title: Effect of sodium ascorbate on resin bonding to sodium perborate-bleached dentin.
abstract: SUMMARY This was an in vitro study to evaluate the effect of sodium ascorbate on the microshear bond strength (MSBS) of resin composite to sodium perborate-bleached dentin. Molar dentin sections were divided into six groups: 1) control, 2) sodium perborate (SP) bleach and immediate bonding, 3) SP and 30 second sodium ascorbate (SA); 4) SP and 1 minute SA; 5) SP and 2 minute SA; and 6) SP and 7 day delay before bonding. They were further divided into two-step self-etching (Clearfil SE Bond) or all-in-one self-etching (Xeno IV) adhesive systems. Resin composite microtubes were bonded according to dentin location-center, pulp horn, and peripheral positions-and an MSBS test was carried out. Failure mode was determined using light microscopy and scanning electron microscopy. There were no significant differences between the treatment types/groups. MSBSs were significantly higher for two-step self-etching adhesive compared with all-in-one self-etching adhesive (p=0.028). For the all-in-one adhesive, MSBSs at the center and pulp horn positions were significantly lower than the peripheral positions (p<0.001). All-in-one groups had significantly more adhesive failures than two-step adhesive groups (p=0.015). The odds of adhesive failure were higher at the pulp horn position than the peripheral position (p=0.004). Sodium perborate bleaching of dentin had no effect on MSBS or mode of failure for either two-step or all-in-one self-etching adhesives; therefore, the effect of sodium ascorbate was negligible. The two-step adhesive groups demonstrated the highest MSBS, and the all-in-one groups, when bonded to center and pulp horn dentin, exhibited the lowest MSBS.
authors.forename: M
authors.initials: M
authors.lastname: Yoon
authors.forename: M F
authors.initials: MF
authors.lastname: Burrow
authors.forename: R
authors.initials: R
authors.lastname: Wong
authors.forename: P
authors.initials: P
authors.lastname: Parashos
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology*; D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000627:therapeutic use*; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000627:therapeutic use*; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D006801:Humans; D066298:In Vitro Techniques; D014073:Tooth Bleaching / Q000009:adverse effects*; D058205:Tooth Bleaching Agents / Q000494:pharmacology*
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D058205:Tooth Bleaching Agents; D001205:Ascorbic Acid