Photocatalytic antibacterial activity of Nb2O5-doped TiO2 films deposited by plasma electrolytic oxidation onto commercially-pure titanium surface.

• Grant number: 17/00314-6
• Support type: Scholarships in Brazil - Master
• Effective date (Start): August 01, 2017
• Effective date (End): February 28, 2019
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Cooperation agreement: Coordination of Improvement of Higher Education Personnel (CAPES)
• Principal researcher: Valentim Adelino Ricardo Barão
• Grantee: Bruna Egumi Nagay
• Home Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Photocatalysis treated with titanium dioxide (TiO2) films has shown antimicrobial potential. However, the photocatalytic effect of TiO2 on multispecies oral biofilms onto titanium surfaces exposed to visible light was not evidenced. Also, it was not demonstrated the plasma electrolytic oxidation (PEO) as a technique with potential to produce Nb2O5-doped TiO2 with photocatalytic effect under visible light. Therefore, the aim of the present study is to evaluate the antimicrobial photocatalytic activity of TiO2 films deposited by PEO onto commercially-pure titanium (cpTi) surface. CpTi discs will be used with different surfaces: (1) machined (control); (2) Nb2O5-doped TiO2. The surfaces of the discs will be characterized by scanning electron microscopy (SEM), profilometry and surface free energy. The composition and phases of oxide layer formed on the surface will be evaluated by means of energy dispersive spectroscopy (EDS) and X-ray diffraction analysis (XRD), respectively. The UV-visible diffuse reflectance spectroscopy will be used to analyze the band gap of the coated samples. The photocatalytic potential of Nb2O5-doped TiO2 films will be determined by the degradation of methylene blue assay. Microbiological analysis will be performed with multispecies biofilm (48 h) composed of Streptococcus sanguinis and Actinomyces naeslundii on different surfaces of cpTi. The colony forming units will be determined by specific mediums (CFU/mL) after application of visible light. SEM images of the biofilm formed on the cpTi discs will be used to investigate the organization of the microorganisms onto each surface. Quantitative data will be submitted to the most appropriate statistical analysis with significance level of 5%. The number of samples for each assay will be determined after the pilot study. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

NAGAY, BRUNA E.; DINI, CAROLINE; CORDEIRO, JAIRO M.; RICOMINI-FILHO, ANTONIO P.; DE AVILA, ERICA D.; RANGEL, ELIDIANE C.; DA CRUZ, NILSON C.; BARAO, VALENTIM A. R. Visible-Light-Induced Photocatalytic and Antibacterial Activity of TiO2 Codoped with Nitrogen and Bismuth: New Perspectives to Control Implant-Biofilm-Related Diseases. ACS APPLIED MATERIALS & INTERFACES, v. 11, n. 20, p. 18186-18202, MAY 22 2019. Web of Science Citations: 0.