Experimental Evaluation of a Universal Adhesive Modified With Fluorinated Graphene Nanoparticles: An In Vitro Study

Background Recent developments in nanotechnology have made it possible to add nanoparticles to dental materials, leading to improved physical and biological characteristics. The use of fluorinated graphene nanoparticles (FGNPs) has attracted attention due to their high surface area, chemical stability, and potential bioactive effects, which can improve adhesion and reduce problems related to bonding. Aim To evaluate and compare the chemical and interfacial effects of incorporating fluoride graphene nanoparticles into a universal adhesive system using Fourier-transform infrared spectroscopy (FTIR) and confocal laser scanning microscopy (CLSM) analysis. Materials and methods Thirty-two human extracted mandibular molars were randomized into two groups (16 for each group). The two groups were treated with 37% phosphoric acid on dentin and then a conventional universal adhesive or a modified universal adhesive with 2% FGNPs was applied. For FTIR and CLSM evaluation, the samples were further subdivided into groups (n = 8). Independent-sample t-test was used to analyze the data at a significance level of p<0.05. Results Analysis with FTIR showed characteristic C-F peaks with reduced O-H intensity in modified adhesive with FGNPs. The hybrid layer thickness and resin tag length was significantly greater in the modified adhesive group compared with the unmodified adhesive group with P=0.0001 and 0.0003 respectively. Conclusion The incorporation of FGNPs in universal adhesive has improved the chemical bonding and micromechanical interlocking, with enhanced hybrid layer thickness at dentin adhesive interface.