title: Effect of different adhesive systems and laser treatment on the shear bond strength of bleached enamel.
abstract: OBJECTIVE
  This study determined the shear bond strength of a nanohybrid composite resin to bleached enamel immediately or 15 days later using different adhesive systems and laser application.
  
  
  METHODS
  One hundred and forty enamel specimens were prepared from human molar teeth and bleached either with 16% carbamide peroxide (CP) or 30% CP according to the manufacturer's (Vivastyle/Vivadent) recommendations. After bleaching treatments specimens were divided into two groups according to the treatment time of the adhesive procedures: immediately or 15 days after the bleaching treatments. The four groups were then divided into five subgroups due to the surface treatments: using a two-step self-etching adhesive (AdheSe, Ivoclar Vivadent G, Schaan, Liechtenstein) or a two-step etch and rinse adhesive (Excite, Ivoclar Vivadent G, Schaan, Liechtenstein) and application of laser prior to adhesive procedures or not. After adhesive procedures nanohybrid composite resin cylinders of 4 mm x 2 mm (Tetric Evo Ceram/Vivadent) were bonded to the enamel surfaces. All specimens were subjected to shear bond strength test after thermocycling and 24h of storage in water. Data were analyzed statistically.
  
  
  RESULTS
  Mann-Whitney U-test analysis showed no significant difference in the mean bond strength values of enamel bleached with either 16% CP or 30% CP (p>0.05). There was no difference between the groups bonded immediately or 15 days after bleaching (p>0.05). Application of the etch and rinse adhesive after 15 days showed the highest bond strength values, whereas self-etching adhesive and laser application showed the lowest values in both bleaching treatments.
  
  
  CONCLUSIONS
  The results suggested that following the bleaching treatments, the use of etch and rinse adhesive system may provide higher bond strengths than self-etching adhesive and laser application.
authors.affiliation: Hacettepe University, School of Dentistry, Department of Restorative Dentistry, Sihhiye 06100, Ankara, Turkey.
authors.forename: Sevil
authors.initials: S
authors.lastname: Gurgan
authors.forename: Tugba
authors.initials: T
authors.lastname: Alpaslan
authors.forename: Arlin
authors.initials: A
authors.lastname: Kiremitci
authors.forename: Filiz Yalcin
authors.initials: FY
authors.lastname: Cakir
authors.forename: Esra
authors.initials: E
authors.lastname: Yazici
authors.forename: Jale
authors.initials: J
authors.lastname: Gorucu
mesh_terms: D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D000077463:Carbamide Peroxide; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000187:drug effects / Q000528:radiation effects / Q000648:ultrastructure*; D003764:Dental Materials / Q000737:chemistry; D004338:Drug Combinations; D006801:Humans; D053844:Lasers, Solid-State; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D010545:Peroxides / Q000008:administration & dosage / Q000627:therapeutic use; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use; D014867:Water / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; C489662:AdheSE cement; D003188:Composite Resins; D003764:Dental Materials; D004338:Drug Combinations; C420130:Excite cement; D008689:Methacrylates; D016877:Oxidants; D010545:Peroxides; D019279:Resin Cements; C501891:Tetric EvoCeram; D014867:Water; D000077463:Carbamide Peroxide; D014508:Urea