VEGF AND MMPS IN AUTOLOGOUS EXTRAORAL BONE GRAFTS: LONG-TERM INVESTIGATION

Objectives: The aim of this study was to evaluate changes in VEGF and MMPs expression at different times after grafting in extraoral autologous bone grafts from two different donor sites: calvaria and iliac crest. Methods: Calvaria and Iliac Crest bone grafts were used to fill bone defects in edentulous sites, in prediction of implant therapy. Specimens from the donor sites were withdrawn at the moment of grafts insertion (T0), and from regenerated sites six months (T1) and ten years (T2) after grafting. Samples at different experimental times were processed in order to investigate VEGF, MMP2 and MMP9 expression by immunohystochemical analysis. Results: Immunohistochemical analyses showed VEGF, MMP2 and MMP9 significantly increase their expression at T1, while at T2 their expression return to levels comparable to that recorded in specimens from the donor sites (T0). Moreover, in any samples from sites treated with calvaria grafts, all the investigated molecules showed higher levels of expression than in samples from sites regenerated with iliac crest bone grafts. Conclusions: Autologous bone grafts are considered the best biomaterials for pre-prosthetic regenerative techniques, according to their good clinical features and to the elevated success rate associated with their use. In this study, the capability of host tissue integration with the graft was investigated from a microscopical and biological point of view. VEGF and MMPs are known to be involved in the process of neoangiogenesis and revascularization of the graft. Their expression increase after six months from the grafting, that is at the moment of implant insertion, while after ten years it returns to basal levels indicating the graft has been successfully integrated with the host tissue