Comparative Study on Hydroxyapatite Coated Titanium Substrates

Titanium and its alloys have been widely used as implant materials due to their biocompatibility, lightweight nature, high corrosion resistance, wear and fatigue resistance. However, despite their compatibility with the human body, titanium implants often exhibit poor osseointegration and limited bioactivity, which can hinder effective bone bonding and long-term stability. To enhance implant performance, hydroxyapatite (HA) coatings are applied due to their excellent bioactivity, osteo-conductivity, and ability to promote bone integration. This report presents a comparative study on titanium substrates coated using various methods, focusing on the impact of these coatings on surface characteristics. The research investigates HA coatings applied via paint brush and spin coating techniques. Two synthesis methods were explored: a turpentine oil-based HA suspension and a water-based sol-gel process. The effectiveness of these coatings in improving titanium substrate properties for biomedical applications was assessed through surface characterization techniques, including Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Analysis (EDAX), and Contact Angle measurements. Results indicate that the water-based sol-gel method produced a more uniform coating than the turpentine oil suspension, while spin coating offered better adhesion and hydrophilicity compared to the paint brush method. Cytotoxicity evaluation using the Daltons Lymphoma Ascites (DLA) test further supports the suitability of the sol-gel spin coating method for biomedical implant applications.