a natural mineral structure that closely resembles the crystal lattice structure of calcium & phosphorus in bones & teeth. It has been used for many years in surgery to augment the facial bones. Bone adjacent to the hydroxyapatite grows into the material eventually replacing it with viable bone.
The material is available as a slurry or as blocks. It is difficult to work with as it is virtually impossible to pass the slurry through a syringe. The slurry has to be spread like spackle or peanut butter. Additionally, the shape of the slurry can change in the first few weeks after placement. Thus, one has to repeatedly push it with fingers to maintain the desired shape. The blocks are brittle and hard to shape without cracking. The blocks though make ideal interposition grafts between 2 adjacent edges of bone when bone lengthening is desired.