In vivo preservation of the hybrid layer by chlorhexidine.
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.
Carrilho
M R O
MR
Department of Restorative Dentistry, Dental Materials Area, University of Campinas, Piracicaba School of Dentistry, Piracicaba/SP, Brazil.
Geraldeli
S
S
Tay
F
F
de Goes
M F
MF
Carvalho
R M
RM
Tjäderhane
L
L
Reis
A F
AF
Hebling
J
J
Mazzoni
A
A
Breschi
L
L
Pashley
D
D
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
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