Abstract: The invention relations to a hydroxylapatite gel obtained through a sol-gel process, in which an alkaline aqueous solution of a calcium salt is reacted with an alkaline aqueous solution of a phosphate salt in a calcium and phosphorous molar ratio in the range of 1.67 to obtain a sol. The sol is then transformed into a gel by hydrothermal treatment. The hydroxylapatite gel thus obtained exhibits excellent properties for use as a binding agent in moldable hydroxylapatite materials, comprising a granular filling material containing calcium in addition to the gel. The filling material is also preferably a hydroxylapatite material. Shaped bodies can be obtained from the hydroxylapatite material, which are most suitable for use in bone surgery as filtering materials. The invention further relates to a metal implant comprising a coating of the inventive hydroxylapatite material. The invention also concerns a method for producing the hydroxylapatite gel, the shaped bodies and the coated metal implant.

Abstract: A bone growth promoting composition, comprising a content of at least one substance from the group consisting of the growth factors FGF, TGF-.beta., IGF-II, PDGF and biologically active mutants and fragments thereof and bone extracts with the corresponding activity as well as a bone extract with BMP activity. In combination with an appropriate application material, the use of the composition in the preparation of implant material is also described.

Abstract: A process is disclosed for the preparation of a hydroxyl apatite material by means of hydrothermal conversion using as starting material a calcitic skeleton which has been purified of organic substances. The conversion is carried out under saturated steam pressure, preferably at a temperature in the range of from 100.degree. C. to 250.degree. C. The influence of the reaction, or rather the defect density of the materials is preferably achieved by the addition of fluoride ions. In addition, the adaption of the material to differing implantation areas as hard tissue replacements as well as the preparation of workable compact implants is described.

Abstract: A porous hydroxyl apatite material is disclosed which is made from calcium-rich basic skeletons of lime-encrusting algae converted into hydroxyl apatite and which serves for use as artificial bone, artificial tooth root, augmentation material, stabilization material, artificial hollow bodies or defect filling material.