Bond strength of a self-adhesive cement to deproteinized dentin: effect of NaOCl concentration and application time

• Published in: Revista odonto ciência 2012-10, Vol.27 (4)
• Main Authors: Luis Faria-e-Silva, André, Wesley da Graça Nunes, Flávio, Augusto Melo de Mendonça, Adriano, Vieira dos Santos, Silvando, Griza, Sandro
• Format: Article
• Language: English
• ISSN: 0102-9460; 1980-6523

Purpose: This study investigated the effect of different protocols of deproteinization on the bond strength of a self-adhesive cement to dentin. Methods: Buccal surfaces of bovine incisors were abraded to expose a flat dentin. After acid-etching and rinsing, the dentin was deproteinized using 5 or 20% NaOCl for 2 or 10 min. The absence of treatment and acid-etching only were used as controls. Cylinders were build-up with the self-adhesive resin cement RelyX Unicem and submitted to shear load. Data were evaluated by one-way and two-way (excluding the controls) ANOVA and Tukey's test (?=0.05). Failure modes were classified under magnification. Results: Only the deproteinization with 5% NaOCl for 10 min improved the bond strength compared to the absence of treatment. Except for 20% NaOCl for 10 min, all protocols of deproteinization resulted in higher bond strength than those obtained to etched dentin. Independently of application time, deproteinization with 5% NaOCl promoted higher bond strength than 20% NaOCl. It was observed a predominance of adhesive failures. Conclusions: Both concentration and application time of NaOCl intervenes on bond strength of self-adhesive resin cement to deproteinized dentin.