rhBMP2 confined by imperforate titanium shell over high profile implants

Purpose: To evaluate the use of a non perforated titanium occlusive device over BMP-2/ACS used to graft high profile dental implants in rabbit tibia. Materials and Methods: 8 New Zealand white rabbits were used in an experiment in which high profile implants were placed in four groups of two each: control, titanium shell only, titanium shell over buffered collagen and titanium shell over BMP-2/ACS. Two animals in each group were sacrificed at 3 weeks and after 6 weeks. Calcified and non-decalcified histology was carried out to evaluate the presence of bone formation and osseointegration. Results: Three of the 8 animals developed tibia fractures. The two BMP-2 test animal tibias remained intact with the 3 week specimen showing very little bone formation inside or outside of the titanium chamber, the six week specimen mostly showing bone outside of the chamber. Conclusion: BMP-2 placed beneath an occlusive non-perforated titanium shell did not form significant bone beneath the titanium shell.