The aim of this study was to analyze histologic and immunohistochemical modifications taking place in maxillary sites reconstructed by iliac crest bone grafts, 4 months (T 1) and 10 years (T 2) after grafting, in comparison to native iliac crest bone (T 0).By light microscopy, T 1 samples showed well-organized osteoblasts and extracellular matrix (ECM), and surrounding areas of connective tissue where a discrete number of blood vessels can be distinguished. Samples obtained from reconstructed areas after a long period of follow-up (T 2) were characterized by uniform mineralized ECM with cavities containing osteocytes, whereas T0 samples disclosed both mineralized matrix and bone marrow. Matrix metalloproteinase 2 (MMP-2), vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), and bone sialoprotein (BSP) expressions were investigated by immunohistochemical analysis. Both MMP-2 and VEGF showed significantly increased expression in T1, with respect to T0, and lowered in T 2. Otherwise, BSP expression, which was elevated in native iliac crest bone (T 0), was deeply decreased in T 1 and T 2 samples. Moreover, changes in iNOS expression and in apoptotic cell nuclei percentages (TUNEL analysis) seemed to have a similar trend, increasing in T 1 and lowering in T 2.After a period of 4 months, iliac crest bone graft-reconstructed sites show mineralizing nuclei not strongly represented, as suggested by BSP lower expression, whereas new blood vessel proliferation and active remodeling phenomena are developing. After a long period from the grafting (T 2), BSP expression decreases along with MMP-2, VEGF, and iNOS, suggesting the presence of only weak arrangement phenomena of the graft.
- Bone sialoprotein
- Iliac crest bone graft
- Inducible nitric oxide synthase
- Matrix metalloproteinase 2
- Vascular endothelial growth factor
ASJC Scopus subject areas