Preparation and characterization of silica based nanoclusters as reinforcement for dental applications

As composite resins become the most extensively utilized material in the field of cosmetic and restorative dentistry, several strategies to overcome dental composites' challenges such as long‐term mechanical failure and secondary caries are continuously being developed. Among them, the design of suitable fillers to optimize their clinical performance has been given priority in addressing those shortcomings. In this study, silica‐based nanoclusters were synthesized and used as fillers to prepare UV curable dental composites was assessed. Nanoclusters were prepared by prepolymerization followed by pulverization and sieving of commercial silica nanoparticles with triethylene glycol dimethacrylate monomer. The composites were then made by filling 55:25:20 weight ratio of urethane dimethacrylate, bisphenol A glycidyl methacrylate, and triethylene glycol dimethacrylate, respectively with varying concentration of nanoclusters. The clusters and composites were characterized by SEM, TGA, and FTIR analyzes. The results have shown a significant improvement of physical and mechanical properties in composites containing nanoclusters. Increasing nanocluster concentration caused a reduction in composite polymerization shrinkage, water absorption and solubility as well as limited rise of flexural strength. At 50% filler load, nanoclusters doped composites exhibited higher flexural strength than nanoparticles doped composites. Furthermore, the blending of nanoclusters with nanoparticles as fillers produced the composites having the lowest polymerization shrinkage (2.2%) and the highest flexural strength (113.91 MPa). Overall, the synthesized nanoclusters have shown greater performance in comparison with the current available silica nanoparticles. Schematic diagram for experimental studies