Nitrogen doped titanium dioxide as an aesthetic antimicrobial filler in dental polymers

Abstract

ObjectiveTo develop an aesthetic resin composite using a nitrogen-doped titanium dioxide (NTiO2) filler that possesses antimicrobial properties against cariogenic bacteria. MethodsN-TiO2 powder was manufactured by calcining commercial TiO2 with urea. Free radical release from the N-TiO2 powder under visible light irradiation was analysed using UV-Vis spectrophotometry. The N-TiO2 powder was incorporated into a dental resin and the photocatalytic activity assessed using a dye under both visible light and dark conditions. Using XTT assay to measure the cellular metabolic activity, the antibacterial properties of the N-TiO2 /resin composite discs were tested using Streptococcus mutans. ResultsDoping nitrogen of TiO2 resulted in a band gap shift towards the visible light spectrum, which enabled the powder to release reactive oxygen species when exposed to visible light. When incorporated into a dental resin, the N-TiO2/resin composite still demonstrated sustained release of reactive oxygen species, maintaining its photocatalytic activity and showing an antibacterial effect towards Streptococcus mutans under visible light conditions. SignificanceN-TiO2 filled resin composite shows great promise as a potential aesthetic resin based adhesive for orthodontic bonding.