Tensile strength and impact strength of color modified acrylic resin reinforced with titanium dioxide nanoparticles

BACKGROUND: Poor mechanical properties are among the main limitations of acrylic resins. Addition of titanium dioxide (TiO2) nanoparticles to acrylic resin has been shown to improve its mechanical properties with an adverse effect on its color. Thus, this study sought to assess the tensile and impact strength of a color modified heat cure acrylic resin reinforced with TiO2 nanoparticles. MATERIAL AND METHODS: In this in vitroexperimental study, 1wt% TiO2 nanoparticles were added to SR Triplex Hot heat-cure acrylic resin powder and mixed. Pigments and color fibers were also added and 18 samples were fabricated of this paste for tensile and impact strength testing (n=9) according to ISO5271. Eighteen control samples were also fabricated from the acrylic powder without any modification. Independent t-test was used for data analysis (P< 0.05). RESULTS: The mean tensile strength of the reinforced group was found to be significantly higher (difference of 11 MPa) than that of the control group (P=0.001). The mean impact strength of the reinforced group was 7 MPa higher than that of the control group and this difference was statistically significant as well (P=0.001). CONCLUSIONS: The color modified acrylic resin reinforced with 1wt% TiO2 showed significantly higher tensile and impact strength compared to the conventional acrylic resin. Thus, TiO2 nanoparticles may be incorporated into color-modified acrylic resin powder to enhance its tensile and impact strength, given that they have no adverse effect on other properties. Key words:Tensile strength, acrylic resins, titanium dioxide, impact strength.