BONE AUGMENTATION AT TITANIUM IMPLANTS USING AUTOLOGOUS BONE-GRAFTS AND A BIORESORBABLE BARRIER - AN EXPERIMENTAL-STUDY IN THE RABBIT TIBIA

The aim of the present investigation was to compare the effect of usin g autologous bone particles covered with a bioresorbable matrix barrie r with the use of bone particles alone on bone augmentation at titaniu m implants installed in the rabbit tibia. Two Branemark System(R) impl ants, one in each tibia, were inserted in each of 9 rabbits in such a way that 5 threads were not covered with bone. Autologous bone particl es were harvested from the skull and placed over the exposed implant s urfaces on each tibia. The bone graft on one tibia was covered with a Guidor(R) Matrix Barrier, while the bone graft on the other tibia serv ed as a control. After a healing period of 12 weeks, the animals were sacrificed and specimens taken for histomorphometrical analyses. The a nalyses showed that a significantly larger volume of augmented bone ti ssue had formed at the test sites. There were, however, no differences in the amount of mineralized bone. In fact, the difference in tissue volume was due to an increased amount of bone marrow at the test sites . The degree of mineralized bone to implant contact as well as the deg ree of mineralized bone within the threads at the test implants were s imilar to that at the controls. In conclusion, it was found that the c overage of particulate autologous bone grafts with a bioresorbable bar rier resulted in a larger volume of augmented bone than the use of bon e grafts not covered with a barrier.