Effect of Nanoparticles on the Mechanical Properties of Polymethyl Methacrylate Denture Base Material

Polymethylmethacrylate (PMMA) has been widely used as a denture base material due to its favorable properties but exhibits limitations in mechanical strength. This study investigated the effects of incorporating three different nanoparticles - zirconium dioxide (ZrO₂), silicon dioxide (SiO₂), and diamond nanoparticles (DNPs) at varying concentrations (0.5%, 1.0%, 2.5%, and 5.0%) on the mechanical properties of PMMA denture base material. The incorporation of nanoparticles demonstrated concentration-dependent effects on PMMA properties. ZrO₂ nanoparticles at 1.0% concentration showed optimal results with improved hardness (21.4 ± 0.8 VHN) while maintaining acceptable surface roughness. Higher concentrations (2.5% and 5.0%) led to increased surface roughness and decreased hardness across all nanoparticle types. Diamond nanoparticles exhibited the highest surface roughness (0.146 ± 0.017 μm) at 5.0% concentration, while SiO₂ showed moderate improvements in mechanical properties at lower concentrations. Surface morphology analysis revealed excellent particle dispersion at 0.5-1.0% concentrations, with significant agglomeration observed at higher concentrations. The study determines that 1.0% concentration is the optimum level to utilize for the addition of nanoparticles into PMMA denture base materials, wherein ZrO₂ nanoparticles show the optimum balance of enhanced material properties and preserved surface features. The findings show that precise control of particle concentration is required to achieve enhanced material properties without compromising surface integrity that will in turn translate to enhanced clinical performance of dental prostheses.