title: Reinforcement of bond strength of self-etching orthodontic adhesive.
abstract: OBJECTIVE
  To determine the reinforcement of bond strength of a self-etching system by applying a pretreatment agent.
  
  
  METHODS
  Sixty extracted human premolars were used in this study. The enamel surfaces were treated with four pretreatment agents-phosphoric acid, polyacrylic acid, citric acid, and ammonium hexafluorosilicate (SiF)-and were examined under a scanning electron microscope. Afterward, orthodontic brackets were bonded with a self-etching adhesive system (n  =  10 for each agent), and shear bond strength was measured through a debonding process. The adhesive remnant index (ARI) was also assessed.
  
  
  RESULTS
  Enamel surfaces treated with polyacrylic acid seemed almost the same as intact enamel. Treatment with SiF induced slight shallow depressions compared with the intact enamel. On the other hand, enamel surfaces treated with citric acid and phosphoric acid showed severe etching patterns. All pretreatments increased the bond strength, but SiF-treated specimens revealed the greatest strength (12.201 ± 1.048 MPa), followed by polyacrylic acid (12.030 ± 2.103 MPa). The control group with no pretreatment showed the least strength (9.078 ± 1.678 MPa). All pretreatments increased ARI score compared with the control group.
  
  
  CONCLUSIONS
  Surface conditioning before bracket adhesion could reinforce the bond strength of the self-etching adhesive system, resulting in a more reliable bonding system.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopedics, The Tokushima University Medical and Dental Hospital, Tokushima, Japan. horiu@dent.tokushima-u.ac.jp
authors.forename: Shinya
authors.initials: S
authors.lastname: Horiuchi
authors.forename: Shingo
authors.initials: S
authors.lastname: Kuroda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hiasa
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suge
authors.forename: Seitaro
authors.initials: S
authors.lastname: Saku
authors.forename: Kenichi
authors.initials: K
authors.lastname: Hamada
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuo
authors.forename: Kenzo
authors.initials: K
authors.lastname: Asaoka
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D001840:Dental Bonding / Q000379:methods*; D017005:Dental Debonding; D003743:Dental Enamel / Q000187:drug effects*; D003799:Dental Stress Analysis; D006801:Humans; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D018709:Statistics, Nonparametric
chemical_list: C519484:Beauty Ortho Bond; D019279:Resin Cements