Effects of sodium hypochlorite and RC-Prep on bond strengths of resin cement to endodontic surfaces

There is concern that the use of sodium hypochlorite (NaOCl) and RC-Prep ma y lower the bond strength of resin cements. The objective of this study was to evaluate the effect of 5% NaOCl and RC-Prep treatment on the bond stren gth of a resin cement, C&B Metabond. Control roots (group 1) were biomechan ically prepared using 0.9% NaCl as an irrigant; group 2, roots with 5% NaOC l; group 3, roots with RC-Prep; group 4, roots with 0.9% NaCl followed by 1 0% ascorbic acid; group 5, roots with 5% NaOCl followed by 10% ascorbic aci d (pH 4); group 6, roots with 5% NaOCl followed by 10% neutral sodium ascor bate; and group 7, roots with RC-Prep followed by 10% ascorbic acid. All ro ots were then filled with C&B Metabond, incubated in water for 24 h, and th en cross-sectioned into six 1-mm thick slabs representing cervical and midd le root dentin. The slabs were trimmed and tested for tensile bond strength . The results demonstrated that both 5% NaOCl and RC-Prep produced signific antly (p < 0.05) large reductions in resin-dentin bond strengths, and the r eductions could be completely reversed by the application of either 10% asc orbic acid or 10% sodium ascorbate.