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Effect of addition of silver nanoparticles on flexural and impact strength of heat cure acrylic resin

B.D.S., Master student at the College of Dentistry, Hawler Medical University. B.D.S., M.Sc., Ph.D., Lecturer at the College of Dentistry, Hawler Medical University. Background and objectives: Heat cure denture base material is the most commonly used material for fabrication of removable prosthesis since its introduction in 1937. The unresolved problem of frequent fracture is one of the main drawbacks when used in denture construction. The purpose of this study was to evaluate the influence of silver nanoparticles on flexural and impact strength of heat-polymerized resin. Materials and methods: Silver nanoparticles were impregnated at 1%, 3% and 5% by weight to the monomer of methyl methacrylate with the aid of probe sonicator. Afterward, they were mixed with the acrylic powder. Sixty samples were prepared in total to observe its influence on flexural and impact strength. Results: Flexural strength values revealed a statistically significant difference (p<0.05) among the three concentrations. The results indicated a 22% reduction in the mean value for 3% while 1% and 5% caused 20% and 21% decrease respectively when compared to control. Regarding impact test, it demonstrated a statistically significant difference only for 5% that caused a drastic drop in impact value by 41% in contrast to the control group. Conclusion: Within the limitations of this study, it can be concluded that the addition of silver nanoparticles caused a reduction in mechanical strength of heat cure acrylic except for 3% which caused a minor non-significant increase in impact strength. Considering the negative effect on mechanical strength and jeopardizing the aesthetic value for acrylic, it can’t be considered as a suitable additive to enhance the properties tested.