title: Bactericidal effect of photocatalytically-active nanostructured TiO2surfaces on biofilms of the early oral colonizer, Streptococcus oralis.
abstract: This study evaluated the photocatalytic bactericidal effect of nanostructured anatase-rich titanium dioxide (TiO2) on microbial biofilms. Commercially pure titanium discs were spin-coated with photocatalytic TiO2nanoparticles (P25). Uncoated discs were used as control (CTRL). Half of the CTRL and half of the P25-coated surfaces were coated with purified saliva (SAL) to give four different groups (CTRL, CTRL + SAL, P25 and P25 + SAL). Streptococcus oralis were allowed to form biofilms on the discs for 18 h and non-adherent cells were rinsed off. Bacterial viability was assessed at time 0 with Live/Dead BacLight staining and epifluorescence microscopy. The remaining discs were divided into a non-UV group and UVA-irradiated (+UV) group (irradiation time, 6 or 24 h). Thereafter, viability was assessed as above. Viability at time 0 was high and no dead cells were seen on any of the surfaces, even after 24 h, in the absence of UVA. However, after 24 h of exposure, the proportion of viable cells was reduced by 40% on the P25 discs compared to 0 and 6 h, and this effect was enhanced with a salivary pellicle. Members of mixed species biofilms differ in their susceptibility to the bactericidal effect of the surfaces tested and further investigations are needed to optimize the conditions. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2321-2328, 2017.
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Westas
authors.affiliation: Department of Prosthodontics, Faculty ofOdontology, Malmö University, Malmö, Sweden.
authors.forename: Mariko
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Prosthodontics, Faculty ofOdontology, Malmö University, Malmö, Sweden.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cecchinato
authors.affiliation: Department of Prosthodontics, Faculty ofOdontology, Malmö University, Malmö, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
authors.affiliation: Department of Chemical and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
authors.forename: Martin
authors.initials: M
authors.lastname: Andersson
authors.affiliation: Department of Oral and Maxillofacial Surgery and Oral Medicine, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ryo
authors.identifier: http://orcid.org/0000-0003-1945-1074
authors.initials: R
authors.lastname: Jimbo
authors.affiliation: Department of Oral Biology, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Davies
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry* / Q000494:pharmacology*; D001672:Biocompatible Materials / Q000737:chemistry / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects* / Q000528:radiation effects; D002384:Catalysis; D006801:Humans; D049329:Nanostructures / Q000737:chemistry*; D013290:Streptococcal Infections / Q000517:prevention & control; D019533:Streptococcus oralis / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D000900:Anti-Bacterial Agents; D001672:Biocompatible Materials; C009495:titanium dioxide; D014025:Titanium
keywords: bactericidal effect; biofilm; photocatalyst; titanium implant; ultraviolet A