Calvaria And Iliac Crest Bone Grafts: Long-Term Morphostructural Analysis

Objectives: The aim of the study was to evaluate, from a microscopical and morphostructural point of view, the integration of extraoral autologous bone grafts from different donor sites in edentolous area of the jaws. Methods: The donor sites for autologous grafts were Calvaria and Iliac Crest. Samples were withdrawn from the donor sites at the moment of grafts insertion (T0), while samples from regenerated sites were taken four months (T1) and ten years (T2) after grafting. Bone specimens at different experimental times were processed and stained with Hematoxilin-Eosin in order to perform light microscope analysis. Results: Both bone substitutes showed a good integration with the host tissue at light microscope observation. Both samples at T1 showed strong remodeling phenomena, even if in sites regenerated with calvaria grafts a more dynamic aspect could be detected. Moreover, the presence of new blood vessels could be observed in both type of samples. After ten years, both bone grafts appeared well integrated with the host tissue. Once more, the appearance of sites treated with calvaria graft seem to have a better morphology, very similar to native bone tissue. Conclusions: The microscopic observation of bone samples from sites treated with grafts from different sites allowed to evaluate the presence of regenerative and neoangiogenic phenomena. These phenomena, more evident after six months from the grafting, that is at the moment of implant insertion, are important for grafts integration and for the success of further implant therapy. The calvaria graft microscopic aspect at T1 seems to be more organized and regular than that observed in sites regenerated with iliac crest graft at the same experimental time, suggesting a better clinical performance. However, these differences appear much less evident at T2.