title: Bond strength of metal brackets bonded to a silica-based ceramic with light-cured adhesive : Influence of various surface treatment methods.
abstract: OBJECTIVE
  The purpose of this work was to evaluate the effects of several surface treatment methods on the shear bond strengths of metal brackets bonded to a silica-based ceramic with a light-cured adhesive.
  
  
  METHODS
  Silica-based ceramic (IPS Classic(®)) with glazed surfaces was cut into discs that were used as substrates. A total of 80 specimens were randomly divided into four groups according to the method used: 9.6 % hydrofluoric acid (group 1), 9.6 % hydrofluoric acid (HF) + silane coupling agent (group 2), sandblasting (aluminum trioxide, 50 μm) + silane (group 3), and tribochemical silica coating (CoJet™ sand, 30 μm) + silane (group 4). Brackets were bonded to the treated specimens with a light-cure adhesive (Transbond XT, 3 M Unitek). Shear bond strength was tested after bracket bonding, and the Adhesive Remnant Index (ARI) scores were quantified after debonding.
  
  
  RESULTS
  Group 4 showed the highest bond strength (12.3 ± 1.0 MPa), which was not significantly different from that of group 3 (11.6 ± 1.2 MPa, P > 0.05); however, the bond strength of group 4 was substantially higher than that of group 2 (9.4 ± 1.1 MPa, P < 0.05). The shear bond strength of group 1 (3.1 ± 0.6 MPa, P< 0.05) was significantly lower than that of the other groups.
  
  
  CONCLUSIONS
  Shear bond strengths exceeded the optimal range of ideal bond strength for clinical practice, except for the isolated HF group. HF acid etching followed by silane was the best suited method for bonding on IPS Classic(®). Failure modes in the sandblasting and silica-coating groups revealed signs of damaged ceramic surfaces.
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Room 213, Building No. 1, 639 Zhi-Zao-Ju Road, Shanghai, China.
authors.forename: Zhe-Chen
authors.initials: ZC
authors.lastname: Zhang
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Room 213, Building No. 1, 639 Zhi-Zao-Ju Road, Shanghai, China.
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Qian
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Room 213, Building No. 1, 639 Zhi-Zao-Ju Road, Shanghai, China.
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Yang
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Room 213, Building No. 1, 639 Zhi-Zao-Ju Road, Shanghai, China.
authors.forename: Qi-Ping
authors.initials: QP
authors.lastname: Feng
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Orthodontics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Room 213, Building No. 1, 639 Zhi-Zao-Ju Road, Shanghai, China. drgangshen@163.com.
authors.forename: Gang
authors.initials: G
authors.lastname: Shen
mesh_terms: D000268:Adhesiveness / Q000528:radiation effects; D002516:Ceramics / Q000737:chemistry* / Q000528:radiation effects; D045662:Dental Etching / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry; D003799:Dental Stress Analysis; D008027:Light; D055115:Light-Curing of Dental Adhesives / Q000379:methods*; D008670:Metals / Q000737:chemistry* / Q000528:radiation effects; D016910:Orthodontic Brackets; D011829:Radiation Dosage; D019279:Resin Cements / Q000737:chemistry* / Q000528:radiation effects; D033081:Shear Strength / Q000528:radiation effects; D012822:Silicon Dioxide / Q000737:chemistry / Q000528:radiation effects; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength / Q000528:radiation effects
chemical_list: D003764:Dental Materials; D008670:Metals; D019279:Resin Cements; D012822:Silicon Dioxide
keywords: Sandblasting; Shear bond strength; Silane; Silica coating; Surface conditioning