Effect of dentin pre-treatment with a casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste on dentin bond strength in tridimensional cavities

Objective. This study aimed to evaluate the push-out bond strength of dimethacrylate (Clearfil SE Bond/Filtek Z250; and Adper SE Plus/Filtek Z250) and silorane-based (Filtek P90 adhesive system/Filtek P90 composite resin) restorative systems following selective dentin pre-treatment with a CPP-ACP-containing paste (MI Paste). Materials and methods. Sixty bovine incisors were utilized. The buccal surface was wet-ground to obtain a flat dentin area. Standardized conical cavities were then prepared. Adhesive systems were applied according to manufacturers' directions and the composites were bulk-inserted into the cavity. The push-out bond strength test was performed at a universal testing machine (0.5 mm/min) until failure; failure modes were analyzed by scanning electron microscopy. Data were analyzed by two-way ANOVA and Tukey post-hoc test (p < 0.05). Results. For Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin, the dentin pre-treatment did not influence bond strength means. For Adper SE Plus/Filtek Z250, dentin samples treated with MI Paste had statistically higher bond strength means than non-treated specimens. Adhesive failures were more frequent. Conclusion. Dentin pre-treatment with the CPP-ACP containing paste did not negatively affect bond strength for Clearfil SE Bond/Filtek Z250 and Filtek P90 adhesive system/Filtek P90 composite resin restorative systems and improved bond strength for the Adper SE Plus/Filtek Z250 restorative system.71127127