种植体周围骨缺损,动物造模 z-bo 2023-01-16 514

　　Implant restoration has become more and more widely used in clinical practice. However, after tooth loss due to trauma, tumor, periodontal disease and other reasons, it is often accompanied by excessive absorption of alveolar bone, resulting in insufficient bone mass, which limits the scope of application of implant dentures . Wang Rong and others used Chinese experimental miniature pigs to combine bone marrow stromal stem cells with a complex of hydroxyapatite and tricalcium phosphate to form a biomaterial complex, which was jointly applied to bone defects around implants to analyze bone defects around implants The characteristics of tissue regeneration.

　　Experimental procedure: ① Extraction of bone marrow stromal stem cells and induced differentiation culture: Aseptically extract 5-7 ml of bone marrow from the anterior superior iliac spine of miniature pigs and place them in a heparinized centrifuge tube. Apply density gradient centrifugation to suspend cells in α-MEM culture medium containing 10% fetal bovine serum, inoculate them in culture flasks, and place them in a CO2 incubator. After 24 hours, the cells adhere to the wall and when the cells are fused to 80% Perform digestion and passage, and take the second generation of cells for use. ② Identification of BMSC: Digest and count the purified BMSC of the seventh generation. Add 100μl of cell suspension to the centrifuge tube, containing 1×106 cells. Add 200μl PBS, centrifuge at 1000r/min for 5 minutes, add 200μl PBS to resuspend the cells, add FITC-labeled CD71, CD44, CD34, CD45 monoclonal antibodies, react for 1 hour at room temperature in the dark, fix with paraformaldehyde, and detect by flow cytometry . ③Combined culture of cells and scaffold materials: adjust the cell concentration to 1×106/100μl, put it in the culture medium containing hydroxyapatite-tricalcium phosphate carrier material, shake gently, culture under standard conditions, and stand by after 7 days . ④Bone defect and repair around implant: A cylindrical bone defect with a diameter of 3mm and a height of 5mm was prepared on the mesial wall of the implant bed. Each group was implanted with BMSC-HA/TCP complex, HA-TCP material (80% tricalcium phosphate and 20% hydroxyapatite), covered with Cellfoam membrane, and sutured tightly. Eight miniature pigs were randomly divided into a cell-scaffold group and a scaffold group, with 4 pigs in each group. Two animals in each group were sacrificed 1 month and 3 months after implant placement. The materials were taken separately, bone grinding slices were made, and toluidine blue stained and histological observation was performed.

　　Experimental results: 1 month after implantation in the cell-scaffold group, new bone formation was seen in the mesial bone defect area, the toluidine blue staining was bright blue, and neatly arranged osteoblasts and woven bone were seen, showing active osteogenic activity . In the 3-month group, good osseointegration was formed, mainly compact bone, and the bone was mainly composed of mature compact bone containing a large number of Haval system. It can be seen that most of the scaffold material is degraded and replaced by new bone, and blood vessels grow into the material gap, and no obvious inflammatory reaction is found. There are trabecular bone formation and Haval system structure. One month after implantation in the stent group, there was a clear gap between the stent material and the implant in the bone defect area, and the stent material gradually degraded after 3 months without new bone formation.