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.

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

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.

Objective To explore the potential influence of a high-fat meal on systemic inflammation and fibrinolytic dysfunction in normocholesterolemic patients with essential hypertension(EH).Methods Plasma concentrations of lipids profiles,high-sensitivity C-reactive protein(hsCRP),plasminogen activator inhibitor type 1(PAI-1)and tissue plasminogen activator(t-PA)antigens in fasting state(F)and at 4 hours after a single high-fat meal(P)were measured in 54 EH patients and 30 healthy controls(Con).Results Postprandial triglyceride concentrations increased significantly in both hypertensive patients and healthy controls(P

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

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.

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.

OBJECTIVE: To set up a natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats in order to offer an appropriate carrier for the study on mechanism of intervertebral disc degeneration. METHODS: The method of enzyme digestion combined with natural subculture was used to set up the in vitro natural degeneration model of chondrocytes derived from the endplate of intervertebral disc of rats. The morphological appearances and microstructures of the chondrocytes of different generations were observed. The expression of collagen II in chondrocytes was detected by immunocytochemical method. RESULTS: The chondrocytes derived from the endplate of intervertebral disc expressed collagen II. After 13 days of culture, the chondrocytes of generation III showed that the ability of cell division descended, the nucleoli became unclear, the cells deformed obviously, fusiform shape with weak optical activity appeared, and the intercellular space was enlarged. There were vacuoles and lipid droplets in cytoplasm. The synthesis of collagen II, as well as the cell proliferation rate, descended notably. All results showed the natural degeneration process of the chondrocytes. CONCLUSION: The in vitro natural degeneration model of chondrocytes derived from endplate of intervertebral discs of rats was successfully established. This can offer the cytological basis for study on the mechanism of intervertebral disc degeneration.

Objective To analyze the feature and cause of stumps of amputees after Wenchuan earthquake,and study the effects of rehabilitation treatment for stumps.Methods Fifty-two cases with stump limbs post-amputation were evaluated,including stump skin status,stump shape,stump length,stump swelling,range of motion (ROM)of joint and strength of stump,and were treated with physical therapy,stump moulding and kinesiotherapy.Results The incidences of stump ulcer,stump swelling,conical stump,short stump and limitation of ROM of joint in all 52 cases were 76%,73%,34%,40%and 42%respectively.After rehabilitation treatment stump ulcers healed,stump swelling eliminated;stump shape,ROM of joint and muscle strength improved obviously.All poor stumps could be fit with the prosthetic limb and get good function.Conclusion The incidences of poor stump limb post·amputation after earthquake were high.Rehabilitation treatment can improve the stump condition.Early comprehensive rehabilitative intervention after amputation is important for fitting the prosthetic limb tO the stump.

Objective To evaluate the effect of prosthetic rehabilitation and analyze the exercise training program with myoelectric signal for upper limb stumps.Methods Twenty canes with 22 upper limb stumps were treated with exercise for strength training,muscle contraction and control training and the complication of stump were managed.The myoelectrlc signal of upper limb stumps were detected and the stumps were trained with electronic biofeedback software system,including basic signal of biofeedback training and visual biofeedback training.Then the myoelectric prostheses were assembled.Results After prosthetic rehabilitation and myoelectfic signal training,there Wan no significant atrophy of muscle of stumps,muscle strength and range of motion of these twenty limb stumps increased.The amputees could control muscle contraction and grasp,pinch,wrist rotation,elbow extension or flexion consciously.Twenty myoelectrie prostheses were assembled.Conclusion The prosthetic rehabilitation and myoelectric signal training of limb stump is important for assembling myoelectric prosthesis.