Expression of CD44, CD29 and osteocalcin differentiation factors in the alveolar bone during past fixation of a free gingival graft

Abstract

Aim: To study the localization of stem stromal cells on the surface of a free gingival graft. Material and methods: We studied the immunolocalization of stem cell markers (CD29, CD44 and osteocalcin) the mucosa plate and bone tissue of the lower jaw of outbred miniature pigs with bone fixation of a free gingival graft. Results: In the third month after the operation, a new bone tissue is formed in the contact area, characterized by formed bone plates, osteons, and a system of Havers and Volkman channels. When studying the immunolocalization of CD29, CD44, and osteocalcin, we detected a heterogeneous distribution. CD29and CD44-immunopositive cells prevail at the border of the newly formed bone and its own gingival plate, as well as in the cavity of the Havers canals. Osteocalcin-positive cells are localized mainly in the layer of common plates, on the surface of the bone plates of osteons surrounding the Havers channel and in its cavity, which are in close proximity to the graft. Conclusion: Bone fixation of SDT remodels the alveolar bone, showing signs of a reparative process. The presence of expression of CD29 and CD44 in bone tissue indicates the activation of mesenchymal cambial cells, which differentiate into osteocalcin-containing osteoblasts. The inducing role of a free gingival graft in the formation of a new bone is determined by the ability of its cells to synthesize trophic factors stimulating the proliferation and differentiation of MSC and vascular growth. Thus, the model on miniature pigs is a useful tool for studying this process.