Porosity-graded hydroxyapatite ceramics to replace natural bone

Porous hydroxyapatite HA bodies were prepared with an aim to simulate bone tissue morphology. By varying the characteristics of starting L-IA powders and the impregnation strategy of cellulosic sponges with theologically opti mized slurries, a wide range of physico-chemical and mechanical properties of the porous ceramics can be obtained. The samples were characterized micr ostructurally, by density and porosimetry and by mechanical strength. Cylin drical specimens exhibiting a porosity gradient showed a promising behaviou r after implantation in rabbits' femur: newly formed bone grew in tight con tact with the ceramic in a very short time, no modified cells are induced a nd bone tissue fills even the inner pores. (C) 2001 Elsevier Science Ltd. A ll rights reserved.