Apatite formation on surfaces of ceramics, metals and polymers in body environment

Some ceramics bond to living bone through a bonelike apatite layer formed on their surfaces in the living body. This apatite is nucleated by Si-OH groups on their surfaces and grows by consuming the calcium and phosphate ions from the body fluid. The Ti-OH and Ta-OH groups can also induce apatite nucleation. On the basis of these findings, a bonelike apatite layer can be formed even on metals such as silicon, titanium and its alloys, tantalum, and organic polymers such as poly(ethylene terephthalate), polyether sulfone and polyethylene in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma, when their surfaces are a little modified.