Photocatalytical Antibacterial Activity of Mixed-Phase TiO₂Nanocomposite Thin Films againstAggregatibacter actinomycetemcomitans

Abstract

Mixed-phase TiO2 nanocomposite thin films consisting of anatase and rutile prepared on commercially pure Ti sheets via the electrochemical anodization and annealing treatments were investigated in terms of their photocatalytic activity for antibacterial use around dental implants. The resulting films were characterized by scanning electron microscopy (SEM), and X-ray diffraction (XRD). The topology was assessed by White Light Optical Profiling (WLOP) in the Vertical Scanning Interferometer (VSI) mode. Representative height descriptive parameters of roughness R a and R z were calculated. The photocatalytic activity of the resulting TiO2 films was evaluated by the photodegradation of Rhodamine B (RhB) dye solution. The antibacterial ability of the photocatalyst was examined by Aggregatibacter actinomycetemcomitans suspensions in a colony-forming assay. XRD showed that anatase/rutile mixed-phase TiO2 thin films were predominantly in anatase and rutile that were 54.6 wt% and 41.9 wt%, respectively. Craters (2–5 µm) and protruding hills (10–50 µm) on Ti substrates were produced after electrochemical anodization with higher R a and R z surface roughness values. Anatase/rutile mixed-phase TiO2 thin films showed 26% photocatalytic decolorization toward RhB dye solution. The number of colonizing bacteria on anatase/rutile mixed-phase TiO2 thin films was decreased significantly in vitro. The photocatalyst was effective against A. actinomycetemcomitans colonization.

Alkaline phosphatase levels of murine pre-osteoblastic cells on anodized and annealed titanium surfaces

“…Three dimensional images of the surface topography of the Groups Ti and AR at x5.1 magnification are shown in Figure 2. Ra and Rz surface roughness parameters values obtained from the Group AR quantitatively presented higher height descriptive parameters of roughness (9).…”

“…This study was performed at the laboratories of New York University College of Dentistry and was supported by İstanbul University Fund of Scientific Research (BEK-2017-25356). Commercially pure titanium (cpTi) (ASTM B265-02) sheets in squares (10×10×1 mm) were used as substrates for the experiments as described previously by Yeniyol et al (9). The surfaces of the specimens were prepared by standard metallographical techniques.…”

“…The surface topologies of the sheets were investigated with the White Light Optical Profiling (WLOP) Wyko-NT1100 (Veeco Instruments Inc., Plainview, NY, USA) at VSI (Vertical Scanning Interferometer) mode, which is a noncontact optical profiling system that provides high vertical resolution. Two height descriptive parameters of roughness as Rα and Rz were used to quantify the surface roughness (9).…”

“…The scanning data were recorded in the 2θ range of 20–73°. The phase contents of rutile and anatase (% W A ) and rutile (% W R ) for the anatase/rutile mixed-phase TiO 2 thin films at Group AR were estimated by utilizing the obtained patterns to determine weight percentage of the anatase phase and rutile phase TiO 2 using the Spurr–Myers’ equations (9).…”

“…Since the proposition of photocatalytical oxidation by Fujishima and Honda (8), TiO 2 have gained great attention as a promising photocatalyst. The photocatalytic activity of TiO 2 is most significantly influenced by crystalline structure (9). TiO 2 is usually used as a photocatalyst in two crystal structures: rutile and anatase.…”