EFFECTIVENESS OF COMBINATION OF VITAMIN D WITH CHITOSAN HYDROXYAPATITE VERSUS CHITOSAN HYDROXYAPATITE ON BONE REGENERATION IN CRITICAL SIZE DEFECT (AN EXPERIMENTAL STUDY IN RABBITS)

Background: It is challenging for bone to heal in a critical-size lesion. Tissue engineering produces better results, but it necessitates the use of costly additives such as stem cells and bone morphogenic proteins. Vitamin D3 plays an important role in bone turnover and mineralization by means of osteoblast and osteoclast activation. Chitosan is extensively employed in bone tissue regeneration, drug delivery, wound healing and osteoconductive properpties. The use of chitosan in conjunction with other bio-active materials, such as hydroxyapatite, has demonstrated efficacy in promoting bone repair. Hydroxyapatite is a synthetic, ceramic substance that has demonstrated efficacy in the production of new bone. Injectable hydrogel has shown effectiveness in encapsulating a range of biological components, including medicines and cells for tissue engineering. Aim of the study: Evaluate and compare the amount of bone formation using chitosan hydroxyapatite composite hydrogel versus chitosan hydroxyapatite vitamin D hydrogel.Materials and Methods: 36 Male rabbits were used in the study. A critical size osseous defect was induced in the tibia of each animal. The sample was divided into 3 groups. The first group was left empty as a negative control, the second group was filled with chitosan hydroxyapatite composite hydrogel and the third group was filled with vitamin D3 chitosan hydroxyapatite hydrogel. Scarification was done after 4 and 6 weeks.Results: This study finds that vitamin D3 accelerates bone formation and promotes bone maturation.Conclusion: Applying vitamin D3 (calcitriol) locally speeded up the production of new bone as shown by histological and histomorphmetric analysis