title: Enamel and dentin bond strength, interfacial ultramorphology and fluoride ion release of self-etching adhesives during a pH-cycling regime.
abstract: OBJECTIVE
  This study evaluated the effects of pH cycling on fluoride release and bond strength of two self-etching adhesive systems to both enamel and dentin. The ultramorphology of the interfaces produced by the adhesive systems were also analyzed.
  
  
  METHODS
  The buccal surfaces of bovine incisors were flattened to expose enamel and dentin, which were bonded with either Clearfil Protect Bond (CPB) or One-Up Bond F Plus (OBP). The bonded samples were prepared for microtensile bond strength (μTBS) testing, fluoride ion release, and transmission electron microscopy. pH cycling comprised demineralization (8 h/day) and remineralization (16 h/day) cycles for 8 days. The μTBS data were analyzed by two-way ANOVA, while fluoride release was analyzed using the Friedman and Wilcoxon tests.
  
  
  RESULTS
  The adhesives presented similar bond strengths to enamel. However, the dentin bond strength of CPB was higher than that of OBP. pH cycling did not influence enamel or dentin μTBS. The amount of fluoride released from the bonded enamel and dentin was low and varied among the groups. The morphological evaluation showed that the thickness of the dentin hybrid layers was similar for both adhesives.
  
  
  CONCLUSIONS
  The pH-cycling regime did not affect enamel or dentin bond strengths. In enamel, both the self-etching adhesives tested presented similar bond strengths, but in dentin, Clearfil Protect Bond showed higher dentin bonding than One-Up Bond F Plus.
authors.forename: Cristiane Franco
authors.initials: CF
authors.lastname: Pinto
authors.forename: Paulo Moreira
authors.initials: PM
authors.lastname: Vermelho
authors.forename: Thaiane Rodrigues
authors.initials: TR
authors.lastname: Aguiar
authors.forename: Adriana Franco
authors.initials: AF
authors.lastname: Paes Leme
authors.forename: Marcelo Tavares de
authors.initials: MT
authors.lastname: Oliveira
authors.forename: Evelise Machado de
authors.initials: EM
authors.lastname: Souza
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cavalli
authors.forename: Marcelo
authors.initials: M
authors.lastname: Giannini
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000818:Animals; D002327:Cariostatic Agents / Q000737:chemistry*; D002417:Cattle; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D019279:Resin Cements / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D017001:Tooth Demineralization / Q000503:physiopathology; D014089:Tooth Remineralization
chemical_list: D002327:Cariostatic Agents; C503075:Clearfil Protect Bond; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C446260:One-Up-Bond F; D019279:Resin Cements; D005459:Fluorides