ABSTRACT
The use of nanoparticles in improvement antibacterial property of dental resins is one of the most important issues in recent studies. Studies which added these particles to resin materials have reported desirable results in decreasing bacteria's growth. Titanium dioxide nanoparticles have been proposed for reinforcing fillers in dental resin composites and epoxy. The aim of this study was to evaluate the effect of adding titanium dioxide nanoparticles into a light cure glass ionomer on antibacterial properties of this resin against streptococcus mutans. In this in-vitro study, samples were divided into 5 light cure glass ionomergroups which contain respectively of 0 [as control group], 0.5, 1, 3, 5 weight percentage of nano-titanium dioxide. 15 discs [3 from each experimental group] were cured in plastic frames with 2mm thickness and 8mm diameter, for disc diffusion test. Then antibacterial properties against streptococcus mutans were studied in chocolate agar culture. For Direct Contact Test, 15 micro-tubes containing resin groups [3 discs from each experimental group] were prepared and their antibacterial effect were evaluated after 3, 6 and 24 hours. The data was analyzed by Kruskal-Wallis Test and Mann-Whitney Test. In Disc Diffusion Test the amount of antibacterial effect around discs, containing 0.5 nanoparticles was similar to halo around the other discs containing nanoparticles, and it was little more than control group. In Direct Contact Test, glass ionomers containing nanoparticles, number of bacteria was diminished on surface of resin groups that contain more percentages of nanoparticles at 3, 6, 24 hours,. Four experimental groups did not reveal any significant difference, but it was diminished in compare to control group. However the growth of bacteria in both tests in comparison with control group was decreased, antibacterial property of samples that contain nanoparticles doesn't show any significant difference. This property was more significant in direct contact with bacteria