Effects Of Parathyroid Hormone On Tooth Extraction Nest Healing In Rats With Osteoporosis

Objectives Through the establishment of osteoporosis SD rat tooth extraction model,parathyroid hormone intervention was given during the healing process,and the bone density and histomorphological changes of the newborn bone tissue in the tooth extraction fossa were observed,and the expression of tooth extraction fossa osteocalcin(OC)and insule-like growth factor-1(IGF-1)were detected.To investigate the effect of parathyroid hormone on tooth extraction socket healing in rats with osteoporosis,and to provide experimental basis for drug intervention after tooth extraction surgery in patients with osteoporosis.Methods 1 Preparation of osteoporosis model: 80 healthy female SD rats aged 12 weeks were selected and randomly divided into experimental group and control group.Rats in the experimental group were given retinoic acid at 100mg/kg once a day.Rats in the control group were given normal saline by gavage once a day.Bone density(BMD)of the proximal tibia was measured two weeks later.P<0.05,the difference was statistically significant,indicating that the bone density of rats in the experimental group was significantly decreased,and the osteoporosis model was successfully constructed.2 Preparation of tooth extraction model in rats: 40 rats with osteoporosis were anesthetized peritoneally and the left maxillary first molar was extracted.Tooth extraction rats were randomly divided into two groups on average.20 rats in the experimental group were injected subcutaneously with 20?g/kg parathyroid hormone(PTH)once a day.Twenty rats in the control group were injected with the same amount of normal saline once a day.Six rats were sacrificed in batches at 2,4 and 8 weeks after PTH injection.The alveolar bone around the tooth extraction fossa of rats was taken into a small segment of about 1cm,and soft tissue was removed for bone density detection.The specimens were then fixed,decalcified,embedded and sectioned for HE staining and immunohistochemical staining to detect the expression of OC and IGF-1.Mv-image software was used for Image collection,and Image Pro Plus 6.0 software was used to calculate the average optical density(MOD)of the immunohistochemical images.SPSS23.0 was used for statistical processing of the experimental data,and the results were presented in the form of mean standard deviation().One-way anova and t-test of two independent samples were used,and P<0.05 was considered statistically significant.Results 1 Two weeks after retinoic acid intragastric administration,the proximal tibial bone density of rats decreased,and two independent sample t tests were performed.P<0.05 was obtained,and the difference was statistically significant.The osteoporosis model was successfully prepared.2 Macroscopic observation of tooth extraction nest healing in rats showed that the experimental group was slightly better than the control group at the same time point.3 Two weeks after tooth extraction surgery,the bone density of the experimental group was higher than that of the control group,P<0.05,and the difference was statistically significant.Observation of HE staining sections showed that plenty of fibrous bone tissue appeared in the tooth extraction fossa of the experimental group,and a small number of osteoblasts were observed.There were some inflammatory cells in the control group,and few fibroid bone tissues were found.The mean optical density(MOD)of OC and IGF-1 in the experimental group was higher than that in the control group,P<0.02,and the difference was statistically significant.4 BMD of the experimental group was higher than that of the control group 4 weeks after tooth extraction surgery,P<0.05,and the difference was statistically significant.Observation of HE staining sections showed that the trabecular bone of the experimental group was thicker than that of the control group,and the trabecular bone space of the experimental group was narrower than that of the control group.The number of osteoblasts in the experimental group was slightly less than that of the control group,while the number of osteoblasts was higher than that of the control group.The mean optical density(MOD)of OC and IGF-1 in the experimental group was higher than that in the experimental group,P<0.01,and the difference was statistically significant.5 BMD of the experimental group was higher than that of the control group 8 weeks after tooth extraction surgery,P<0.05,and the difference was statistically significant.HE staining sections were observed.The trabeculae of rats in the experimental group and the control group were arranged in an orderly manner.The trabeculae of rats in the experimental group were arranged in a compact manner,while those in the control group were arranged in a loose manner.The trabecular width of the experimental group was larger than that of the control group,and the trabecular space was narrower than that of the control group.The mean optical density(MOD)of OC and IGF-1 in the experimental group was higher than that in the control group,P<0.01,and the difference was statistically significant.Conclusions 1 The SD rat model of osteoporosis was successfully prepared by retinoic acid gavage.2 Parathyroid hormone can increase the expression of tooth extraction nest OC and IGH-1 in rats with osteoporosis.3 Parathyroid hormone can promote the healing of tooth extraction litter in rats with osteoporosis.Figure 30;Table 4;Reference 147...