Background: The repair of bone defects remains a major clinical challenge in dentistry. Bone is a highly vascularized tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. The health promotive , preventive, and curative properties of herbs were recognized by the ancient and the present pharmacist and physicians to form the theoretical foundations in Medicine. Objective: Immunohistochemistry of osteocalcin and histological study to prove that symphytum officinale oil when applied locally on generated bone defect healing in rat tibia, it was very effectiveness. Patients and Methods: 0ur study fourty male rats , weighting (250-350) grams ,aged (5 7)months ,was performed under same food and drinking utilization with same temperature conditions. The surgical operation of tibiae bone to medial side of rat were subjected, the bone defect were left to cure normally in control group , whilst experimental group was applied1μm symphytum officimale oil locally as a treatment. Every rat was killed at 7 or 14 days after surgery (ten rats for each period). Results: When we applied the symphytum officinale oil locally on bone defect increased cell count in each of osteocyte ,osteoclast and osteoblast and deposed of early osteoid tissue . stromal cells evaluated by Immunohistochemical study of osteocalcin which reported to increase in significant difference in symphytum officinale group when compared to control group. Conclusion: Low application of symphytum officinale oil in our study expressed to be a good and effective treatment in injuries of bone; these evidence in our data are pledging for a possible clinical management in future. Keywords: Bone defect, symphytum officinale oil, osteocalcin.
