Bone response to hydroxyapatite particles of different shapes in rabbit tibia.

Four holes drilled in rabbit tibia were filled with different commercial hydroxyapatite products. All particles caused a mild inflammatory reaction, which disappeared in 2 months. The line between the new and original bone was visible even after 6 months. No differences in healing pattern were discovered for the various products. When bone cavities are filled with hydroxyapatite particles, the shape of the particles does not seem to affect the healing process.