Surface modification of zirconium implants via electrochemical anodization and wet chemical techniques

Metals such as titanium (Ti) and zirconium (Zr) have been widely applied in the orthopaedic and orthodontic field for construction of joint replacement prostheses and teeth implants due to their lower cytotoxicity, excellent mechanical properties, and corrosion resistance. However, the current 15-20 year life span has been a challenging problem for metal-based orthopedic materials. Limited cytocompatibility properties and osseointegration of implants with surrounding bone has been proposed as one of the leading causes of such limited lifetimes.;To improve the cytocompatibility properties of metal orthopedic implants, nanotechnology has been used to create nano-featured thin oxide films (through electrochemical anodization) on metal surfaces, such as nanotubular arrays. This thesis describes the fabrication of zirconium dioxide (ZrO2) nanotubular arrays on Zr surfaces and several efficient techniques to enhance the biocompatibility of as-formed ZrO2 nanotubular arrays via simple wet chemistry treatments.;A series of highly ordered ZrO2 nanotubular array films with different thickness was synthesized in fluoride containing electrolyte by changing the anodic voltage or anodization period. Geometrical factors such as thickness and diameter of nanotubular openings depend on anodization voltage and anodization period. Mechanical properties such as apparent Young’s modulus, ratio of elastic energy to the total deformation energy, and hardness are highly dependent on thickness but not on diameter of nanotubular openings. Resistance of nanotubular arrays to sliding wear and wear loss of nanotubular arrays vary with the culture used.;Several wet chemical techniques including the evaporation-based immersion technique and accelerated immersion method have been explored and found to enhance considerably the bioactivity of ZrO2 nanotubular arrays by enhancing the capability of formation thereon of the hydroxyapatite (HA) layer in simulated biological culture. In this work, I found that a combination of anodic ZrO2 nanotubular arrays and wet chemical treatment achieves the required significant improvement of bioactivity of Zr implant.