Читать книгу Bone and Soft Tissue Augmentation in Implantology - Группа авторов - Страница 20

Based on the principles of the bony lid technique, Khoury went on to harvest monocortical bone blocks with the MicroSaw, especially from the retromolar area.⁶⁹ The bone blocks were longitudinally split and thinned with a bone scraper, gaining at the same time a significant quantity of autogenous bone chips. The thin bone blocks were then stabilized at a distance from the alveolar crest with micro screws to recreate alveolar ridges with sufficient volume and thickness, especially for vertical bone augmentation, and allowing for later implant placement in the prosthetically required position. The space between the thin bone blocks and the remaining alveolar crest was filled with the scraped autogenous bone chips. After 3 months, the implants were inserted into the grafted area^70,72 (see Chapter 4). After 3 months of healing, the grafted area was exposed, and the height and width of the grafted area measured. At the same time, bone cores from the planned implant site were removed for histology and histomorphometry using trephine burs (Fig 1-9). The mean bone resorption was 3.9% in the vertical and 7.2% in the horizontal dimension at the time of implant insertion in the case of 3D vertical augmentation in the posterior maxilla. After 10 years of observation, the mean vertical bone resorption measured on the radiographs was 8.3%. The core biopsies obtained prior to implant placement in the two-stage approach show larger (Fig 1-10a to c) and smaller (Fig 1-11a to c) bone chips, which now are integrated into the new bone. Noticeably, the bone surface is not occupied by multinucleated cells, and new bone formation is obvious, making the augmented area ideal for supporting the process of osseointegration of dental implants. This explains the long-term stability of the vertical grafted area with the osseointegrated implants.

Fig 1-9 Biopsy from the split bone block (SBB) technique. The space between the thin bone blocks and the remaining alveolar crest was filled with the scraped autogenous bone chips. After 3 months, the implants were inserted in the grafted area.^70,72 After 3 months of healing, bone cores from the planned implant site were removed for histology. In this image, the new bone is stained purple, while the old pristine bone and the transplanted bone chips are pink.

Fig 1-10a to c New bone formation on the surface of transplanted bone chips. In the SBB technique, scraped autogenous bone chips fill the space between the cortical bone blocks. After 3 months, healing bone cores from the future implant site were removed. The new bone is stained purple, while the transplanted bone chips are pink. Note the cement lines of the transplanted bone, which are signs of previous bone remodeling. Osteocyte lacunae are either empty or filled.

Fig 1-11a to c New bone formation on the surface of transplanted bone chips. Scraped bone chips can have various shapes and may even resemble bone dust. In the SBB technique, after 3 months of healing, the bone chips are covered by new bone and no obvious signs of resorption are visible.