Читать книгу Bone and Soft Tissue Augmentation in Implantology - Группа авторов - Страница 18

Even though there is a long tradition of considering autologous bone a gold standard, this claim needs to be specified. Bone transplantation dates back to 1879, when a bone allograft was performed on a 3-year-old boy affected by a huge humeral bone loss.³⁶ Reviews such as the one by Albee in 1930² are worth reading from an orthopedic perspective.² From back in the pioneer days to today, the primary intention of bone grafting was to allow the replacement of missing bone in defects of critical size.¹⁰³ In implant dentistry, starting in the 1980s, bone grafts harvested from the ilium and the mandible were used to reverse alveolar atrophy of the maxilla and mandible.¹²⁴ At that time, bone regeneration with autografts was also being compared to those filled with bone substitutes.

Preclinical research in pig mandibular defects convincingly showed that, after 2 weeks, almost twice as much new bone formation had occurred in the presence of autologous bone chips compared with bone substitutes;^16,59,60 however, this does not necessarily mean that autograft bone chips support bone formation. In the same model, when defects were foiled with corticocancellous blocks particulated by a bone mill, bone scraper, piezosurgery, and bone slurry, bone formation at 1 week was restricted to the borders of the defect, making a total of 3% to 4% of new bone; no bone formation was observed in the center of the defect.¹⁰⁰ Bone chips that filled around 20% to 30% of the area were significantly covered by osteoclasts.¹⁰⁰ After 2 weeks, bone formation had increased, covering 20% to 30% of the defect area, while within only 1 week, 20% to 40% of the bone chips were resorbed.¹⁰⁰ This dynamic phase of graft resorption followed by extensive bone formation continues after 4 and 8 weeks, albeit slowing down overall. The low resorption and the favorable osteogenic potential of autographs is supported by the research of the editor of this book.