Block augmentation - autologous blocks
Transplants are typically fixed with osteosynthesis screws to the augmentation site. In general, intraorally harvested bone blocks show a lower resorption compared to transplants from the iliac crest; however, they also provide a significantly lower bone volume. Owing to its osteogenic and osteoinductive properties, autologous bone is an ideal scaffold for bone regeneration, e.g. even extensive vertical defects can be treated. In this case, the rapid incorporation of the blocks allows an early implantation, often after only 3–4 months. Today, modern instruments facilitate the harvesting procedure; microsaws and piezosurgical devices, for instance, allow the surgeon to perform a precise cut, resulting in less bone loss and surgical trauma to the donor site. After block harvesting, the donor site can be filled with a collagen sponge (Jason® fleece) to support hemostasis.
After fixing the blocks to the recipient site, the area around the block may be filled with a bone graft material. A low resorbable material, such as bovine bone cerabone®, can help prevent the fast resorption of the bone block. Notably, comparative studies have shown that less resorption occurs when the blocks are covered with a membrane such as the collprotect® membrane.