title: Fiber post etching with hydrogen peroxide: effect of concentration and application time.
abstract: BACKGROUND
  Etching is necessary to expose the fibers and enable both mechanical and chemical bonding of the resin core to the fiber post. This study evaluated the effect of concentration and application time of hydrogen peroxide on the surface topography and bond strength of glass fiber posts to resin cores.
  
  
  METHODS
  Fiber posts were etched with 24% or 50% hydrogen peroxide for 1, 5, or 10 min (n = 10). Posts without any treatment were used as a control. After etching, the posts were silanated and adhesive resin was applied. The posts were positioned into a mold to allow a self-cured resin core to be inserted. The post/resin assembly was serially sectioned into five beams that were subjected to a tensile bond strength test. Data were subjected to two-way ANOVA and Tukey test (α = 0.05). The surface topography was analyzed using scanning electronic microscopy.
  
  
  RESULTS
  Non-etched post presents a relatively smooth surface without fiber exposure. Application of hydrogen peroxide increased the surface roughness and exposed the fibers. All experimental conditions yielded similar bond strength values that were higher than those obtained in the control group.
  
  
  CONCLUSIONS
  Both 24% and 50% hydrogen peroxide exposure increased the bond strength of resin to the posts, irrespective of the application time.
authors.affiliation: Department of Operative Dentistry and Dental Materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil. murilomenezes@foufu.ufu.br
authors.forename: Murilo
authors.initials: M
authors.lastname: de Sousa Menezes
authors.forename: Ellyne Cavalcanti
authors.initials: EC
authors.lastname: Queiroz
authors.forename: Paulo Vinícius
authors.initials: PV
authors.lastname: Soares
authors.forename: André Luis
authors.initials: AL
authors.lastname: Faria-e-Silva
authors.forename: Carlos José
authors.initials: CJ
authors.lastname: Soares
authors.forename: Luis Roberto Marcondes
authors.initials: LR
authors.lastname: Martins
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods*; D004853:Epoxy Resins / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D016877:Oxidants / Q000008:administration & dosage / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation; D011791:Quartz / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D003188:Composite Resins; D004853:Epoxy Resins; D008689:Methacrylates; D016877:Oxidants; D011109:Polymethacrylic Acids; D019279:Resin Cements; D012821:Silanes; C009753:fiberglass; D011791:Quartz; C020946:triethylene glycol dimethacrylate; C100742:All-Bond 2; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D006861:Hydrogen Peroxide