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:
Cadaver Bone Grafts ProduceChronic Gingival Ischemia and Erythema
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.
Bio-Oss 10 years after grafting with unrecognizable vascular supply.
The following histology is of a grafted site 6 months post-op using SteinerBio regenerative products. Notice the difference in vascularity and health of the tissues when compared to the cadaver bone grafts. The vascular supply is obvious and extensive with no inflammation. When the graft produces healthy vital bone the overlying gingiva will likewise be normal healthy gingiva.
SteinerBio 6 months after grafting with excellent vascular perfusion and no inflammation.
The histology of the different graft materials gives a clear explanation of why cadaver bone grafts produce chronic ischemia in the gingiva. For a better understanding of why cadaver bone grafts produce ischemia, please view the following:
The second finding of this study is that the gingiva over cadaver bone grafts is chronically inflamed. The answer to that is again simple. If the bone is inflamed, the gingiva will likewise be inflamed. In a study on rabbit tibia, SteinerBio bone grafts and allografts were compared and independently analyzed by a histopathologist. As you can see from the chart below, SteinerBio products were lower in inflammation when compared to the non-grafted sites. Let us repeat that:
The bone produced by SteinerBio bone grafts has lower levels of inflammatory cells than the non-grafted sites.
The reason for this is that our biologically active compound reduces the inflammatory response at the same time it stimulates bone formation. As you can see in the chart, the inflammation produced by mineralized allografts is dramatic. It is easy to understand that when the bone under the gingiva contains inflammation, the gingiva will likewise be inflamed as was found in the study.
Those that support cadaver bone grafts will discount these findings by saying that the inflammation and ischemia will resolve when the the cadaver bone grafts remodel and the cadaver bone graft is resorbed. However, remodeling and resorption of cadaver bone graft particles have never been reported in any research findings. For an understanding of what happens to cadaver bone graft particles over time, please see the following:
So what does the science tell us about our grafting options? Cadaver bone grafts produce chronic gingival inflammation and gingival ischemia. Cadaver bone grafts have been shown to predictably produce marginal bone loss and this has not been found in any resorbable science based bone graft. Cadaver bone grafts are not osteogenic or osteoinductive. Cadaver bone grafts are never fully resorbed and produce sclerotic bone. SteinerBio sceince based bone graft are osteogenic and fully resorbed to produce normal bone. The long-term success rates (three years in function) have been shown to be 88% for Novabone and 100% for SteinerBio. The long-term success of implants placed in sockets grafted with allograft or Bio-Oss has never been published and therefore, is unknown. Cadaver bone grafts have never been shown to outperform any science-based bone graft, but on the other hand, studies have shown science-based bone grafts to outperform cadaver bone grafts. With a few hundred histological studies published on cadaver bone grafts, none of them have ever shown any cadaver bone graft in the process of remodeling and none of them have ever shown normal bone produced. It is remarkable that thousands of learned men and women in the dental profession with no scientific support insist that these graft materials are resorbed and remodeled into normal bone. It is a remarkable case of group think, cognitive bias, and the need to maintain the accepted dogma. For more information, please view the following:
If your patients were informed of the basic scientific facts of the graft materials that are available, they would choose science-based bone grafts.
American Society for Bone and Mineral Research (ASBMR) Tissue Engineering and Regenerative Medicine International Society (TERMIS)