title: Effect of Silane Reaction Time on the Repair of a Nanofilled Composite Using Tribochemical Treatment.
abstract: OBJECTIVE
  To investigate the influence of silane reaction time on the repair strength of an aged nanofilled composite and to characterize the bonding mechanism.
  
  
  METHODS
  Nanofilled composite disks (n = 110, Filtek Supreme XT) were aged for 90 days in water. After tribochemical treatment (CoJet-Sand), the specimens were assigned to 5 groups (n = 22), primed with silane (Espe-Sil), and left to react for 1, 2, 3, 4, and 5 min. A thin layer of adhesive (Visio-Bond) was applied and a new composite with the same dimension was placed and cured. Non-aged specimens immediately layered and cured using the incremental technique served as controls. After aging (30 days in water plus 5000 thermal cycles), the interface was subjected to a shearing force until failure. Failure mode was evaluated under a stereomicroscope and scanning electron microscopy (SEM). Additional aged and treated surfaces were evaluated for morphology as well as elemental and molecular composition using SEM/EDX and ATR-FTIR.
  
  
  RESULTS
  The mean shear bond strength (SBS) of the repaired specimens was 53.9 ± 8.6 MPa, with no significant difference among the various reaction times, but significantly lower compared to the control (88.1 ± 12.5 MPa). Tribochemical treatment created an irregular surface morphology with particles imbedded in the aged surface. Interfacial SEM/EDX analysis showed a 5-μm non-uniform high atomic number zone rich in Al and Si.
  
  
  CONCLUSIONS
  Tribochemical treatments for repairing composite using a short silane reaction period (1 min) are equally effective as the prolonged reaction periods (2 to 5 min), yielding interfacial shear strength of ~60% of unrepaired material.
authors.forename: Raphael
authors.initials: R
authors.lastname: Pilo
authors.forename: Tamar
authors.initials: T
authors.lastname: Brosh
authors.forename: Valery
authors.initials: V
authors.lastname: Geron
authors.forename: Shifra
authors.initials: S
authors.lastname: Levartovsky
authors.forename: George
authors.initials: G
authors.lastname: Eliades
mesh_terms: D000535:Aluminum / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C474035:Filtek Supreme; D019279:Resin Cements; D012821:Silanes; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate; C081713:Visio-Bond; D000535:Aluminum; D012825:Silicon