title: Influence of water storage on fatigue strength of self-etch adhesives.
abstract: OBJECTIVE
  The purpose of this study was to determine enamel and dentin bond durability after long-term water storage using self-etch adhesives.
  
  
  METHODS
  Two single step self-etch adhesives (SU, Scotchbond Universal and GB, G-ӕnial Bond) and a two-step self-etch adhesive (OX, OptiBond XTR) were used. The shear bond strength (SBS) and shear fatigue strength (FS) of the enamel and dentin were obtained with and without phosphoric acid pre-etching prior to application of the adhesives. The specimens were stored in distilled water at 37 °C for 24 h, 6 months, and one year. A staircase method was used to determine the FS using a frequency of 10 Hz for 50,000 cycles or until failure occurred.
  
  
  RESULTS
  The SBS and FS of enamel bonds were significantly higher with pre-etching, when compared to no pre-etching for the same water storage period. The FS of dentin bonds with pre-etching tended to decrease relative to no pre-etching at the same storage period. For the one year storage period, SU and GB with pre-etching showed significantly lower FS values than the groups without pre-etching.
  
  
  CONCLUSIONS
  The influence of water storage on FS of the self-etch adhesives was dependent on the adhesive material, storage period and phosphoric acid pre-etching of the bonding site.
  
  
  CONCLUSIONS
  Phosphoric acid pre-etching of enamel improves the effectiveness of self-etch adhesive systems. Inadvertent contact of phosphoric acid on dentin appears to reduce the ability of self-etch adhesives to effectively bond resin composite materials.
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan. Electronic address: takamizawa.toshiki@nihon-u.ac.jp.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takamizawa
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Barkmeier
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Akimasa
authors.initials: A
authors.lastname: Tsujimoto
authors.affiliation: Department of Diagnostic Sciences, Creighton University School of Dentistry, USA.
authors.forename: Donal D
authors.initials: DD
authors.lastname: Scheidel
authors.affiliation: Section of Operative Dentistry, University of Nebraska, Lincoln, Nebraska, USA.
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Watanabe
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA.
authors.forename: Robert L
authors.initials: RL
authors.lastname: Erickson
authors.affiliation: Department of General Dentistry, Creighton University School of Dentistry, Omaha, NE, USA.
authors.forename: Mark A
authors.initials: MA
authors.lastname: Latta
authors.affiliation: Department of Operative Dentistry, Nihon University School of Dentistry, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Miyazaki
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D001840:Dental Bonding / Q000379:methods; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000648:ultrastructure; D045662:Dental Etching; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003804:Dentin / Q000000981:diagnostic imaging / Q000187:drug effects / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008963:Molar / Q000187:drug effects; D010756:Phosphoric Acids / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D014867:Water / Q000737:chemistry*
chemical_list: D003738:Dental Cements; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D014867:Water
keywords: Fatigue strength; Long-term water storage; Phosphoric acid pre-etching; Self-etch adhesive