Available online 29 March 2023

To evaluate the benefits of a novel dentin-bonding primer, namely, isocyanate-terminated urethane methacrylate precursor (UMP), which can form covalent bonds with demineralized dentin collagen.

The synthesized and purified UMP monomer was characterized and tested its effects on the degree of conversion (DC) and wettability of an acetone-based dental adhesive. Then UMP primers of different concentrations were formulated and used to prepare adhesive specimens, which were compared with solvent-treated groups. Primer-treated specimens with and without aging were also compared. To evaluate the bonding interface, microtensile strength tests, nano-indentation tests and nanoleakage- eavaluation were performed using a field-emission scanning electron microscope and nano-indenter. Data were analyzed using SPSS 20.0 software with significance set at α = 0.05 using one-way analysis of variance (ANOVA) and two-way ANOVA to characterize the effects of the primer.

Treatment with the UMP primer promoted the DC and wettability of the adhesive on the demineralized dentin surface (P < 0.05); it also increased the bond strength of the aged dentin bonding interface (P < 0.05). Nanoleakage was reduced; the bonding interface became more stable, and the continuity and strength of the hybrid layer improved (P < 0.05) following UMP treatment. The application of 5 mM UMP as a primer for dentin bonding could lead to a stable bonding interface and long-lasting bonding effects.

The use of 5 mM UMP primer developed in this study could improve dentin bonding durability and has excellent clinical application prospects.

Adhesive

Dentin

Hybrid layer

Isocyanate

Durability

© 2023 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.