title: Blue-violet laser modification of titania treated titanium: antibacterial and osteo-inductive effects.
abstract: BACKGROUND
  Many studies on surface modifications of titanium have been performed in an attempt to accelerate osseointegration. Recently, anatase titanium dioxide has been found to act as a photocatalyst that expresses antibiotic properties and exhibits hydrophilicity after ultraviolet exposure. A blue-violet semiconductor laser (BV-LD) has been developed as near-ultraviolet light. The purpose of this study was to investigate the effects of exposure to this BV-LD on surface modifications of titanium with the goal of enhancing osteoconductive and antibacterial properties.
  
  
  METHODS
  The surfaces of pure commercial titanium were polished with #800 waterproof polishing papers and were treated with anatase titania solution. Specimens were exposed using BV-LD (λ = 405 nm) or an ultraviolet light-emitting diode (UV-LED, λ = 365 nm) at 6 mW/cm(2) for 3 h. The surface modification was evaluated physically and biologically using the following parameters or tests: surface roughness, surface temperature during exposure, X-ray diffraction (XRD) analysis, contact angle, methylene blue degradation tests, adherence of Porphyromonas gingivalis, osteoblast and fibroblast proliferation, and histological examination after implantation in rats.
  
  
  RESULTS
  No significant changes were found in the surface roughness or XRD profiles after exposure. BV-LD exposure did not raise the surface temperature of titanium. The contact angle was significantly decreased, and methylene blue was significantly degraded. The number of attached P. gingivalis organisms was significantly reduced after BV-LD exposure compared to that in the no exposure group. New bone was observed around exposed specimens in the histological evaluation, and both the bone-to-specimen contact ratio and the new bone area increased significantly in exposed groups.
  
  
  CONCLUSIONS
  This study suggested that exposure of titanium to BV-LD can enhance the osteoconductivity of the titanium surface and induce antibacterial properties, similar to the properties observed following exposure to UV-LED.
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Kawano
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Widyasri
authors.initials: W
authors.lastname: Prananingrum
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Ishida
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Takaharu
authors.initials: T
authors.lastname: Goto
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Yoritoki
authors.initials: Y
authors.lastname: Tomotake
authors.affiliation: Department of Oral & Maxillofacial Prosthodontics and Oral Implantology, The University of Tokushima, Institute of Health, Biosciences, Tokushima, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ichikawa
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents; D001422:Bacterial Adhesion / Q000528:radiation effects; D007834:Lasers; D008297:Male; D051379:Mice; D016348:Osseointegration; D051381:Rats; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D000900:Anti-Bacterial Agents; C009495:titanium dioxide; D014025:Titanium