Different angiogenic response and bone regeneration following the use of various types of collagen membranes - in vivo histomorphometric study in rabbit calvarial critical-size defects

Introduction/Objective Success of guided bone regeneration depends on the size and morphology of defect, characteristics of barrier membranes and adequate angiogenesis. The aim of the study was to reveal impact of three different collagen membranes on angiogenesis and bone production in critical-size defects.Methods Defects were created in rabbit calvarias, filled with bovine bone graft and randomly covered with one of three investigated collagen membranes (Biogide - BG, Heart - PC, Mucograft - MG) or left without a membrane for the control group (C). After two and four weeks of healing, a total of 10 animals were sacrificed for histological and histomorphometric analysis of angiogenesis, bone regeneration, and inflammatory response.Results In the early healing phase, the highest values of trabecular thickness and trabecular area were recorded with PC and BG membranes, respectively. After four weeks, significantly improved bone healing was noted in the MG group, as well as significantly pronounced inflammation. Initially, vessel density was significantly higher in the C group compared to all three membranes. After four weeks, significantly better results were observed in the MG compared to the other groups, BG compared to the rest of groups, and between PC and C groups.Conclusion The use of collagen membranes significantly affects angiogenesis, reducing it in the early and enhancing it at the later healing phase. All three tested membranes in combination with bone graft sig-nificantly improved the amount of regenerated bone. Among the investigated groups, MG favored more pronounced angiogenic, osteogenic, and inflammatory response in the observation period of four weeks.