Concentration-Dependent Reinforcement of Self-Curing Poly(methyl methacrylate) with Polyetheretherketone: Mechanical Performance and Physicochemical Stability

Self-curing poly(methyl methacrylate) (PMMA) remains widely used for provisional restorations and denture bases; however, its limited mechanical strength and susceptibility to water-related degradation restrict long-term performance. This study investigated the concentration-dependent reinforcement of self-curing PMMA with polyetheretherketone (PEEK) particles and evaluated mechanical properties and physicochemical stability. PMMA specimens containing different PEEK concentrations were fabricated and tested for flexural strength, compressive strength, surface hardness, water sorption, and water solubility according to standardized protocols. Mechanical performance demonstrated a concentration-dependent enhancement, with moderate PEEK incorporation significantly improving strength parameters compared to the control group. Excessive filler loading, however, did not yield proportional improvements. Water sorption and solubility values remained within clinically acceptable and ISO-recommended limits. These findings suggest that controlled PEEK reinforcement provides a feasible approach to enhancing the mechanical durability of self-curing PMMA without compromising physicochemical stability. The study offers a practical material modification strategy for improving interim prosthetic materials in clinical dentistry.