Angiogenesis and osteogenesis at incorporation process of onlay bone graft

Abstract

Purpose: The roles of angiogenesis and osteogenesis in autologous and allogenic bone grafts and the use of platelet-rich plasma (PRP) as a modifier were investigated. Materials and Methods: Forty rabbit mandibles received onlay grafts of fresh autologous and frozen allogeneic bone. PRP was added on the right side. After intervals of 3, 7, 14, 28, and 56 days, the animals were euthanized. Hematoxylin and eosin staining was used to measure the quantity and area of osteoblasts. Sections stained with toluidine blue showed newly formed bone area. In sections with Weigert-van Gieson staining, the number of vessels and their lumens was quantified. The quantity and area of cellular arrangements expressing CD31 and the area of vessels were obtained. Results: Quantities of osteoblasts and their areas, newly formed matrices, and vessels and their lumen areas were obtained and identified by immunomarking with CD31. In general, values for these were higher in rabbits with allogeneic bone grafts and on the sides where PRP had been added. There was a variable significance between categories and days. It was confirmed that osteogenesis was intensified when angiogenesis was consolidated. Conclusions: Angiogenesis was important for greater osteoblast differentiation and bone matrix synthesis, ensuring consolidation of onlay grafts with the receptor bed. Allogeneic grafts and PRP intensified these processes.