The aim of this research was to compare 2 different graft materials, -tricalcium phosphate (Cerasorb) and autogenous bone, used in the same patient. Bilateral sinus grafting was performed on 4 selected patients; Cerasorb only was used on the experimental side, and autogenous bone only was used on the control side. In all 4 patients, the maxilla was atrophied to such an extent that the reconstruction included not only sinus grafting but also onlay plasty. The procedure was followed by implant placement 6 months later. In addition to routine panoramic radiographs, 2- and 3-dimensional computed tomographic (CT) examinations were performed pre- and postoperatively and after implantation. Information from CTs is necessary when alveolar bone atrophy is extensive, complications appear probable, and in difficult cases, when exact documentation is important. A total of 16 bone biopsies were taken at the time of implant placement. The histologic and histomorphometric results indicated that when the formation of new bone was slow, it was slow on both sides; when it was fast, then it was fast on both sides. Individual patient factors strongly influenced the fates of the various graft materials in the organism. Comparisons of the present results with the findings of other investigators demonstrated that -tricalcium phosphate is a satisfactory graft material, even without autogenous bone. Schlagwörter: autogenous bone, bone grafting, calcium phosphates, computed tomography, histology, histomorphometry, maxillary sinus