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Objective To investigate the effect of β-catenin on the osteogenic differentiation of human periodontal ligament stem cells (PDLSCs) under mechanical tension.Methods PDLSCs were seperately cultured in vitro from the periodontium attached at freshly extracted teeth.β-catenin-targeting agonist or inhibitor was applied to the PDLSCs to upregulate or downregulate the expression of activity of β-catenin protein.The expression of β-catenin protein and the osteogenetic related markers(ALP,BMP2,Runx 2) under the mechanical tension with different period(0,6,12,24 h) were assessed with Western blot in the PDLSCs irritated with agonist or inhibitor.Results Compared with the PDLSCs without mechanical tension,the expression of osteogenesis related marker proteins,ALP and Runx 2,in PDLSCs were enhanced under the circular mechanial tensile stress (P ＜ 0.05).In the PDLSCs irritated with WAY-262611,the β-catenin-targeting agonist,the expression of osteogenetic related markers ALP in the PDLSCs was improved during the first 12 h period of mechnical tensile load,which was significantly higher than that in the DMSO group.Conclusion Wnt/β-catenin signaling pathway plays an important role in the early osteogenesis differentiation of PDLSCs under cyclic tension.The β-catenin promotes osteogenic differentiation of PDLSCs under mechanical tension.
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Objective To explore the effect of Notch1 signal pathway on the osteogenic differentiation in human periodontal ligament stem cells(PDLSCs) under dynamic strain.Methods PDLSCs were separated from freshly extracted teeth then identified and prolifed.Notch1 signal pathway was regulated by chemicals.Dynamic strains were applied to PDLSCs with the tension plus system.Then Notch1 signal pathway key factor Notch intracellular domain(NICD),osteoblastic related indexes alkaline phosphatase(ALP) and bone morphogenetic proteins 2 (BMP2) were detected by western blot expression.The deformation rate of stress parameters was 0 to 12%,and the frequency was 0.1 Hz.The loading time was 0 h,6 h,12 h and 24 h.Results As Notch1 signal pathway was activated,the expression of osteogenic markers ALP and BMP2 both reduced (P<0.05).On the contrary, the expression of osteogenic markers ALP and BMP2 both increased obviously (P<0.05) as Notch1 signal pathway was inhibited.Conclusion The activated Notch1 signal pathway will inhibit osteogenic differentiation of PDLSCs under dynamic tensile.
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Objective To up-regulate the expression of Glil gene in periodontal ligament stem cells ( PDLSCs) and to explore the effect of Glil gene on PDLSCs proliferation and osteogenesis differentiation by establishing Glil gene adenovirus vectors. Methods Subcloned Glil to viral backbone vector Adtrack-CMV and transfered the established vector to 293T cells, which was to acquire the virus particles. Trans-fected aim cells,namely PDLSCs,with these virus. Detected its effect on PDLSCs proliferation with CCK-8 assay, and detected the expression of Glil and the bone-related markers ALP and Runx2 through Western blot. Results An adenovirus vector, which were over expressed Glil gene, was successfully constructed and transfected to PDLSCs. Compared with the empty vector group and normal group, the over expressed one had a much slower proliferation rate in CCK-8 assay (P=0. 003). Western blot showed that ALP and Runx2 can be overexpressing os-teogenic differentiated after PDLSCs successfully transfected with the Glil gene. Conclusion Over expressing Glil gene would lead to a much slower proliferation rate in the PDLSCs and an increase of the bone-related markers. It is concluded that Glil can enhance the osteogenic dif-ferentiation capacity in PDLSCs.
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Objective To investigate the shape and F-actin of human periodontal ligament fibroblasts(HPDLF) under different tension stress in vitro so as to learn the stress-biological effects of HPDLF. Methods HPDLF were cultivated for 6 passages and observed morphologically and identified by immunocytochemistry to be positive anti-vimentin and negative anti-keratin. HPDLF were divided into four groups: control (without tension stress), static tension stress (5 kPa), dynamic tension stress group 1 (5 to 0 to 5 kPa at the frequency of 3/min) and dynamic tension stress group 2 (5 to 2.5 to 5 kPa at the frequency of 3/min). The cells of each group were observed at the different time points of 16, 24, 32 h. The projection areas and shapes of cells as well as the structure of F-actin were examined by laser scanning confocal microscope and immunity fluorescence technique. The relationship among tension stress, time, shape and the structure of F-actin of HPDLF was analysed. Results In the dynamic tension stress group 1 and 2, the shape and the arrangement of F-actin of some HPDLF underwent regular changes at 16, 24 h, but the changes appeared to be obvious at 32 h. In the static tension stress group, it was found the increase of interspace of HPDLF, but no obvious changes in the structure of F-actin. Conclusion Different tension stress patterns had different effects on the shape and F-actin of HPDLF. Especially in the dynamic tension stress group 2, it showed direct ratio between the cell projection areas, the average fluorescence density and different loading time.
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Objective To study the effect of CEREC CAD/CAM ceramic inlay on repair of wedge-shaped defects of teeth and test its anti-fracture properties. Methods Extracted teeth were divided into control group ( n = 16) and experimental group ( n = 16) ,and prepared into imitating teeth with wedge-shaped defects. Teeth in experimental and control groups were repaired with CEREC CAD/CAM ceramic inlay and light-cured composite resin,respectively. Anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM was assayed on a universal testing device with its maximal loading recorded. The anti-fracture strength was compared between the 2 groups. Results The anti-fracture strength of teeth with wedge-shaped defects repaired with CEREC CAD/CAM ceramic inlay was significantly higher in experimental group than in control group ( 3. 56 ? 0. 27 vs 2. 43 ? 0. 15,P
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Objective To test the fracture loading of extracted cracked teeth with CEREC CAD/CAM ceramic inlays/onlays. Methods All the extracted teeth were divided into two groups (A: control group; B: test group; n=15 teeth in each group). All the teeth were prepared into those imitating cracked teeth. Those teeth in group B were strengthened with CEREC CAD/CAM ceramic inlays/onlays. All teeth were thermocycled and mounted for testing and then were loaded until fracture. Results The force of anti-fracture of extracted teeth imitating cracked teeth with CEREC CAD/CAM ceramic inlays/onlays (group B) was obviously higher than that of the teeth without CEREC CAD/CAM ceramic inlays/onlays (group A). Conclusion CEREC CAD/CAM ceramic inlays/onlays can effectively prevent the crack of teeth in clinical practice.
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Objective:To study the biting force of upper premolar and molar in the patients with unilateral cleft lip and palate(UCLP).Method:25 health people and 22 cases (13 male and 9 female with pemanent teeth) of UCLP without tempromandibular joint dysfuction were selected in the subject.Their biting force of upper premolar and molar in intercaspid position was tested by MBF 1 device,meanwhile,their mastictory perfomance and contact area of upper premolar and molar were checked.All of the results were managed by computer with SPSS 7.5 statistics software.Results:①Biting force of upper premolar and molar of male was higher than that of female in health people,but there was no sexual difference in UCLP.② Biting force in the group of UCLP was lower than that in the control (P