Algae-derived (phycogene) hydroxylapatite. A comparative histological study [corrected and issued with original...

3 granular hydroxylapatite (HA) biomaterials, solid, coralline and phycogene HA (obtained from calcifying algae), differing widely in their relative amounts of specific surfaces and their origin, were examined with regard to their effects on bone healing in rats. Trephine drill holes were produced in the rat femur and filled with the HA granules. Each biomaterial produced a characteristic pattern of bone healing. Bioceramics with a small surface area showed random bone-implant contacts. Biomaterials offering large surface areas showed a dense bone-implant interface. Evidence is presented to suggest that a large specific surface favours osteoneogenesis and cell spreading on and into an implant.