Comparison of histomorphometry and microCT after sinus augmentation using xenografts of different particle sizes in rabbits.

PURPOSE: The aim of the present experiment was to compare the data on new bone formation measured histologically and microtomographically in maxillary sinuses augmented with a xenograft with higher density and higher mineral content compared with the natural bone. The hypothesis was that histomorphometric and micro-computed tomography (microCT) analyses do not yield similar outcomes when a xenograft with higher density and mineral content compared with the natural bone is used.

METHODS

In 18 rabbits, the maxillary sinus was augmented bilaterally using deproteinized bovine bone mineral (DBBM) xenograft granules of either 0.125-1 mm or 1-2 mm of dimensions. The rabbits were euthanized after 2, 4, and 8 weeks of healing. Comparisons were performed between microCT and histological analyses.

RESULTS

After 2 weeks of healing, higher contents of bone were found at the histological compared with the microCT analyses in both sinuses, especially in the middle regions of the grafted sinus. Between 2 and 8 weeks of healing, new bone increased of about 21% at the histological analyses while, at the microCT, increased only about 4%. In the same period, the xenograft proportion decreased from 51.6 ± 4.9 to 45.3 ± 3.3% at the histological analyses while, at the microCT, the xenograft appeared to increase in percentages.

CONCLUSION

Histological and microCT analyses yielded different outcomes when a xenograft with higher density and higher mineral content compared with the natural bone was used.