Physicomechanical and Antibacterial Properties of Resin-Based Dental Sealants Modified with Graphene Oxide Nanoparticles

This study evaluated the influence of incorporating graphene oxide (GO) nanoparticles (0.1, 0.25, and 0.5 wt%) into resin-based pit and fissure sealants on their mechanical, physical, antibacterial, and cytocompatible properties, compared with a commercial reference material. Experimental sealants containing GO (G2–G4) were prepared, with an unmodified resin as control (G1) and Helioseal F Plus as commercial comparison (G5). GO morphology was characterized by TEM. Specimens (n = 240) were tested for Vickers microhardness, viscosity, surface roughness change (ΔRa) after simulated toothbrushing, and fluorescence (% blue channel). Antibacterial activity against Streptococcus mutans was assessed using a direct contact test (ASTM E2180), and antibacterial rate (AR) was calculated. Cytotoxicity was evaluated via MTT assay with human gingival fibroblasts following ISO 10993-5. Data were analyzed using one-way ANOVA and Tukey's post hoc test (α = 0.05). GO incorporation significantly increased microhardness, with G4 (0.5 wt% GO) showing the highest VHN (p < 0.05). Viscosity rose modestly with GO content, while the commercial sealant exhibited the highest value. G3 (0.25 wt% GO) displayed the lowest ΔRa after brushing. All GO groups showed higher fluorescence than the control (p < 0.05). Antibacterial activity increased with GO concentration (AR = 83.84–88.88%), though G5 achieved the highest AR (99.42%). All formulations maintained > 70% cell viability, confirming acceptable biocompatibility. Low-level GO reinforcement enhanced surface hardness, wear resistance, fluorescence, and antibacterial performance of resin-based sealants without compromising cytocompatibility. GO represents a promising multifunctional nanofiller for next-generation sealants aimed at improving durability and caries prevention.