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

• Published in: Dental materials Vol. 38; no. 1; pp. 147 - 157
• Main Authors: Ahmad Fauzi, N.A., Ireland, A.J., Sherriff, M., Bandara, H.M.H.N., Su, B.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.01.2022; Elsevier BV
• Subjects: Anti-Bacterial Agents - pharmacology; Anti-Infective Agents; Antibacterial activity; Antimicrobial; Antimicrobial agents; Catalytic activity; Composite materials; Controlled release; Cosmetic dentistry; Dental adhesive; Dental cement; Dental materials; Dental restorative materials; Esthetics, Dental; Fillers; Free radicals; Irradiation; Light; Light irradiation; Nitrogen; Nitrogen doped titanium dioxide; Orthodontics; Photocatalysis; Polymers; Powder; Reactive oxygen species; Resins; Spectrophotometry; Streptococcus infections; Streptococcus mutans; Sustained release; Titanium; Titanium - pharmacology; Titanium dioxide; Urea; Antimicrobial; Nitrogen doped titanium dioxide; Orthodontics; Dental adhesive
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2021.10.019

To develop an aesthetic resin composite using a nitrogen-doped titanium dioxide (NTiO2) filler that possesses antimicrobial properties against cariogenic bacteria. N-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. Doping 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. N-TiO2 filled resin composite shows great promise as a potential aesthetic resin based adhesive for orthodontic bonding. •N doping of TiO2 produces a photocatalytic powder under visible light.•Photocatalytic properties of N-TiO2 were maintained following incorporation into a dental resin.•N-TiO2 filled resin is aesthetic.•N-TiO2 filled resin is antibacterial on S. mutans under visible light.