title: Effects of time and concentration of sodium ascorbate on reversal of NaOCl-induced reduction in bond strengths.
abstract: The use of NaOCl as an endodontic irrigant lowers the bond strength of resin cements but this can be reversed by the use of 10% sodium ascorbate for 10 min. The objective of this study was to evaluate the effect of time and concentration of ascorbate at restoring the bond strength. Group 1 roots were prepared using 0.9% NaCl as an irrigant; group 2 roots were irrigated with 5.25% NaOCl; group 3 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 10 min; group 4 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 3 min; group 5 roots were irrigated with 5.25% NaOCl followed by 10% ascorbate for 1 min; and group 6 roots were irrigated with 5.25% NaOCl followed by 20% ascorbate for 1 min. All roots were then filled with C&B Metabond, stored 1 day in water, and then cross-sectioned into 6 slabs, 1 mm thick, that were trimmed and tested for tensile bond strength. The results demonstrated that 5.25% NaOCl irrigation produced (p < 0.05) significant reduction in resin-dentin bond strengths, but this can be reversed by 10% ascorbate treatment for 1 min.
authors.affiliation: Department of Endodontics, School of Dentistry, University of Alabama, Birmingham, Alabama, USA.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Weston
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ito
authors.forename: Bakul
authors.initials: B
authors.lastname: Wadgaonkar
authors.forename: David H
authors.initials: DH
authors.lastname: Pashley
mesh_terms: D000704:Analysis of Variance; D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D001840:Dental Bonding; D006801:Humans; D012388:Root Canal Irrigants / Q000009:adverse effects*; D012973:Sodium Hypochlorite / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D013718:Tensile Strength / Q000187:drug effects; D013997:Time Factors