title: In vivo preservation of the hybrid layer by chlorhexidine.
abstract: Host-derived proteases have been reported to degrade the collagen matrix of incompletely-resin-infiltrated dentin. This study tested the hypothesis that interfacial degradation of resin-dentin bonds may be prevented or delayed by the application of chlorhexidine (CHX), a matrix metalloproteinase inhibitor, to dentin after phosphoric acid-etching. Contralateral pairs of resin-bonded Class I restorations in non-carious third molars were kept under intra-oral function for 14 months. Preservation of resin-dentin bonds was assessed by microtensile bond strength tests and TEM examination. In vivo bond strength remained stable in the CHX-treated specimens, while bond strength decreased significantly in control teeth. Resin-infiltrated dentin in CHX-treated specimens exhibited normal structural integrity of the collagen network. Conversely, progressive disintegration of the fibrillar network was identified in control specimens. Auto-degradation of collagen matrices can occur in resin-infiltrated dentin, but may be prevented by the application of a synthetic protease inhibitor, such as chlorhexidine.
authors.affiliation: Department of Restorative Dentistry, Dental Materials Area, University of Campinas, Piracicaba School of Dentistry, Piracicaba/SP, Brazil.
authors.forename: M R O
authors.initials: MR
authors.lastname: Carrilho
authors.forename: S
authors.initials: S
authors.lastname: Geraldeli
authors.forename: F
authors.initials: F
authors.lastname: Tay
authors.forename: M F
authors.initials: MF
authors.lastname: de Goes
authors.forename: R M
authors.initials: RM
authors.lastname: Carvalho
authors.forename: L
authors.initials: L
authors.lastname: Tjäderhane
authors.forename: A F
authors.initials: AF
authors.lastname: Reis
authors.forename: J
authors.initials: J
authors.lastname: Hebling
authors.forename: A
authors.initials: A
authors.lastname: Mazzoni
authors.forename: L
authors.initials: L
authors.lastname: Breschi
authors.forename: D
authors.initials: D
authors.lastname: Pashley
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry*; D002710:Chlorhexidine / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D024022:Fibrillar Collagens / Q000648:ultrastructure; D006801:Humans; D008422:Materials Testing; D061965:Matrix Metalloproteinase Inhibitors; D046529:Microscopy, Electron, Transmission; D010756:Phosphoric Acids / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; D024022:Fibrillar Collagens; D061965:Matrix Metalloproteinase Inhibitors; D010756:Phosphoric Acids; D011480:Protease Inhibitors; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; C030242:phosphoric acid; D002710:Chlorhexidine