Objectives: The aim of the study was to evaluate the bone regenerative process after AG or HG used as graft to correct intraoral defects in human.

Methods: Autologous bone from calvaria and heterologous bone of equine origin were used to recreate adequate bone volumes in the posterior maxilla before implant therapy. Specimens were withdrawn from regenerated sites four months after grafting (T1) and compared to each other by light microscope and SEM. Samples were processed in order to investigate BSP, iNOS, MMP9, and VEGF expression by immunohistochemical analysis.

Results: Microscope observation showed that, after four months, remodeling of the graft was quite completed in sites which received autologous extraoral graft, while differences among host tissue and the bone graft were more evident in sites treated with heterologous graft. Immunohistochemical analyses showed that BSP, MMP9, and VEGF expression was higher in samples from sites treated with autologous bone graft from calvaria. iNOS levels were higher in samples of heterologous graft.

Conclusions: The capability of host tissue to initiate graft revascularization and remodeling was investigated by analyzing changes in expression of molecules involved in this early phases, like BSP, MMP9, and VEGF. Their expression increase after four months from the grafting, the moment of implants insertion, for both investigated graft, but they resulted significantly more expressed in calvaria bone grafts, indicating a more rapid angiogenic and regenerative response. The minor amount of iNOS found in samples from calvaria bone grafts indicated that inflammatory phenomena has almost all disappeared after four months.

Conflict of interest: None declared.