Synthesis and Evaluation of Antibacterial Activity of Silver-Doped Titania Nanoparticles as an Antibacterial Additive to Dental Materials

In this study، antibacterial behavior of nanoparticles of titania and nanoparticles of silver-doped titania were evaluated against Streptococcus mutans and were compared with three pathogen bacteria. Initially، the nanoparticles of titania and nanoparticles of silver-doped titania were synthesized by sol-gel method. The powders were characterized by X-ray diffraction (XRD)، Transmission Electron Microscopy (TEM) and Energy-Dispersive Spectroscopy (EDS) techniques. Then، Agar dilution was used to evaluate antibacterial properties of silver- doped titania nanoparticles against Streptococcus mutans and three types of pathogen bacteria. Phase structure evaluation showed anatase phase of titania in all silver-dopped titania nanoparticles. The particle size of titania and silver particles were determined 30 and 15 nanometers، respectively. The antibacterial results showed that Minimum Inhibition Concentration (MIC) of 3 mg/ml for silver-doped titania nanoparticles with different percentages of silver could inhibit bacteria growth، while nanoparticles of titania in fluorescent light indicated reducing growth of bacteria. Furthermore، MIC of 4 mg/ml was achieved for silver-doped titania nanoparticles with 5 mole percent sliver against the other pathogen bacteria and for other specimens observed growth of bacteria. These results showed that silver could increase antibacterial properties of titania. This is due to presence of silver nanoparticles and also the effect of silver on the photocatalyst properties increased antibacterial properties.