Thirty-six sinus grafts were performed in 34 patients with an alveolar crest bone height in the posterior maxilla of 3 to 5 mm before grafting. The sinuses were grafted using Bio-Oss alone or mixed with fibrin glue. Group 1 was the control group and included 25 patients who received a xenograft mixed in saline. Group 2 comprised 9 patients who received a xenograft and fibrin glue. The study was further subdivided at the time of 9 months. This histologic study evaluated by hematoxylin-eosin (H&E) and histomorphometric analysis whether fibrin glue in combination with Bio-Oss enhances bone regeneration in sinus floor elevation in humans. The new bone formation was better in Group 2 than in Group 1, but the difference was not significant. The absorption of the graft material was faster in Group 2 than in Group 1, in the short term, but better in Group 1 over the long term, although the difference was not significant. Lamellar bone was formed earlier in Group 1 compared to Group 2, but the difference was not significant. Overall, the surgery site stabilized earlier with new bone formation in Group 2 than in Group 1, but the difference was not significant. Combining a fibrin sealant and Bio-Oss could lead to improved scaffolds for bone tissue engineering based on the synergistic effects of the biomaterials. Therefore, Bio-Oss or Bio-Oss plus Tisseel may be used depending on the situation.