title: Bioactivity of nanostructure on titanium surface modified by chemical processing at room temperature.
abstract: OBJECTIVE
  Recently, there has been considerable interest in finding novel applications and functions for existing dental materials. We found that, at room temperature and atmospheric pressure, titanium oxide spontaneously generates nanostructures very similar to the "nanotubes" created by TiO(2) sputtering. The aim of this study was to evaluate the ability of this surface to affect the cellular osteogenic differentiation response.
  
  
  METHODS
  Titanium disks without and with a 'nanosheet' deposited on their surface were used as the control and test groups, respectively. Cell culture experiments were performed with SD rat bone marrow cells, which were seeded into microplate wells and cultured in media designed to induce osteogenic differentiation. We measured alkaline phosphatase (ALP) activity, osteocalcin (OCN) production, calcium deposition and Runx2 gene expression to assess the levels of differentiation.
  
  
  RESULTS
  After 14 and 21 days, cellular ALP activity was significantly higher in the test group than in the control group. After 28 days, cells in the test group also showed significantly more calcium deposition and OCN production than those in the control group. There was significantly different expression of Runx2 mRNA in the test group compared to the control group after 3 days of culture.
  
  
  CONCLUSIONS
  In conclusion, these data suggest that titanium implants modified by the application of nanostructures promote osteogenic differentiation, and may improve the biointegration of these implants into the alveolar bone.
authors.affiliation: Department of Fixed Prosthodontics and Occlusion, Osaka Dental University, 8-1 Kuzuhahanazonocho, Hirakata, Osaka 573-1121, Japan. komasa-s@cc.osaka-dent.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Komasa
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Taguchi
authors.forename: Hisataka
authors.initials: H
authors.lastname: Nishida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Tanaka
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Kawazoe
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D015921:Dental Implants; D059630:Mesenchymal Stem Cells / Q000502:physiology*; D049329:Nanostructures; D010012:Osteogenesis / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013696:Temperature; D014025:Titanium
chemical_list: D015921:Dental Implants; C009495:titanium dioxide; D014025:Titanium