The histopathological evaluation of the effect of combined graft and platelet rich fibrin implementation on healing of bone defects

The purpose of this study was to evaluate and compare the effects of Platelet Rich Fibrin (PRF) usage combined with graft and as a membrane on healing of bone defects. For that purpose, four defects with 9mm diameter were constituted in each parietal bone of 14 White Vienna rabbits. First defect was untreated as control (Group A), Hydroxyapatite/tricalcium phosphate graft (HA/TCP) and collagen membrane were used in second defect (Group B), HA/TCP and PRF membrane were used in third defect (Group C) and combined HA/TCP PRF graft and collagen membrane were used in fourth defect (Group D). All samples were sacrificed at post-operative 4th week (n:7) and 8th week (n:7) periods and all skulls were amputated. Preparates were obtained from each group and then new bone formation, mature and immature bone formation, presence of bone marrow, the ratio of defect closure, inflammation, vascular proliferation, new connective tissue formation, histiocit cell groups were evaluated histopathologically. It is found that there is a statistically significant difference between four groups in new bone generation for 4 and 8 weekly periods (p:0,042 ve p:0,015). At both 4 and 8 weekly periods, new bone generation is the highest in Group C, and Group D, Group B and Group A come after sequentially. Other than new bone generation, a statistically significant difference is found between groups in other evaluated parameters such as inflammation, vascular proliferation, connective tissue regeneration, histioid cell community, bone marrow formation at 4 th week and connective tissue regeneration, histioid cell community, mature bone generation and bone marrow formation at 8 th week. As a conclusion, higher new bone formation was determined in group which PRF membrane and HA/TCP graft were used when compared with control group and the group which HA/TCP graft was covered with collagen membrane both at 4th and 8th weeks. It is shown that TZF which includes high amount of growth factor and cytokine is a successful alternative to kollagen membrane. Key Words: Platellet Rich Fibrin , Collagen membrane, Bone defect healing, New bone generation