疾病动物模型,Ⅱ度根分叉缺损模型 z-bio 2021-10-27 482

　　A model of piglet's Ⅱ degree root bifurcation defect was established by surgery.

　　1. Experimental method: 4 13-month-old Chinese experimental miniature pigs, male, weighing 28.5-31.5k. After conventional anesthesia, the miniature pig is fixed on the animal's operating table. After disinfection and draping, a tooth stretches back and forth around the surgical tooth. The second anterior teeth of the upper and lower jaws are located in the center. A vertical incision is made between the buccal gingival papilla and the distal end of the buccal gingival papilla of the first molar, and a gum separator is used to open the gingival flap to completely expose the buccal alveolar bone of the surgical tooth. Using a bone knife, remove the buccal alveolar bone of the experimental tooth to expose the bifurcation area, and then remove the alveolar bone at the bifurcation area 5 mm in the direction of the bite and buccal tongue to remove the alveolar bone in the bifurcation area twice . bone. Create a defect model, smooth the root surface, and rinse with 3% hydrogen peroxide and saline to restore the gums. Gently press the buccal side with a saline cotton ball to make the mucoperiosteal flap closely contact the bone surface. Intermittently suture the gingival flap with .4 sutures. The criterion for successful modeling is the presence of a bone defect in the bifurcation zone, but this has not yet been communicated. Periodontal probes can be used to enter the bifurcation zone from horizontal to different depths. Remove stitches one week after modeling and keep them for eight weeks. After successful modeling, the 3rd and 4th premolars of the upper and lower jaws of each minipig were used as experimental teeth. A total of 16 experimental teeth from 4 miniature pigs were randomly divided into two groups. Model group: only 2 root scoring fork defect models were established without intervention; control group: after modeling, once a week, 50 mg/h each time, 2.2 mg simvastatin gel each time for artificial root furcation defects , After injection, lightly press the injected tissue, and cover the skin flap tightly to the bone surface. After 8 weeks of observation, the animals in each group were sacrificed. After general observation, teeth and periodontal tissue masses were prepared on the hard tissue centered on each experimental tooth, and fixed with a 10% morphological fraction solution for histological morphological observation.

　　2. Experimental results. Eight weeks after surgery, these animals are healthy. No obvious soft dirt was found on the experimental teeth. There is no congestion or swelling of the gums, bleeding or significant tooth loosening during probing. In the control group, there was no obvious soft scale on the experimental teeth, some gums were slightly congested and swollen, there was no bleeding during the exploration, and there was no obvious loosening of the teeth. After eight weeks of modeling, the soft tissues and mucous membranes of all experimental animals were removed to expose the jaws. It can be seen that the root bifurcation area of the model group is empty, and there is almost no growth of new bone tissue. Many blood vessels and fibrous connective tissue can be seen. The new bone in the control group was basically overgrown. There is no clear boundary between the defect area and the surrounding bone tissue. There was no significant difference in defect height between the two groups of animals before the experiment. The height of the new alveolar bone in the model group was lower than that in the control group (P\u003c0.05). Pathological examination showed that the new alveolar bone of the experimental teeth in the control group was almost filled with the root bifurcation area, showing the trabecular meshwork and mature Haval system, while the model group showed clear new bone, none. The cell count results showed that the control group showed more mature fibrous tissue and vascular proliferation. The number of osteoblasts was higher than that of the model group (P\u003c0.05), and the number of bone cells was also higher than that of the model group (P\u003c0.05).