Corrosion Resistance and Biocompatibility of Titanium Surface with TiO₂-Network Structure

Objectives: The purpose of study was to investigate the corrosion resistance and biocompatibility of anodized titanium (Ti) surface for dental implant application. Methods: Electrochemical anodization treatment was applied to the ground Ti (commercially pure; grade 2) in alkaline solution to rapidly produce a TiO₂-network surface layer. The corrosion resistance of the anodized Ti was evaluated using potentiodynamic polarization curve measurement in acidic artificial saliva with and without fluoride ions. The bacteria attachment and cells adhesion of the test Ti specimens were evaluated using Gram stain method and cell morphology observation, respectively. In this study, two different kinds of oral bacteria, Streptococcus mutans (ATCC 25175) and Streptococcus salivarius (ATCC 13419), and two different kinds of cells, osteoblast-like MG-63 cells and human bone marrow mesenchymal stem cells, were used. Results: Results showed that the anodized Ti with anatase TiO₂ nano-network surface layer (few hundreds nm in thickness) had higher corrosion potential and lower passive current density than the untreated ground Ti surface in artificial saliva with and without fluoride ions. Comparing with the untreated Ti, the anodized Ti had less bacteria attachment and better cells adhesion/spreading morphology. Conclusion: We would conclude that the formation of nano-scaled TiO₂-network surface layer could improve the initial corrosion resistance and biocompatibility of pure Ti for dental implant application.