OBJECTIVES

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.

MATERIAL AND METHODS

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.

RESULTS

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.

CONCLUSION

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.