kwon
keywords: Adhesive; Bonding; Orthodontic brackets; Zirconia