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BIBTEX RIS

Reversal of Compromised Bonding to Oxidized Etched Dentin

2001; SAGE Publishing; Volume: 80; Issue: 10 Linguagem: Inglês

10.1177/00220345010800101101

1544-0591

S.C.N. Lai, Y.F. Mak, Gary S.P. Cheung, Raquel Osorio, Manuel Toledano, R.M. Carvalho, Franklin R. Tay, D.H. Pashley,

Endodontics and Root Canal Treatments

The mechanism responsible for hydrogenperoxide- or sodium-hypochlorite-induced reductions in dentin bond strength is unknown. This in vitro study tested the hypothesis that these oxidizing agents were responsible by attempting to reverse the effect with sodium ascorbate, a reducing agent. Human dentin was treated with these oxidants before or after being acid-etched and with or without post-treatment with sodium ascorbate. They were bonded with either Single Bond or Excite. Hydrogen peroxide reduced the bond strengths of both adhesives, while sodium hypochlorite produced reduction in adhesion of only Single Bond (p < 0.05). Following treatment with sodium ascorbate, reductions in bond strength were reversed. Transmission and scanning electron microscopy showed partial removal of the demineralized collagen matrix only by sodium hypochlorite. The observed compromised bond strengths cannot be attributed to incomplete deproteinization and may be related to changes in the redox potential of the bonding substrates.