Influence of magnesium oxide nanoparticles on in vitro mechanical and antibacterial performance of self-curing dental polymethyl-methacrylate.

Self-curing polymethyl methacrylate is widely used for provisional restorations, retainers and denture repairs, but its lack of antibacterial activity favors bacterial colonization. Magnesium oxide nanoparticles exhibit broad antibacterial effects through the generation of reactive oxygen species. This study evaluated the influence of mechanochemically synthesized magnesium oxide nanoparticles on the mechanical properties of self-curing polymethyl methacrylate and on its antibacterial activity against Actinomyces israelii, Porphyromonas gingivalis, Capnocytophaga gingivalis, Prevotella intermedia, Streptococcus sanguinis, Streptococcus sobrinus, Eikenella corrodens and Fusobacterium nucleatum sensu stricto. Nanoparticles (1, 3 and 5 wt%) were incorporated into the polymer powder and polymerized. Flexural strength, elastic modulus, water sorption and solubility were determined. Antibacterial activity was assessed in broth cultures and quantified by optical density at 595 nm, with viability confirmed on agar. Nanoparticle incorporation provided in vitro antibacterial activity while partially reducing mechanical strength. These results suggest a targeted use of modified polymethyl methacrylate for applications prioritizing.