Scanning electron micrograph of cells crawling across crystals. Two human bone-forming cells (osteoblasts) crawling over crystals of the ceramic material monetite (CaHPO4). Monetite crystals are electrochemically deposited onto titanium, making the metal more compatible with the body. This can be used in applications such as artificial hip joints and prosthetic tooth-root posts where bone bonding and the stability of the implant are very important. This image demonstrates the coating successfully encouraging cell growth: the cells look normal and are growing well over the surface. Supplied by Karin Hing, courtesy of Wellcome Images.