title: Bond durability of different resin cements to caries-affected dentin under simulated intrapulpal pressure.
abstract: OBJECTIVE
  To evaluate the durability of the bond of different resin cement systems to normal dentin (ND) and caries-affected dentin (CAD) with and without simulated intrapulpal pressure (IPP).
  
  
  METHODS
  Molars with midcoronal caries were used. Occlusal enamel was cut to expose both dentin substrates (ND and CAD). Dentin substrates were differentiated using visual, tactile, caries-detecting dye, and dye-permeability methods. Prepared crown segments were equally divided according to the tested resin cement systems: etch-and-rinse resin cement, self-etch resin cement containing methacryloyloxydecyl dihydrogen phosphate (MDP), and self-adhesive resin cement. In addition to the dentin substrates and the resin cement types, the effect of application/storage conditions (with or without simulated IPP and with or without thermocycling) were tested. A microtensile bond strength test was done using a universal testing machine. Failure modes were determined using a scanning electron microscope.
  
  
  RESULTS
  Etch-and-rinse resin cement strength values were significantly affected by the difference in the dentin substrates as well as the different application/storage conditions. Self-etch adhesive containing MDP bonded equally to ND and CAD and remained stable under all tested conditions. Self-adhesive resin cement revealed a similar bond to ND and CAD; however, its values were the lowest, especially when IPP and thermocycling were combined. Mixed failure was the predominant failure mode.
  
  
  CONCLUSIONS
  Etch-and-rinse resin cement was sensitive to dentin substrate and application/storage conditions. Resin cement with self-etch adhesive containing MDP revealed more reliable bonding to ND/CAD even when IPP and thermocycling were combined. The bonding of the self-adhesive resin cement could not compete with other resin cements.
authors.forename: M F
authors.initials: MF
authors.lastname: Mohamed
authors.forename: H A
authors.initials: HA
authors.lastname: El Deeb
authors.forename: I E
authors.initials: IE
authors.lastname: Gomaa
authors.forename: E H
authors.initials: EH
authors.lastname: Mobarak
mesh_terms: D001840:Dental Bonding / Q000379:methods* / Q000592:standards; D003731:Dental Caries / Q000601:surgery*; D003799:Dental Stress Analysis; D003804:Dentin / Q000601:surgery; D017220:Dentin-Bonding Agents / Q000592:standards / Q000627:therapeutic use*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000601:surgery; D019279:Resin Cements / Q000592:standards / Q000627:therapeutic use*; D013718:Tensile Strength
chemical_list: D017220:Dentin-Bonding Agents; D019279:Resin Cements