The effect of prime-and-rinse approach using MDP micellar solutions on extrafibrillar demineralization and dentin bond performance.

Abstract Objective This study investigated the effects of prime-and-rinse approach using 10-methacryloyloxydecyl dihydrogen phosphate (MDP) micellar solutions on extrafibrillar demineralization and dentin bond performance of etch-and-rinse adhesive. Methods The micellar solutions were prepared by adding 15% MDP in two ethanol-aqueous (75:25, 55:45 V/V%) solutions, referring to MDP/EtOH75 and MDP/EtOH55. After mid-coronal dentin surfaces were either etched (control) or conditioned with MDP/EtOH75 and MDP/EtOH55 and rinsed, they were applied with adhesive (Adpter Single Bond 2) in dry- or wet-bonding mode and placed with composite resin (Filtek Z350 XT). They were prepared into multiple micro-beams for micro-tensile bond strengths (MTBS) testing after storage in water for 24 h or subjecting to thermocycling. The other pretreated dentin surfaces were analyzed by TF-XRD, ATR-FTIR, HRTEM, FE-SEM, contact angle measurement and nanoindentation testing. The MTBS data was analyzed with two-way ANOVA followed by LSD post-hoc test. Results MDP/EtOH75 produced significantly greater MTBS values than MDP/EtOH55 and control after thermocycling aging in dry- or wet-bonding mode (P Significance Prime-and-rinse approach using MDP/EtOH75 micellar solution could produce mostly extrafibrillar demineralization, and greatly increase dentin bond durability in dry- or wet-bonding mode.