Nanoclay-reinforced polymethylmethacrylate and its mechanical properties

BACKGROUND: Incorporation of extra fillers into dental resins might enhance their physical properties. In this study, the tensile and impact strengths of modified heat-curing acrylic resin reinforced with nanoclay were investigated. MATERIALS AND METHODS: In this experimental study, nanoclay-acrylic resin composite was prepared by mixing 0.5, 1, and 2 wt% of nanoclay with methacrylate monomer in an ultrasonic probe, followed by mixing with the polymethylmethacrylate (PMMA) powder. 24 cubic 20 mm × 20 mm × 200-mm specimens for each test, 18 samples containing nanoclay and 6 samples for the control group and a total of 48 samples were prepared. The tensile and impact strengths of the samples were tested according to ISO 527 and 179, respectively. One-way ANOVA was used for statistical analysis, followed by multiple comparison tests (Scheffé's test). Statistical significance was set at P < 0.05. RESULTS: The maximum mean tensile and impact strengths were recorded in the control group, and an acrylic resin containing 2% of nanoclay demonstrated the minimum mean in all the tests. Increasing the percentage of nanoclay in PMMA compromised the tensile strength (P < 0.05) with no effect on its impact strength. CONCLUSION: Incorporation of nanoclay particles into acrylic resins can adversely affect the mechanical properties of the final products, and this effect is directly correlated with the concentration of nanoparticles.