Prehardened medical-grade calcium sulfate hemihydrate was placed as a grafting material for sinus floor elevation in the left posterior maxilla. After 8 months of healing, three titanium plasma-sprayed screw implants (Biolock) were placed. At the same time, a bone biopsy was harvested for histologic evaluation. The specimen was processed according to standard techniques for hard tissue histology. In both the grafted area and the previously existing area of sinus floor, the histology showed complete calcium sulfate resorption and the bone was primarily of lamellar structure. In the 5-month radiograph, a new trabecular design appeared from the periphery of the grafted area, and on the 8-month radiograph, the graft material was no longer detectable and the augmented area was filled by new tissue showing a trabecular design. This case report documented that medicalgrade calcium sulfate hemihydrate, when used as a grafting material for augmentation of the sinus floor, may lead to proper osseointegration of dental implants.