The present invention is related to an osteogenic device and its preparation. Said device comprises a bone morphogenetic protein (BMP), preferably a modified BMP complex obtainable by a modification of the conventional guanidum hydrochloride extraction method and collagens, preferably collagen I or collagen IV, impregnated in and/or adsorbed on a bioceramic carrier, preferably a shapable body (block) originating from a coral skeleton. The method of isolating said modified BMP complex which lacks an immunogenic component and consists essentially of a 100 700 kD and a 15 25 kD protein with osteoinductive properties and preferably of the 15 25 kD protein which has improved storage properties as well as its use in the osteogenic device with improved osteoinductive properties is also disclosed.