Patients from multicenters were treated with sinus lift graft operations and placement of implants. Surgical procedures healed uneventfully with minimum pain, swelling, or morbidity. Grafts healed with few complications or failures. Implants placed into the grafts support prosthetic reconstruction and are predictable over time. The question of what graft material to use is discussed. Grafts of non-resorbable HA (Interpore 200), bovine cortical HA (Bio-Oss), resorbable HA (OsteoGen), and freeze-dried demineralized bone powder and granules are presented. Results of biopsy, histometry, backscattered electron microscopy, cell labeling, and special stain suggest consistent bone growth into a variety of graft materials. In the authors' opinion investigation must continue to 1. Determine the healing time for different graft materials. At present, anecdotal evidence suggests that sinus grafts of autogenous bone heal for 4 to 6 months; freeze-dried demineralized bone heals for 12 to 16 months; and alloplastic materials with freeze-dried demineralized bone heal for 9 to 11 months. 2. Evaluate histologic evidence of bone growth into different bone replacement graft materials. 3. Evaluate the long-term follow-up and success of implants placed within sinus grafts. 4. Determine the remodeling potential of different hard tissue graft materials under implant functional loads.