“…At present, many techniques, such as sol-gel [6], plasma-spray [7][8], pulsed laser deposition [9][10], dipping method [11], thermal spraying [12], hot isostatic pressing [13], electrochemical deposition [14][15], have been proposed offering the potential for better control of the film structure. But the knowledge on bioactive mechanism, whether in experiment or theory, has been far from sufficient, and most of the methods are not satisfactory yet.…”