The correlation of bone mineral density and histologic data in the early grafted maxillary sinus: a preliminary report.

PURPOSE: : Implant success in the grafted maxillary sinus is dependent on the formation of new vital autogenous bone and its mineral density. Different bone graft materials and graft combinations have been used in the sinus augmentation procedure to support dental implants under occlusal loads. The goal of this study was to determine whether it is possible to observe a direct correlation between bone mineral density and histologic data in the grafted maxillary sinus. Based on the observed histological findings, we propose a bone mineral density classification that has 3 rather than 4 types of bone.

MATERIALS AND METHODS: : A total of 15 patients participated in this study, all of which had only 1 sinus grafted. A total of 34 dental implants were placed in the grafted sinuses. In 7 patients, designated as group A, a 50:50 composite ratio of autogenous and allogeneic bone was used to graft the sinuses. Four patients had the sinuses grafted with a 50:50 composite ratio of a naturally occurring marine algae hydroxyapatite graft material and autogenous bone. One patient had the sinus grafted with 100% autogenous bone. In this group of patients, a total of 25 dental implants were surgically placed 14 to 20 weeks after sinus grafting. The implants were restored 12 weeks later. No implant failures were observed over a 52-week period. The last 3 patients, designated as group B, completed implant surgery beyond the 52-week end point of the study for various reasons. They provided a unique opportunity to histologically observe bone maturation at 68, 88, and 260 weeks, respectively. Using cone beam computed tomography (CT) technology and 3D-CT interactive software, bone mineral density in Hounsfield unit values were recorded during different healing time periods.

RESULTS: : In all 15 patients, bone mineral density was observed to steadily increase during the 52-week observation period and beyond, as evidenced by the increase in Hounsfield unit values and the formation of new, vital autogenous trabecular bone.

CONCLUSION: : Histologic and histomorphometric data demonstrate a definite correlation with the formation of new, vital autogenous trabecular bone and bone mineral density (quality) that permits early loading of implants in the grafted maxillary sinus.