Comparative Evaluation of the Effects of Yttrium Stabilized Zirconia Nanoparticles (YSZrO2- NP) and Porcelain Particles on Property Enhancement of Polymethylmethacrylate (PMMA) Denture Composites

The durability and strength of acrylic dentures are crucial for patient satisfaction and oral health. However, denture failure rates remain a significant concern. Reinforcing acrylic dentures with nanoparticles such as zirconia improves the mechanical properties of PMMA dentures. This study examines the enhancement of mechanical and physical properties of heat-cured PMMA dentures reinforced with varying amounts (1, 3, 5, 7, and 9 wt.%) of YSZrO 2 -NP and porcelain particles. The components were fabricated with standard dimensions in a dental flask, compacted using a hydraulic press, and polymerized for 120 minutes in a thermos-stated water curing bath. The properties analyzed included flexural strength, hardness, wear resistance, microstructure, and biocompatibility. The Flexural strength increased significantly with YSZrO 2 -NP reinforcement (315% at 7 wt.%), whereas porcelain particles reinforcement showed a minimal increase (40% at 9 wt.%). Hardness slightly decreased for all YSZrO 2 -NP/PMMA compositions (51% at 9 wt.%), while porcelain reinforcement showed a slight increase across all amounts, reaching up to 11% at 9 wt.%. Wear resistance improved with all filler additions in the PMMA. SEM analysis revealed uniformly dispersed particles in the PMMA matrix for 1-5 wt. % porcelain particles and ZrO 2 NP composites. In contrast, 7-9 wt. % reinforcement showed non-uniform dispersion. Reinforcing PMMA with YSZrO 2 -NP and porcelain particles enhanced its mechanical and physical properties. Therefore, micro- and nanoparticles of ceramics are a viable option for improving the strength and rigidity of PMMA dentures.