Assessment of anodized titanium implants bioactivity

Abstract

This study was conducted to create nanostructured surface titanium implants by anodic oxidation process aiming to bring out bioactivity and to assess the resultant bioactivity both in vitro and in vivo. An economic protocol was used to apply anodic spark discharge and create surface nanoporosities on grade II commercially pure titanium (cpTi). The in vitro investigation included morphology, surface chemical analysis, roughness and crystalline structure of titanium oxide (TiO₂) film prepared. Assessment of the bioactivity was carried out by immersing the specimens in simulate body fluid (SBF) and investigating the surface-deposited layer. The in vivo investigation was conducted by surgically placing the anodized implants into rabbits tibia for different healing periods. Then biomechanical evaluation was performed to verify the effect of treatments on the interface resistance to shear force. Routine histological analysis was performed to evaluate the bone tissue reactions to anodized implants. Anodization of titanium implants produced morphological changes, raised the percentage of oxygen in the TiO₂ layer, increased surface area and roughness of implants remarkably, and modified the crystallinity of the film. The in vitro assessments of bioactivity showed that a layer of calcium phosphate was precipitated on the titanium surfaces 7 days after soaking into SBF. The implant-bone interface resistance to shear force was enhanced at 2-week healing period. This was confirmed by histological findings. Nanostructured surface titanium implants could be prepared by anodic oxidation with resultant accelerated bioactivity that may be recommended for early loading.