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Aim:The fracture of the denture resulting from the accidental fall on the ground is affected by the impact strength of the acrylic resin. Many attempts have been made to improve the mechanical properties of acrylic resin by reinforcing it with different materials. The aim of this study was to evaluate the effect of addition of different nano materials on the impact strength and surface hardness of the acrylic resin. Materials and methods: Fifty samples of dimensions 65 mm × 10 mm × 3 mm were made and divided into five groups. Group I is the control group of heat-activated polymethyl methacrylate (PMMA) acrylic resin, while groups II, III, IV, and V are having 1% and 3% zirconium oxide (ZrO 2 ) and silicon dioxide (SiO 2 ) nanoparticles in heat-activated PMMA by weight, respectively. A metallic block was fabricated and invested into addition silicone impression material to form a mold. The modeling wax was melted and flown into the mold cavity to form the wax block. The samples were subsequently polymerized, retrieved, finished, and polished. Impact strength and surface hardness were measured by Izod impact testing machine and Vickers hardness tester, respectively. Results: The results showed that the control group had the highest impact strength and lowest value was observed with 1% SiO 2 . The value of Vickers hardness was maximum with 1% ZrO 2 and least with the control group. The analysis of variance (ANOVA) for both the impact strength and surface hardness indicated a p value of <0.001, which is very highly significant. Conclusion: Incorporation of ZrO 2 and SiO 2 nanoparticles into the heat-activated PMMA affects the impact strength and surface hardness.

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Residual ridge resorption is a chronic, progressive, irreversible and cumulative disease. Stability is defined as resistance to horizontal displacement of prosthesis. Providing a stable lower denture has been challenging for dentists. This article outlines the management of the mandibular ridge resorption with dynamic impression technique. Stability of complete lower dentures has challenged dentists and patients alike. Dynamic impression technique is clinically significant for management of resorbed mandibular ridge, as the range of action of the muscles and other structures that relate to the denture space is recorded by an impression so that the denture can be shaped accordingly.