BONE HEALING AFTER IMPLANTATION OF HYDROXYAPATITE GRANULES AND BLOCKS(INTERPORE-200(R)) COMBINED WITH AUTOLYZED ANTIGEN-EXTRACTED ALLOGENEIC BONE AND FIBRIN GLUE - EXPERIMENTAL STUDIES ON ADULT-RABBITS

Bone healing around hydroxyapatite granules and blocks (Interpore 200( R)), implanted in mandibular and tibial bone cavities with or without autolyzed, antigen-extracted, allogeneic (AAA) bone, was studied in yo ung adult rabbits. The study was done in two series. In series I, stan dardized bone cavities were filled with implants in granular form mixe d with a fibrin glue, Tisseel(R), for half of the cavities. The animal s were followed for 5 and 8 weeks. In all cavities implanted with AAA bone, regardless of the combination with hydroxyapatite or the fibrin glue, bone had formed in excess of the cavities, resembling exostosis formation. AAA bone significantly increased (P < 0.005 or 0.01) bone f ormation. In series II, a 6 x 3-mm cavity was created in the medial as pect of the proximal part of each tibia. This was filled with a hydrox yapatite block - its cross section measuring 6 x 3 mm - such that 2 mm of the block extended outside the bone surface. In alternation betwee n left and right sides, half of the blocks were covered with a paste o f AAA bone and Tisseel, and half with Tisseel with the fibrin glue alo ne. The observation time was 8 weeks. The area of newly formed bone wi thin and around the hydroxyapatite blocks was significantly increased (P < 0.001) when AAA bone was used. Thus, hydroxyapatite, both as gran ules and blocks for supporting structures, can be successfully combine d with AAA bone, the bone-inductive capacity of AAA bone being utilize d.