Bioactivity of nanostructure on titanium surface modified by chemical processing at room temperature

Purpose: 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 TiO2 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. Conclusion: 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. (C) 2011 Japan Prosthodontic Society. Published by Elsevier Ireland. All rights reserved.