title: Effect of antioxidants on the dentin interface bond stability of adhesives exposed to hydrolytic degradation.
abstract: OBJECTIVE
  This study assessed the effect of antioxidants vitamin C (Vit. C), vitamin E (Vit. E) and quercetin (Querc) on the dentin bonding performance, degree of conversion, and rate of polymerization of three commercial adhesive systems (Adper Single Bond 2 [SB], Clearfil SE Bond [CSE], Adper Easy Bond [EB]).
  
  
  METHODS
  Human premolars were restored using antioxidant-doped adhesives. The samples were stored for 24 h in distilled water or 6 months under simulated pulpal pressure. Teeth were cut into sticks and the microtensile bond strength (μTBS) to dentin was tested in a universal testing machine. Qualitative nanoleakage analysis was performed from a central stick of each restored tooth. Degree of conversion and rate of polymerization of adhesive systems were evaluated in triplicate using real-time FT-IR.
  
  
  RESULTS
  Although the inclusion of the antioxidants negatively affected the μTBS over 24 h, the antioxidant-doped adhesives maintained (SB-Vit. C, SB-Vit. E, CSE-Vit. C, EB-Querc) or increased (SB-Querc, CSE-Vit. E, CSE-Querc, EB-Vit. E, and EB-Vit. C) their μTBS during 6 months of storage. Only the μTBS of Adper Single Bond 2 dropped significantly after 6 months among the control groups. Slight changes in the nanoleakage pattern after aging were observed in all groups, except for the EB-control group, which showed a noteworthy increase in nanoleakage after 6 months, and for EB-Vit. C, which presented a remarkable decrease. A lower degree of conversion was obtained with all antioxidants in SB and EB, except for the EB-Vit. E group. Similar degrees of conversion were attained in control and experimental groups for CSE. The rate of polymerization was reduced in antioxidant-doped adhesives.
  
  
  CONCLUSIONS
  The performance of antioxidants changed according to the adhesive system to which they were added, and antioxidant-doped adhesives appear to have a positive effect on the adhesive interface durability, since their bond strength obtained after 24 h was maintained or increased over time.
authors.forename: Valéria B
authors.initials: VB
authors.lastname: Gotti
authors.forename: Victor P
authors.initials: VP
authors.lastname: Feitosa
authors.forename: Salvatore
authors.initials: S
authors.lastname: Sauro
authors.forename: Lourenço
authors.initials: L
authors.lastname: Correr-Sobrinho
authors.forename: Fernanda B
authors.initials: FB
authors.lastname: Leal
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Stansbury
authors.forename: Américo B
authors.initials: AB
authors.lastname: Correr
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003763:Dental Leakage / Q000145:classification; D003799:Dental Stress Analysis / Q000295:instrumentation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006868:Hydrolysis; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D058105:Polymerization; D011794:Quercetin / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013718:Tensile Strength; D013997:Time Factors; D014810:Vitamin E / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: C554641:Adper single bond 2; D000975:Antioxidants; C438313:Clearfil SE Bond; D003188:Composite Resins; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D019279:Resin Cements; C584661:easy bond; C533204:filtek Z350; D014867:Water; D014810:Vitamin E; D011794:Quercetin; D001205:Ascorbic Acid