Maxillary sinus floor elevation using a tissue-engineered bone complex with OsteoBone and bMSCs in rabbits

To evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex with OsteoBone(trade mark) and bone marrow stromal cells (bMSCs) in rabbits.

Autologous bMSCs from adult New Zealand rabbits were cultured and combined with OsteoBone(trade mark) at a concentration of 20 x 10(6) cells/ml in vitro. Twenty-four animals were used and randomly allocated into groups. For each time point, 16 maxillary sinus floor elevation surgeries were made bilaterally in eight animals and randomly repaired by bMSCs/material (i.e. OsteoBone), material, autogenous bone and blood clot (n=4 per group). A polychrome sequential fluorescent labeling was also performed post-operatively. The animals were sacrificed 2, 4 and 8 weeks after the procedure and evaluated histologically as well as histomorphometrically.

New bone area significantly decreased from weeks 2 to 8 in the blood clot group, while bone area in the autologous bone reduced from weeks 4 to 8. In both groups, a significant amount of fatty tissue appeared at week 8. Accordingly, augmented height in both groups was also significantly decreased from weeks 2 to 8. The bone area in the material-alone group as well as in the bMSCs/material group, on the other hand, increased over time. Significantly more newly formed bone area and mineralization was observed in the center of the raised space in the bMSCs/material group than in the material-alone group. The augmented height was maintained in these two groups throughout the course of this study.

These results suggest that OsteoBone can successfully be used as a bone graft substitute and that the combination of this material with bMSCs can effectively promote new bone formation in sinus elevation.