title: Chlorhexidine stabilizes the adhesive interface: a 2-year in vitro study.
abstract: OBJECTIVE
  This study evaluated the role of endogenous dentin MMPs in auto-degradation of collagen fibrils within adhesive-bonded interfaces. The null hypotheses tested were that adhesive blends or chlorhexidine digluconate (CHX) application does not modify dentin MMPs activity and that CHX used as therapeutic primer does not improve the stability of adhesive interfaces over time.
  
  
  METHODS
  Zymograms of protein extracts from human dentin powder incubated with Adper Scotchbond 1XT (SB1XT) on untreated or 0.2-2% CHX-treated dentin were obtained to assay dentin MMPs activity. Microtensile bond strength and interfacial nanoleakage expression of SB1XT bonded interfaces (with or without CHX pre-treatment for 30s on the etched surface) were analyzed immediately and after 2 years of storage in artificial saliva at 37 degrees C.
  
  
  RESULTS
  Zymograms showed that application of SB1XT to human dentin powder increases MMP-2 activity, while CHX pre-treatment inhibited all dentin gelatinolytic activity, irrespective from the tested concentration. CHX significantly lowered the loss of bond strength and nanoleakage seen in acid-etched resin-bonded dentin artificially aged for 2 years.
  
  
  CONCLUSIONS
  The study demonstrates the active role of SB1XT in dentin MMP-2 activation and the efficacy of CHX inhibition of MMPs even if used at low concentration (0.2%).
authors.affiliation: Department of Biomedicine, Unit of Dental Sciences and Biomaterials, University of Trieste, Via Stuparich 1, Trieste, Italy. lbreschi@units.it
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Breschi
authors.forename: Annalisa
authors.initials: A
authors.lastname: Mazzoni
authors.forename: Fernando
authors.initials: F
authors.lastname: Nato
authors.forename: Marcela
authors.initials: M
authors.lastname: Carrilho
authors.forename: Erika
authors.initials: E
authors.lastname: Visintini
authors.forename: Leo
authors.initials: L
authors.lastname: Tjäderhane
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ruggeri
authors.forename: Franklin R
authors.initials: FR
authors.lastname: Tay
authors.forename: Elettra De Stefano
authors.initials: Ede S
authors.lastname: Dorigo
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
mesh_terms: D000704:Analysis of Variance; D000891:Anti-Infective Agents, Local / Q000737:chemistry* / Q000627:therapeutic use; D002710:Chlorhexidine / Q000494:pharmacology*; D001840:Dental Bonding; D003763:Dental Leakage; D003799:Dental Stress Analysis; D003804:Dentin / Q000201:enzymology*; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000032:analysis / Q000378:metabolism*; D061965:Matrix Metalloproteinase Inhibitors; D019279:Resin Cements / Q000494:pharmacology; D018709:Statistics, Nonparametric; D013718:Tensile Strength
chemical_list: D000891:Anti-Infective Agents, Local; D017220:Dentin-Bonding Agents; D061965:Matrix Metalloproteinase Inhibitors; D019279:Resin Cements; C041330:Scotchbond; D020778:Matrix Metalloproteinase 2; D002710:Chlorhexidine