The use of autologous bone grafts for ridge augmentation is widely accepted. However, the development of other bone graft substitutes reduced the importance of the site from which grafting material is taken.
Allogeneic bone grafts are a potential alternative. The variables that may influence the results of allogeneic bone grafts, are whether the grafts are cortical or cancellous, chips or blocks, undecalcified or fully decalcified, deep freeting or
freeze-dried, etc..
In an experimental study of the femurs of rabbits on which the onlay undecalcified cortical bone grafts were performed, we observed the histologic differences between deep forzen and freeze-dried cortical allogeneic bone grafts on the healing and
repair
processes. These results can be compared to those from autologous bone grafts.
@ES The from autologous bone were:
@EN 1. The inflammatory reaction with macrophages and lymphocytes were observed in the first week, but disappeared before 4 weeks. The inflammatory reaction was more severe in the deep frozen group.
In the freeze-dried group, the bony union was earlier than the deep frozen group.
The osteoblastic activity of grafts increased for the first 6 weeks then decreased slightly by 8 weeks. Osteoblasts were more active in the autologous and freeze-dried groups.
New bone formation was slower in the deep frozen group in the first two weeks, but after two weeks there were no distinguishable differences between the groups.
The bone resorptions around the grafts continued far 6 weeks after the operation. The bone resorptions were greater in the deep frozen group.
More capillary proliferations in the intersurfaces and grafts were observed in the autologous and freeze-dried group.
In the results as written above, the freeze-dried group was superior to deep frozen group in the healing process, but in fact, there were considered that the undecalcified, freeze-dried or deep frozen allogeneic bones could be used in the onlay
graft
for augmentation of jaws.
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