SHORT-TERM HEALING OF AUTOGENOUS AND ALLOGENEIC BONE-GRAFTS AFTER SINUS AUGMENTATION - A REPORT OF 2 CASES

SINUS AUGMENTATION TO FACILITATE the placement of cylindrical endosseo us implants in the posterior maxilla has become more commonplace, and many different materials have been used for the sinus graft. The resul ts of two sinus augmentation procedures, one grafted with demineralize d freeze-dried bone (DFDB) and the other with autogenous iliac bone, a re presented. Bone cores were obtained with a trephine drill from the grafted regions at the time of implant placement. Eight implants were placed into the grafted areas in each subject. The sample from the sin us grafted with autogenous bone was obtained 8 months postoperatively and the bone core from the sinus grafted with DFDB was taken 16 months postoperatively. The bone specimens were subsequently examined under light microscopy. The autogenous specimens demonstrated new bone forma tion with increased quantity and improved quality when compared to the specimens obtained from the sites grafted with allogeneic bone. All 8 implants placed into the autogenous grafts were clinically osseointeg rated at stage 2. At 16-months postsurgery, the bone core taken from t he site grafted with DFDB demonstrated poor bone quality and still con tained remnants of the graft material in the region approximating the sinus membrane. Two of the 8 implants placed into the allogeneic graft s failed at stage 2. These findings suggest that autogenous sinus graf ts produce bone of adequate quantity and quality for implant placement , whereas DFDB sinus grafts are not completely remodeled by the host a nd may produce bone of insufficient quality and quantity for predictab le implant placement.