Fabrication and bioactivity of porous hydroxyapatite coating on titanium

Chitosan/hydroxyapatite (CS/HA) composite coating was fabricated on pure titanium substrate surface by the electrophoretic deposition, and porous HA coating was obtained by sintering treatment process. The surface morphology and phase composition of the porous HA coating were characterized by SEM and XRD, respectively. The bonding strength between the coating and the substrate was measured by a shear strength test, while the bioactivity of the coating was determined by immersion in simulated body fluid (SBF). The results show that the porous HA coating can be obtained by sintering at 700℃ from the CS/HA composite coating  fabricated in CS/HA suspension with 1∶1 mass ratio of CS/HA, with macro-pore diameter about 10~25 μm and bonding strength up to 19.5 MPa. The coating surface is covered totally by carbonate-apatite after immersion in 1.5 times ion concentration of SBF (1.5SBF) for 5 days, indicating that the coating has a good bioactivity on its surface.