This study evaluates two mechanical properties, tensile strength and tear strength, of maxillofacial materials reinforced with functional polyhedral silsesquioxane (POSS) nanoparticles at 0.0, 0.5, 1.0, 2.0, and 5.0% (mass/mass) loading. Adding POSS was found to significantly affect the overall tensile strength and extensibility of the maxillofacial material. Significant differences were found in mean peak load (p =.050) and extension before failure (p =.050), respectively, between concentrations of 0% and 5%. For tear resistance, a significant difference was observed inmean load (p =.002) between concentrations of 1% and 5%. Significant differences were also observed in extension before failure between concentrations of 0% and 1% (p =.002) and between 0% and 2% (p =.002). Increased resistance to tensile or shearing stresses could lead to greater clinical longevity. The following results suggest that functional nanoparticles can be used to improve properties without compromising clinical handling.