Pilot study of conditioner/primer effects on resin-dentin bonding after provisional cement contamination using SEM, energy dispersive x-ray spectroscopy, and bond strength evaluation measures

Statement of problem. Previous studies have shown that provisional cement c annot be completely removed from the dentin surface and the remnants inhibi t adhesion of resin cement to dentin. Purpose. This study investigated the effects of dentin conditioners on resi n-dentin bonding after provisional cement contamination. Material and methods. A total of 216 bovine dentin specimens were divided i nto 2 groups with and without provisional cement coating on the dentin surf ace. Each group was further divided into 3 subgroups with 2 conditioning me thods and without dentin conditioning (36 specimens per subgroup). The 2 me thods applied were (1) phosphoric acid etching and (2) phosphoric acid etch ing, followed sodium hypochlorite gel. Provisional cement was completely re moved with 3 current before dentin conditioning. Stainless steel rods were luted to dentin surfaces with Panavia 21 resin cement. Tensile bond strengt hs were measured before and after thermocycling. The dentin surface was ana lyzed SEM and energy dispersive x-ray spectroscopy. Three-way ANOVA and Sch effe's comparison test were performed (P = .05). Results. Bond strength was significantly influenced by provisional cement a pplication, type of dentin conditioning, and thermocycling. Bond strength d ecreased when treated with provisional cement, but the decreased strengths were restored to their original values or higher by both dentin conditioner s used. Specimens treated with sodium hypochlorite gel applied after phosph oric acid etching demonstrated the highest bond strengths with good stabili ty after thermocycling. Conclusion. Application of sodium hypochlorite gel after phosphoric acid et ching was more effective than etching with phosphoric acid alone to elimina te the inhibitory effect of provisional cement remnants on adhesion between resin cement and dentin.