Bioactive titanium-particle-containing dicalcium silicate coating

Titanium particles with typical size ranging from 80 to 140 μm were used as scaffolds in the synthesis of bioactive dicalcium silicate (finer than 20 μm) coating by atmospheric plasma spraying to improve the physiological chemical bonding between the coating and bone. A bonding strength as high as 49.0 MPa was achieved between the coating and substrate as a result of the high titanium content in the coating and the similar thermal expansion coefficients of the coating and substrate. The favorable bioactivity was also accomplished as revealed by the formation of bone-like hydroxyapatite after immersion in simulated body fluids (SBF) for 7 days. The good biological properties were further demonstrated by adhesion and differentiation of human osteogenetic cells seeded directly on the coating surface. After dissolution experiments conducted in a Tris–HCl solution, very little changes in the mechanical properties were observed demonstrating the good durability of the coating. Our results thus show that the composite coating possesses not only good bioactivity but also long-term durability.