Histological evaluation of the osteoinduction capability of demineralized human dentine implanted in the muscles of rats: A chronologic study

Abstract
Background: Nowadays different materials are being used in alveolar bone reconstruction surgeries. Dentin is one of the biomaterials has drawn attention in recent years, but the results of studies are inconsistent.Aim: The aim of this study was to investigate osteoinduction capability of demineralized human derived-dentin particles implanted into muscular tissue.Material and methods: The present experimental study was carried out on adult Rats (8 weeks old ,200-250 gram). Demineralized human dentin (DHD) was implanted (100mg) in latissimus dorsi muscle under the deep anesthesia. At the end of one, second and fourth months, tissue samples were removed and stained with H&E.Result: At the end first month, the particles were enclosed with connective tissue. Multinucleated giant osteoclast attached to the DHD particle, capillaries and differentiating cells in vicinity of particles less than 250 µm were found. Fibroblasts and differentiating cells around the scalloped borders of the large dentin particles (> 850µm) were found. At the end of second month differentiating cells from deeper layer of collagenous capsule, young osteoblast and osteoid deposition adjacent and between the particles (250 µm) were seen. At the end of fourth month capillaries, differentiating cells, osteoid formation and osteoblasts were also found in vicinity of the ruffled margin of the large particles. Young osteoblasts and fibroblasts were observed in dentin niches. Quantification of new bone formation showed that meaningful difference between the 120 days (45±3 µm2 ), 60 days (23±5 µm2 ) and 30 days (0) (p < 0.05).Conclusion: our results suggest that demineralized human dentin particles less than 250 µm induce osteoinduction two month after implantation. Larger particles (>850µm) showed limited osteoinduction only in ruffled margins and dentin artifactal niches after four months. Additionally bone formation proceeded at higher rate after 120 days.