Effect of flavonoid-based experimental primers on dentin microtensile bond strength and interface morphology

Abstract

ObjectivesThis study evaluated the effect of four flavonoid-based experimental primers on the dentin bond strength (μTBS) and the bonding interface morphology of an adhesive. Materials and methodsFour experimental primer solutions containing two different flavonoids (Kaempferol and Naringin) in two concentrations (10 mM and 20 mM) were applied for 30 s or 60 s on dentin after phosphoric acid etching, followed by an etch-and-rinse adhesive system. A Negative Control (NC) consisting of dentin not treated with experimental primer solutions and Positive Controls (PC) that used 0.2% chlorhexidine solution for 30 and 60 s were also tested. Eighty-eight teeth were selected for dentin μTBS (n = 8). Dentin-adhesive interface morphology (n = 4) were analyzed by confocal laser scanning microscopy (CLSM). Data were analyzed by mixed three-way ANOVA (μTBS) and two-way ANOVA (CLSM) (α = 0.05). Dentin μTBS was analyzed at 24 h and one-year, while the bonding interface morphology was evaluated at 24 h. ResultsRegarding μTBS, no statistical difference was found between the experimental groups and NC at 24 h. However, most experimental primers applied for 60 s presented higher values compared to NC at one-year. Hybrid layer formation and adhesive infiltration was observed in all groups by CLSM. ConclusionsThe application of flavonoid-based experimental primers for 60 s was able to produce higher μTBS than those obtained with NC and PC after one-year of artificial aging, without interfering with interface morphology.