Occlusive barriers in combination with particulate Bio-Oss® graft: a pilot study on rabbit calvaria

The aim of this study was to histologically evaluate the potential for vertical bone augmentation of the Bio-Oss® graft compared to a blood clot in conjunction with an occlusive barrier in the rabbit calvaria defect model. Metallic dome shaped barriers with 4.5 mm width and 3.5 mm height were positioned in six adult rabbit skulls. At the right side, the barrier was filled with Bio-Oss®, and the left side was filled with a blood clot. After a healing period of three months, the animals were sacrificed, and the samples were prepared for histological and histomorphometric analyses. The total mineralized area (TMA) as well as the newly formed bone (NBA) was calculated as the percentage of the bone augmentation inside the metallic barriers, and parametric statistical analysis was used to describe the findings. The samples with blood clots exhibited significantly less TMA formation than the Bio-Oss® group. However, the difference in the amount of NBA was not statistically significant. Furthermore, the Bio-Oss® specimens exhibited remaining graft particles within the sample. In conclusion, the barriers filled with Bio-Oss® exhibited significantly higher TMA than those with only blood clots, and the remaining Bio-Oss® particles were integrated into newly formed bone tissue to fill the spaces and promote a greater volume than the samples from the blood clot groups.