A new double-layer hydroxyapatite/alumina-silica coated titanium implants using plasma spray technique

There have been several attempts to modify the surface characteristics of tissue engineering implants in order to stimulate specific characteristics. In this research, a single layer of hydroxyapatite (HA) and a new double-layer of HA/Al2O3-SiO2 nanocomposites (SiO2, 10, 20, 30 wt%) were deposited, respectively, on the surface of titanium implants by a plasma spray technique. The results indicated that the applied coating systems featured some specific characteristics on the surface such as higher surface roughness and hydrophilicity resulting in a better cellular response and apatite forming ability in vitro, compared to the bare titanium sample. In addition, among different applied coating, the double layer plasma-sprayed HA/Al2O3-20%wt SiO2 coating has shown an enhanced cellular behavior and biocompatibility compared to the single-layer HA. In conclusion, the new bi-layer coatings could significantly affect the surface characteristics of the implants for better biological response without deteriorating the basic characteristics of the implants.