The biomaterial influences the ossification after sinus floor elevation using tissue-engineered bone grafts

Sinus floor elevation is the standard procedure that allows dental implant insertion in the atrophic posterior maxilla. Instead of autogenous bone, tissue-engineered bone grafts can be used, but clear comparative clinical studies also assessing the influence of the biomaterial are missing. In six patients, tissue-engineered bone grafts were used in eight sinus floor elevations. After culturing osteoblast-like cells from biopsies of the maxilla, they were seeded on scaffolds made either from demineralised bovine bone matrix (DBBM) or from solvent-dehydrated mineralised bone (SDBB), and grafted. In all patients primary wound healing was without complications, except for one patient in the SDBB group. After 12 months, implant insertion was possible only in the SDBB group; in the DBBM group, fibrous connective tissue was found in an attempt of implant insertion. After 5 months, implant placement was performed in one patient of each group. However, the two implants inserted in the DBBM group were lost after 6 weeks. Histology of the bone cores in the DBBM group at 5 months showed lamellar bone and osteoid, and at 12 months showed fibrous connective tissue. Inflammation and some resorption of the scaffold was found 5 months after SDBB grafting, and after 12 months cancellous bone formation encapsulating SDBB remnants were observed. These preliminary data suggest that the preparation method of the bovine bone matrix, in particular the mineral content, and therefore the mechanical stability may have some influence on the generation of new bone.