A beautifully done study published in the recent issue of the Journal of Periodontology compared the gingival response to sockets grafted with cadaver bone grafts and non-grafted sites. Follow the link to see the article:
The gingiva over cadaver bone grafts was found to be ischemic and inflamed for the duration of the study. However, the gingiva over non-grafted sites resulted in the gingiva returning to normal pre-treatment physiology. While the authors did not attempt to explain how cadaver bone grafts cause this response, we will use our findings to help explain the study findings.
The findings of ischemia over cadaver grafts is simply a result of the type of bone that provides vascularity to the overlying gingiva. If the underlying bone has poor vascular supply, then the gingiva will have poor vascular supply. Cadaver bone grafts produce sclerotic bone and one of the pathognomonic features of sclerotic bone is a significant reduction in vascularity. Anyone who has laid a flap knows that the alveolar crest bleeds when exposed. If the vascular supply that is coming from the bone is impaired, then of course the gingiva will exhibit ischemia. Histology of sites grafted with cadaver bone grafts illustrate this point.
The following histology is of a site that was grafted with an allograft, 6 months post-op. While a large portion of the site is filled with residual graft particles, the main feature is the lack of blood supply. The particles are encased in sclerotic bone without any recognizable vascular supply.