Bone bonding in bioactive glass ceramics combined with bone matrix gelatin

To determine how to encourage inductive osteogenesis on bioactive ceramics and accelerate the bonding of implants to the surrounding bone, we studied the role of autolyzed antigen-extracted allogeneic bone gelatin (AAAG) in bone bonding to bioactive ceramic implants in rabbit tibiae. Smooth-surfaced plates (15 x 10 x 2 mm) of apatite and wollastonite containing glass-ceramic were implanted into the proximal metaphyses of tibiae, with AAAG packed into the medullary cavity in one limb but not in the contralateral limb, which served as a paired control. After 2, 4, 8, 16, and 25 weeks, bone bonding and bone formation at the bone/implant interfaces were evaluated by a detaching test and undecalcified histological examination. The tensile failure load increased from 2 to 25 weeks for both groups. The failure load of the AAAG-treated group was significantly greater than that of the control group at every stage. Histologically, the AAAG-treated specimens showed active new bone formation in the medullary cavity and extensive bonding between the implant and bone at early periods. The percentage of bony covering in the AAAG-treated group was significantly higher than that of the controls at all intervals except at 25 weeks. The results of this study suggest that the addition of osteoinductive AAAG to a bioactive implant may significantly accelerate bone apposition to the implant and improve the bonding process at the interface, which would help to establish an earlier and stronger bonding between the implants and the surrounding bone.