title: Influence of Pre-etching Times on Fatigue Strength of Self-etch Adhesives to Enamel.
abstract: OBJECTIVE
  To use shear bond strength (SBS) and shear fatigue strength (SFS) testing to determine the influence of phosphoric acid pre-etching times prior to application of self-etch adhesives on enamel bonding.
  
  
  METHODS
  Two single-step self-etch universal adhesives (Prime&Bond Elect and Scotchbond Universal), a conventional single-step self-etch adhesive (G-ӕnial Bond), and a conventional two-step self-etch adhesive (OptiBond XTR) were used. The SBS and SFS were obtained with phosphoric acid pre-etching for 3, 10, or 15 s prior to application of the adhesives, and without pre-etching (0 s) as a control. A staircase method was used to determine the SFS with 10 Hz frequency for 50,000 cycles or until failure occurred. The mean demineralization depth for each treated enamel surface was also measured using a profilometer.
  
  
  RESULTS
  For all the adhesives, the groups with pre-etching showed significantly higher SBS and SFS than groups without pre-etching. However, there was no significant difference in SBS and SFS among groups with > 3 s of preetching. In addition, although the groups with pre-etching showed significantly deeper demineralization depths than groups without pre-etching, there was no significant difference in depth among groups with > 3 s of pre-etching.
  
  
  CONCLUSIONS
  Three seconds of phosphoric acid pre-etching prior to application of self-etch adhesive can enhance enamel bonding effectiveness.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takamizawa
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Barkmeier
authors.forename: Akimasa
authors.initials: A
authors.lastname: Tsujimoto
authors.forename: Hajime
authors.initials: H
authors.lastname: Endo
authors.forename: Kenji
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Robert L
authors.initials: RL
authors.lastname: Erickson
authors.forename: Mark A
authors.initials: MA
authors.lastname: Latta
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D017438:Bisphenol A-Glycidyl Methacrylate; D003743:Dental Enamel; D003764:Dental Materials; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D011109:Polymethacrylic Acids; D019279:Resin Cements; D033081:Shear Strength; D013997:Time Factors
chemical_list: D003764:Dental Materials; C498353:G-Bond; D008689:Methacrylates; C092987:Optibond; D011109:Polymethacrylic Acids; C103500:Prime & Bond; D019279:Resin Cements; D017438:Bisphenol A-Glycidyl Methacrylate; C041330:Scotchbond