Silver doped titanium dioxide nanoparticles as antimicrobial additives to dental polymers.

Objective. The objectives of this in vitro study were to produce a filled resin containing Ag-TiO2 filler particles and to test its antibacterial properties. Methods. Ag-TiO2 particles were manufactured using the ball milling method and incorporated into an epoxy resin using a high speed centrifugal mixer. Using UV/vis spectrophotometry investigations were performed to assess how the photocatalytic properties of the Ag-TiO2 particles are affected when encased in resin. Adopting the bacteria colony counting technique, the antibacterial properties of Ag-TiO2 particles and Ag-TiO2 containing resins were assessed using Streptococcus mutans under varying lighting conditions. Results. Ag doping of TiO2 results in a band gap shift towards the visible spectrum enabling Ag-TiO2 to exhibit photocatalytic properties when exposed to visible light. Small quantities of Ag-TiO2 were able to produce a bactericidal effect when in contact with S. mutans under visible light conditions. When incorporated into the bulk of an epoxy resin, the photocatalytic properties of the Ag-TiO2 particles were significantly reduced. However, a potent bactericidal effect was still achieved against S. mutans. Significance. Ag-TiO2 filled resin shows promising antimicrobial properties, which could potentially be used clinically. (C) 2016 Published by Elsevier Ltd on behalf of The Academy of Dental Materials.