ABSTRACT
Objective:To investigate the protective effect and mechanism of low-intensity pulsed ultrasound on human periodontal ligament stem cells (hPDLSCs) injured by high glucose.Methods:hPDLSCs were cultured in vitro and randomly divided into normal control group, high glucose model group and three low intensity pulsed ultrasound groups (30, 60, 90 mW/cm 2). Cells in the high glucose model group and three low intensity pulsed ultrasound groups were treated with high glucose medium (glucose 40 mmol/L) for 48 h to establish high glucose model. Cells in the normal control group were treated with normal medium (glucose 11 mmol/L). After modeling, three low intensity pulsed ultrasound groups were treated with low-frequency pulse for 20 min each day for 7 days at a dose of 30, 60 and 90 mW/cm 2 respectively. After 7 days, the proliferation ability of each group was determined by MTT assay. The changes of cell cycle and apoptosis were detected by flow cytometry. The level of Caspase-3, Caspase-6, and Caspase-9 was detected by colorimetry. The levels of Wnt1, Wnt10b and β-catenin genes and proteins were detected by reverse transcription PCR and Western Blot respectively. Results:Compared with the hPDLSCs in the normal control group, the hPDLSCs in the high glucose model group have the following changes except for the cell cycles (all P>0.05), i.e. the activity of the cells was decreased and the apoptosis was increased (all P<0.05), the activities of Caspase-3, Caspase-6, and Caspase-9 were increased (all P<0.05), and the expressions of Wnt1, Wnt10b and β-catenin genes and proteins were decreased (all P<0.05). Compared with the hPDLSCs in the high glucose model group, the hPDLSCs in low-intensity pulsed ultrasound groups have the following changes expect for the cell cycles (all P>0.05), i.e. cell viabilities were increased (all P<0.05), proliferation abilities were increased (all P<0.05), apoptosis rates were decreased (all P<0.05), the activities of Caspase-3, Caspase-6, Caspase-9 were decreased (all P<0.05), and the expressions of Wnt1, Wnt10b and β-catenin genes and proteins were up-regulated ( P<0.05). Among the three low-intensity pulsed ultrasound groups, when the ultrasonic intensity is 90 mW/cm 2, the above-mentioned index changes most obviously (all P<0.05). Conclusions:Low-intensity pulsed ultrasound can significantly alleviate the hPDLSCs damage induced by high glucose, which may be achieved by reducing the activities of Caspase-3, Caspase-6 and Caspase-9, and up-regulating the expression of Wnt1, Wnt10b and β-catenin.
ABSTRACT
BACKGROUND:Mini-implants are widely applied in the clinical treatment of orthodontics and orthognathics, because they can provide absolute skeletal anchorage. However, the relatively high failure rates have always been their major drawback, and how to improve the success rates of mini-implants becomes the main research direction in recent years. OBJECTIVE:To summarize the factors influencing the stability of mini-implants. METHODS:A computer-based search of Wanfang, VIP and PubMed databases was performed using the keywords of “mini-implants, stability, success rate, osseointegration” in Chinese and English. RESULTS AND CONCLUSION:Mibni-implants are an effective means of anchorage control. In clinics, the factors such as implant design, health status of patients, implantation methods and regions, loading patterns and maintenance after implantation wil al have an influence on the stability and success rates of mini-implants. To improve the success rate of the mini-implants, the selection of appropriate implant area is necessary in clinical applications, for example, thicker cortical bone and higher mini-implants are recommended clinicaly; using reasonable and loading implants, studies have shown that non-scored mini-implants is beneficial to reduce the dropout rate of mini-implants during early orthodontic loading; maintenance during healing periods after implantation is emphasized, and currently, stress loading on the mini-implants is preferred immediately after implantation or earlier, which can have a better success rate.
ABSTRACT
BACKGROUND:Basic fibroblast growth factor is a pluripotent cytokine that can promote the proliferation of mesodermal and neuroectodermal cells. OBJECTIVE:To observe the effect of basic fibroblast growth factor in human periodontal ligament cells cultured in vitro. METHODS:Human periodontal ligament cells at passage 5 were inoculated into the 96-wel plates at the density of 1×108/L, and were randomly divided into four groups. The cells were cultured inα-MEM containing 15%fetal bovine serum and 0, 1, 10, 100μg/L basic fibroblast growth factor, respectively. At 1, 3, 5, 7 days of the culture, the cellproliferation was determined, and the activity of alkaline phosphates was detected at 1 and 7 days. RESULTS AND CONCLUSION:There were significant differences in the proliferation of human periodontal ligament cells among the four groups (F=6.586, P=0.024). As the increase of the basic fibroblast growth factor concentrations, the absorbance value was gradual y increased and reached the peak in 100μg/L basic fibroblast growth factor group (P<0.05). The alkaline phosphatase activity in basic fibroblast growth factor groups was lower than that of the control group (P=0.000), the higher the concentration was, the lower activity was (P<0.05). Results show that basic fibroblast growth factor can promote the proliferation of human periodontal ligament cells and inhibit the activity of alkaline phosphatase, and the effect is concentration-dependent.