Histological Evaluation Effect of Local Application of Vitamin D3 on Bone Formation in Rabbits
Bone is a highly specialized form of connective tissue that is nature’s provision for an internal support system in all higher vertebrates, its formation and regeneration is still desiring research zone and using the tissue engineering approach that depends on the various types of interactions between the cells, scaffolds, and growth factors. Vit.D3 is a fat-soluble hormone, calcitriol is active form of Vit.D3, can affect osteoblast growth and differentiation stimulating bone formation and mineralization, no consensus exists regarding the applicable benefit of local application in bone defect healing which still controversy. Twenty-four adult male New Zealand rabbits weighting an average of (1.5–2 kg) used in this study. One intra bony holes created in both tibias (right tibiae for experimental groups and left for control group) of each animal which will be divided as follows: Group I(C): Bone defect left to heal spontaneously as control. Group II (Vit.D3): Bone defect filled with Vit.D3. Animal scarification was done for the healing durations (7 and 21days). Routine processing and sectioning technique was performed for histological evaluation. The histological finding in the bone defect area filled with Vit.D3 shows fine separated bone spicules rimmed by osteoblast and some embedded osteocytes. VIT.D3 group after 21 days shows defect area with many bone trabeculae surround bone marrow, and primary harversian canals start to organized. At 7 day duration of healing period histomorphometrical study shows highly significant difference between (C) and (Vit.D3) for all measured parameters. Regarding 21days duration high significant differences were estimated in all bone parameters in between groups, except trabecular number there was no significant difference between C and Vit.D3 experimental groups. Conclusion: local Vit.D3 application may accelerate new bone formation.