Zinc oxide quantum dot–coated mesoporous silica as hybrid fillers for high-performance dental composites: characterization and mechanical optimization

Zinc oxide quantum dots (ZnO QDs) were incorporated into a dental composite using mesoporous silica framework. The present work focuses on evaluating their effects on the composite’s mechanical and physical properties. ZnO QDs were synthesized via a precipitation method and subsequently functionalized with 3-(Methacryloxy) propyltrimethoxysilane (3-MPS). Similarly, mesoporous silica (Santa Barbara Amorphous-15, SBA-15) was functionalized with 3-MPS and used to stabilize ZnO QDs, forming SBA-15@ZnO QDs hybrid fillers. Comprehensive characterization of the hybrid fillers was conducted using a range of analytical techniques. These fillers were then incorporated into model resin-based dental composites at varying weight percentages, and their key mechanical properties were systematically evaluated. One-way ANOVA analysis was conducted for statistical analysis between different groups. A grid search optimization was conducted to determine the optimal filler loading based on mechanical performance. A substantial improvement (35%) in compressive strength was observed at 11 wt% compared to the control group, while the compressive modulus remained statistically unchanged. Although flexural strength and modulus of elasticity were significantly reduced, the composite still demonstrated clinically acceptable flexural performance. Based on a grid search optimization approach, 11 wt% SBA-15@ZnO QDs were identified as the optimal filler loading, achieving the highest compressive strength while maintaining acceptable flexural properties. This study demonstrates the potential of mesoporous silica microparticles as an effective inorganic framework for the incorporation of ZnO QDs into the dental resin matrix, enabling high filler loadings of up to 11 wt% without compromising mechanical performance.