Histopathological and immunohistochemical examination of rosmarinic acid and hyaluronic acid applications with the use of alloplastic bone graft material on bone defects created in the calvarial bone of rats

Aim: We aimed to stimulate osteogenesis with graft materials and to evaluate the effects and healing properties of osteoconductive especially hyaluronic acid (HA) and rosmarinic acid (RA) on osteogenesis histopathologically and immunohistochemically. Material and methods: 48 Wistar Albino rats were divided into defect, defect + HA, defect + RA, defect + graft, defect + graft + HA, defect + graft + RA groups. An 8 mm diameter defect was opened in the rat calvarium. HA and RA were applied to separate groups after alloplastic graft application. Animals were sacrificed at the end of 6 weeks. Biochemistry, histopathology and immunohistochemical statistics and evaluation were done. Results: In biochemical findings, ALP values increased at the end of 6 weeks in the defect + graft, graft + HA, graft + RA group compared to the defect group. Calcium and creatine kinase activity affecting bone formation were found to be lower in the defect group compared to defect + graft, graft + HA and graft + RA. TAS value was significantly higher in defect + graft + HA and defect + graft + RA groups compared to defect and defect + HA groups. OSI was found to be significantly lower in defect + graft + HA and defect + graft + RA groups compared to the defect group. Histopathologically, scar tissue, increase in mononuclear cell infiltration, degenerative collagen fibers and necrosis were observed in the defect group. In the defect + HA and defect + RA groups, small bone trabeculae and bone matrix areas where osteoblast cells were seen were observed. Dense collagen and fiber increase, small bone trabeculae and osteoblast cells were observed in the defect + graft group. It was observed that in the defect + graft + HA and defect + graft + RA groups, especially the bone trabeculae within the graft area began to form, osteoblasts became prominent in some areas and osteocyte lacunae were formed. BMP (bone morphogenic protein) -2 and BMP-4 expressions were densely seen in defect + graft + HA and defect + graft + RA groups. Conclusion: We think that the use of HA and RA after grafting will increase the efficiency of the treatment and contribute to the formation of new bone as a complementary application in the treatment of intraosseous defects.