Some ceramics bond to living bone through a bonelike apatite layer for
med 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 al
so induce apatite nucleation. On the basis of these findings, a boneli
ke apatite layer can be formed even on metals such as silicon, titaniu
m and its alloys, tantalum, and organic polymers such as poly(ethylene
terephthalate), poly ether sulfone and polyethylene in a simulated bo
dy fluid with ion concentrations nearly equal to those of human blood
plasma, when their surfaces are a little modified. (C) 1998 Acta Metal
lurgica Inc.