A comparative study of electrochemical deposition and biomimetic deposition of calcium phosphate on porous titanium

Coating porous titanium with calcium phosphate (Ca-P) is an effective way to enhance titanium's osteoinduction capability. This study investigated the effectiveness of two coating methods: biomimetic deposition (BD) and electrochemical deposition (ED) in aqueous solutions. The titanium surfaces were treated by acidic etching and alkaline before coating. Effects of the pre-coating treatments on Ca-P coating were also investigated. Both deposition methods could produce Ca-P coatings on the inner pore surfaces of the titanium. The BD coatings were thicker and more uniform than were the ED coatings. On the other hand, ED was less sensitive to the condition of the titanium surface, and much faster in the coating deposition. However, ED produces less uniform and thinner coating layers on the inner pore surfaces of the titanium than does BD. The crystal structure of the coating is octacalcium phosphate (OCP) regardless of the deposition method. The morphology of flake-like OCP crystals in the deposition layers is similar for both deposition methods, except that the crystal flakes rupture after ED.