Antibacterial, physical and mechanical properties of flowable resin composites containing zinc oxide nanoparticles

AbstractObjectives m of this study is evaluating the antibacterial activity of resin composites containing ZnO nanoparticles against Streptococcus mutans and examining their physical and mechanical properties. s operties of flowable resin composites containing 0–5 wt.% nano-ZnO are investigated using different tests:A. cterial activity (including agar diffusion test on the cured resins, direct contact test using bacteria in a liquid medium, evaluating the effect of aging while the samples are adjacent to a liquid medium, and scanning electron microscopy (SEM)). ical behavior (including flexural and compressive strength and modulus). aspects (including depth of cure and degree of conversion). on properties (including micro-shear bond strength). s gh the agar diffusion test reveals no significant difference between the groups, the direct contact test demonstrates that by increasing the nanoparticle content, the bacterial growth is significantly diminished (p < 0.05). In the aging test, however, the antibacterial properties reduce significantly (p < 0.05). The flexural strength and compressive modulus remains unchanged by incorporation of nanoparticles (p > 0.05) while the compressive strength and flexural modulus significantly increase (p < 0.05). The ZnO containing resins show significantly lower depth of cure (p < 0.05), and higher bond strength (p < 0.05). There is no significant difference between the degrees of conversion, measured by FTIR technique, of the groups (p > 0.05). icance tion of a dental resin composite with antibacterial activity without significant sacrificing effect on the mechanical properties is desirable in dental material science.