Development of sputtered nanoscale titanium oxide coating on osseointegrated implant devices and their biological evaluation

Nanoscale titanium oxide (TiO2) coating was deposited on titanium (Ti) disks and Ti dental implants using r.f. magnetron sputtering technique. The coating was characterized using grazing angle X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measurement, profilometry and nano-scratch test. The coating also was evaluated with in vitro cell culture and in vivo dog femur model. Three groups of samples were prepared, including as-sputtered Ti (AS-Ti), sputtered Ti with a post-deposition heat treatment at 600 °C (SH-Ti) and machined Ti (MA-Ti) as controls. The AS-Ti and SH-Ti were dense surfaces consisting of nanoscale grains of 40 nm and 80 nm, respectively. Post-deposition heat treatment increased the coating adhesion. The SH-Ti and AS-Ti significantly decreased the water contact angles compared to the MA-Ti. The nanoscale AS-Ti and SH-Ti significantly improved cell adhesion within the first hour of incubation compared with the MA-Ti. No significant differences were observed in osteoblast proliferation and differentiation in vitro as well as reverse torque and histology in vivo among the three groups. In the present study, it was not observed that the nanoscale dense TiO2 coating improved the osseointegration compared to the microscale dense Ti.