title: Five-year Effects of Chlorhexidine on the In Vitro Durability of Resin/Dentin Interfaces.
abstract: OBJECTIVE
  To evaluate the effect of an acid containing 2% chlorhexidine (Ac/CHX) or a 2% CHX aqueous solution (Aq/CHX) on the immediate and 5-year bonding properties of resin/dentin interfaces produced by two adhesives. The presence of CHX in these interfaces was also evaluated under micro-Raman spectroscopy.
  
  
  METHODS
  Forty-two molars were ground to expose a flat dentin surface. In the control group, the surfaces were etched with conventional phosphoric acid, and Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied. In Ac/CHX, an acid containing 2% CHX was applied after adhesive application. In the Aq/CHX group, an aqueous solution of 2% CHX was applied for 60 s after etching. After placing the restoration, specimens were prepared and tested using the microtensile bond strength test (μTBS, 0.5 mm/min) immediately or after 5 years. For nanoleakage (NL), specimens at each period were immersed in silver nitrate solution and examined by EDX-SEM. In addition, specimens at each period underwent examination for CHX using micro-Raman spectroscopy. Data were submitted to appropriate statistical analysis (a=0.05).
  
  
  RESULTS
  After 5 years, NL was more pronounced in the control than in the Ac/CHX or Aq/CHX (p<0.001). Significant reductions in the μTBS were observed for all groups; however, they were more pronounced for the control (p<0.001). CHX was still present in the hybrid layers Ac/CHX or Aq/CHX groups after 5 years.
  
  
  CONCLUSIONS
  The use of a 2% chlorhexidine-containing acid or the application of an aqueous CHX primer may increase the long-term stability of resin/dentin interfaces.
authors.forename: Alessandro D
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Viviane
authors.initials: V
authors.lastname: Hass
authors.forename: Mario Felipe
authors.initials: MF
authors.lastname: Gutierrez
authors.forename: Issis Virginia
authors.initials: IV
authors.lastname: Luque-Martinez
authors.forename: Anna
authors.initials: A
authors.lastname: Szezs
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Stanislawczuk
authors.forename: Matheus Coelho
authors.initials: MC
authors.lastname: Bandeca
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000145:classification; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D004791:Enzyme Inhibitors / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D016622:Silver Staining; D013052:Spectrometry, X-Ray Emission; D013059:Spectrum Analysis, Raman; D013718:Tensile Strength; D013997:Time Factors
chemical_list: C554641:Adper single bond 2; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D004791:Enzyme Inhibitors; D010756:Phosphoric Acids; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D019279:Resin Cements; C030242:phosphoric acid; C010882:chlorhexidine gluconate; D002710:Chlorhexidine