Effect of Dentin- Pretreatment using Arginine, Polyamidoamine Dendrimer and their Combination on Bond Durability and Micromorphology.

Objectives To analyze the impact of dentin pretreatment using arginine (L.arg), amineterminated polyamidoamine dendrimer (PAMAM-NH2), and their combination on microtensile bond strength (muTBS) and resin-dentin micromorphology. Methods Demineralized middle-coronal dentin surfaces of eighty sound molars were randomly distributed among four groups depending on the implemented surface pretreatment (n=20): (1) 8% L.arg, (2) PAMAM, (3) PAMAM + L.arg, and (4) untreated dentin (control group). Following bonding and composite build-up procedures, each group was subdivided into; the non-aged subgroup, where the muTBS was measured immediately, and the aged subgroup, where the specimens were thermo-cycled before muTBS. Resin-dentin sticks were prepared for muTBS testing. The failure mode distribution was analyzed. The resin-dentin interface was investigated using Field-emission scanning electron microscopy. A two-way ANOVA was utilized, followed by Tukey's post hoc test. Results before thermo-cycling, group 1 had the highest muTBS mean value followed by groups 2 and 4 without a significant difference. While group 3 showed the statistically least muTBS (P <0.001). After thermo-cycling, PAMAM pretreatment significantly increased the muTBS Conclusions PAMAM pretreatment possessed a favorable impact on the dentin- resin bonding durability. Clinical relevance PAMAM -NH2 and L.arg surface treatment could improve immediate and long-term stability of the dentin-resin bonding.