Implantation of beta-tricalcium phosphate combined with osteoblast-specific peptides for alveolar bone preservation in extraction sockets / 中国组织工程研究

ABSTRACT

BACKGROUND: Previous findings show that osteoblast-specific peptides can promote the repair and regeneration of skull defects in rabbits, and β-tricalcium phosphate (β-TCP) is used as a scaffold to carry osteoblast-specific polypeptides. Both of them not only complement each other, but also fully exert dual effects of osteoinduction and bone conduction. OBJECTIVE: To investigate the effect of osteoblast-specific peptide on the preservation of the anterior tooth extraction site in rabbits, and to study the effect on the alveolar bone remodeling. METHODS: Twenty-seven New Zealand white rabbits were randomly divided into three groups (n=9 per group), and the right mandibular incisors were removed to establish the animal models of tooth extraction. β-TCP/osteoblast-specific peptide compounds were implanted in the experimental group, and pure β-TCP meal was implanted into the material group. The blank control group had no implantation. Three rabbits from each group were scarified at 4, 8 and 12 postoperative weeks, and tissue samples were prepared for gross observation, histomorphology measurements, and radiographic measurements of extraction socket healing. RESULTS AND CONCLUSION: (1) Imaging results showed that the relative length of residual alveolar bone after modeling was ranked as follows the experimental group > the material group > the blank control group, and the difference was statistically significant among groups (P < 0.05). Cone-beam CT findings in the three groups changed as time went on. At 4 and 8 postoperative weeks, the implanted materials in the experimental and material groups gradually degraded; the bone mass in the experimental group was significantly higher than that in the material and blank control groups. At 12 postoperative weeks, the experimental group had basically completed the reconstruction of tooth socket, but there were still some bone defects in the material and blank control groups. (2) Histomorphological findings showed that at 4 postoperative weeks, the experimental group exhibited obvious bone deposition lines, and the bone trabecula was widened; in the material and blank control groups, the new bone was less. At 8 postoperative weeks, a small amount of undegraded scaffold was found in the experimental group, with mature lamellar bone, the amount of new bone tissues in the material group increased and osteoblasts were obviously detected in the blank control group. At 12 postoperative weeks, the bone remodeling in the extraction socket of the experimental group was basically completed; in the material group, there were still a small amount of scaffold materials and dense plate-like new bone; and in the blank control group, the new bone tended to be mature, and there was obvious lamellar structure. To conclude, osteoblast-specific peptides can effectively preserve the length of the residual alveolar bone after tooth extraction, promote the formation of new bone, and have the function of preserving the tooth extraction site.