Preparation Of Dental Restoration Composites With Improved Interfacial Adhesion Basing On Mussel-Inspired Surface Modification And Pmma Coating

Prepregs are used as adaptable fiber posts for clinical therapy of damaged teeth via endodontical treatment, especially for those curved canals. Prepreg is a kind of pre-impregnated composite fibers with resin. The lack of good interfacial adhesion between the fibers and the polymeric matrix usually gives rise to inferior performance. Surface treatments are common to obtain strong retention between different constituents. In this study, a mussel-inspired modifier, i.e. dopamine, was used to treat the surface of glass fibers, and thus improve the interfacial adhesion between glass fibers and light-curable Bis-GMA/TEGDMA resin for dental applications. Polydopamine could be easily mounted onto glass fibers by oxidative polymerization in aqueous solution, which has shown excellent adhesion to various kinds of substrates including non-wetting polytetrafluoroethylene. Several modified glass fibers were prepared by coating polydopamine, polymethylmethacrylate (PMMA) or both of them. Using the pristine glass fibers as reference, fiber reinforced Bis-GMA/TEGDMA composites were obtained by incorporating the modified glass fibers. With characterizations of "three-point" bending test, dynamic mechanical thermal analysis (DMTA) and pull-out test, the results demonstrated that all the surface treated fibers had good interfacial adhesion to the resin in comparion to the pristine fibers. In particular, the fibers co-coated with polydopamine and PMMA achieved the highest interfacial adhesion strength. It wa suggested contributing to the compatibility between PMMA and Bis-GMA/TEGDMA, as well as the strong adhesion ability of polydopamine to both glass fibers and PMMA coating.In the second part of this study, silica nanoparticles were synthesized using Stober’s method, followed by polydopamine coating. The polydopamine-modified silica nanoparticles were then attached onto the polydopamine-modified glass fibers. Accordingly, the fibers were applied as a kind of multi-scale/multi-dimensional reinforcement for Bis-GMA/TEGDMA. Benefit from the "anchoring effect" of silica nanoparticls, the resulting composites displayed better interfacial adhesion between fibers and resin matrix, in comparison with polydopamine-modified glass fibers.In a summary, the present study had raised a universal surface modification approach to improve interfacial adhesion between different constituents, which has wide application in developing organic-inorganic composite materials.