title: Microtensile bond strengths of composite to dentin treated with desensitizer products.
abstract: OBJECTIVE
  This study was designed to analyze the influence of desensitizing procedures on dentin bond strength.
  
  
  METHODS
  Forty bovine incisors were used, divided into four groups (n = 10): G1: control; G2: Gluma Desensitizer (Heraeus Kulzer); G3: Oxa-Gel (Art-Dent); G4: low-intensity laser (MMOptics). The buccal surface was wet ground flat with 180-, 400- and 600-grit silicon carbide abrasive paper to expose midcoronal dentin and create a uniform surface. After the application of the desensitizing agents to the exposed dentin, the specimens were etched with 35% phosphoric acid for 30 s, and an adhesive (Single Bond) was applied and light cured. A 4-mm high crown of composite resin (Filtek Z250) was then built up. Specimens were trimmed to an hourglass shape with cross sections of 1 mm2. Each specimen was individually fractured by a microtensile testing machine at a crosshead speed of 0.5 mm/min. The data, recorded in MPa, were analyzed with one-way ANOVA and the Duncan test (p = 0.05).
  
  
  RESULTS
  Specimens treated with dentin desensitizers (except Gluma) yielded significantly lower mean bond strengths than nontreated control specimens. The mean values in MPa (+/- SD) were: G1: 13.4 (6.2); G2: 13.2 (4.8); G3: 7.15 (4.3); G4: 7.21 (4.6).
  
  
  CONCLUSIONS
  Among the desensitizing agents studied, only Gluma Desensitizer did not detrimentally influence the bond strength values. It is a useful material for dentin desensitization.
authors.affiliation: Department of Dentistry, Special Laboratory of Lasers in Dentistry, University of São Paulo, Brazil. acca@usp.br
authors.forename: Ana Cecília Corrêa
authors.initials: AC
authors.lastname: Aranha
authors.forename: Adonis De Santi
authors.initials: Ade S
authors.lastname: Siqueira Junior
authors.forename: Larissa Maria Assad
authors.initials: LM
authors.lastname: Cavalcante
authors.forename: Luiz André Freire
authors.initials: LA
authors.lastname: Pimenta
authors.forename: Giselle Maria
authors.initials: GM
authors.lastname: Marchi
mesh_terms: D000134:Acid Etching, Dental; D000818:Animals; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002417:Cattle; D002482:Cellulose / Q000031:analogs & derivatives / Q000627:therapeutic use; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003804:Dentin / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D003807:Dentin Sensitivity / Q000188:drug therapy* / Q000532:radiotherapy; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005976:Glutaral / Q000627:therapeutic use; D007834:Lasers; D008422:Materials Testing; D008689:Methacrylates / Q000627:therapeutic use; D008855:Microscopy, Electron, Scanning; D010070:Oxalates / Q000627:therapeutic use; D010756:Phosphoric Acids / Q000737:chemistry; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D008689:Methacrylates; D010070:Oxalates; D010756:Phosphoric Acids; C111486:gluma desensitizer; C470050:oxa-gel; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D002482:Cellulose; C030242:phosphoric acid; D005976:Glutaral