title: Effect of the flavonoid epigallocatechin-3-gallate on resin-dentin bond strength.
abstract: OBJECTIVE
  To evaluate the effect of dentin pretreatment with epigallocatechin-3-gallate solution on the preservation of the resin/dentin interface with etch-and-rinse adhesives.
  
  
  METHODS
  Thirty extracted human molars were prepared to expose the dentin surface and divided into 5 groups according to the pretreatment solution. Dentin surfaces were etched (35% phosphoric acid for 15 s), rinsed, and air dried. Dentin was rewetted either with distilled water, 3 different epigallocatechin-3-gallate solutions (EGCG; 0.02%, 0.1%, or 0.5% w/v), or 2% chlorhexidine digluconate solution for 60 s. Adper Single Bond 2 was applied and a subsequent 5-mm-thick resin crown was built up. Bonded teeth were longitudinally sectioned to obtain sticks with a cross-sectional area of 1.0 mm2. Half of the specimens were immediately tested, while the remaining specimens were tested after storage in 3 mMol/l sodium azide solution at 37°C for six months. The mode of fracture was examined. Bond strength values were analyzed with ANOVA and Student-Newman-Keuls tests.
  
  
  RESULTS
  After 24 h of storage, mean bond strengths of 0.5% EGCG were significantly lower than those found for the other groups (p < 0.05), except for 0.02% EGCG (p > 0.05). Resin-dentin bond strengths after 6 months were not significantly different among the experimental groups (p > 0.05). Storage in water for 6 months resulted in a significant decrease in bond strength for the water control group only (p < 0.05). The bond strengths of the experimental groups remained stable after 6 months of water storage (p > 0.05).
  
  
  CONCLUSIONS
  Pretreatment with EGCG preserved the bond of Adper Single Bond 2 to dentin after six months of storage equally well as pretreatment with chlorhexidine digluconate.
authors.forename: Sérgio Lima
authors.initials: SL
authors.lastname: Santiago
authors.forename: Raquel
authors.initials: R
authors.lastname: Osorio
authors.forename: Jiovanne Rabelo
authors.initials: JR
authors.lastname: Neri
authors.forename: Ricardo Marins
authors.initials: RM
authors.lastname: Carvalho
authors.forename: Manuel
authors.initials: M
authors.lastname: Toledano
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000268:Adhesiveness; D000975:Antioxidants / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D006801:Humans; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D011480:Protease Inhibitors / Q000737:chemistry*; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C554641:Adper single bond 2; D000975:Antioxidants; D003188:Composite Resins; D003738:Dental Cements; C444701:Filtek Z250; D010756:Phosphoric Acids; D011480:Protease Inhibitors; D014867:Water; D002392:Catechin; C045651:epigallocatechin gallate; C030242:phosphoric acid; C010882:chlorhexidine gluconate; D002710:Chlorhexidine