[Abstract] Objective: To investigate the effects of histone demethylase Jumonji D3 (Jmjd3) on the senescence of rat BMSCs from different embryonic origins. Methods: BMSCs were extracted from mandibular (M) and tibia (T) of rats and cultured for the following experiments. The characteristics of cell senescence were detected byβ-gal staining, and osteogenic differentiation were detected by alizarin red staining. The expression of Jmjd3 and senescence related factors, P16 and P21, were detected in M and T group by qRT-PCR and Western Blot. Then, shJmjd3 Lentivirus was constructed and transfected into T-BMSCs to knock down Jmjd3 expression. A critical-sized bone defect model was established in the rat jaw region and shJmjd3-modified BMSCs were transplanted into the defect area. The bone healing region by BMSCs transplantation was detected by Micro-CT and Masson staining. Results: SA-β-gal staining revealed that the number of senescent cells in T-BMSCs was significantly higher than that of M-BMSCs, as well as the expression of Jmjd3 and senescence related factors. T-BMSCs transfected with shJmjd3 resulted in decreased SA-β-gal positive staining cells and declined expression of Jmjd3 and senescence factors. Compared with GFP T-BMSCs, rats transplanted with shJmjd3 T-BMSCs exhibited the increased mean bone density and bone volume fraction by Micro-CT, as well as elevated trabecular bone structure by Masson staining. Conclusions: M-BMSCs exhibited lower senescence characteristics than that of T-BMSCs, which have a higher Jmjd3 expression. Inhibition of Jmjd3 in BMSCs can enhance the anti-senescence ability of cells and promote bone repair in vivo.

Objective：To investigate the effect of SFRP2 on osteogenic differentiation potential of adipose-derived stem cells (ADSC). Methods：Lentiviral SFRP2 shRNA was used to silence the expression of SFRP2. Retroviral HA-SFRP2 was used to over-express the SFRP2 in ADSC; real-time RT-PCR and Western Blot were used to detect the expression of SFRP2. Alkaline phosphatase activity, alizarin red staining, mineralization and real-time RT-PCR were used to detect the osteogenic differentiation of adipose-derived stem cells. Results：Real-time RT-PCR and Western Blot results showed that SFRP2sh effectively reduced the expression of SFRP2 in ADSC. Depletion of SFRP2 reduced alkaline phosphatase, mineralization and bone sialoprotein (BSP), Osterix (Osx) and runt-related transcription factor-2 (RUNX2) in ADSC. Real-time RT-PCR and Western Blot showed that HA-SFRP2 can be effectively overexpressed in ADSC. The results of alkaline phosphatase, alizarin red and calcium qualitative analysis results showed that the over expressed SFRP2 in ADSC could significantly promote the osteogenic differentiation of ADSC. Real-time RT-PCR results showed that the SFRP2 significantly promoted the expression of BSP. Conclusions：SFRP2 can promote osteogenic differentiation of adipose stem cells and prove that SFRP2 is the key gene for osteogenic differentiation of ADSC.

Objective： To investigate the effect of recombined human parathyroid hormone rhPTH (1-34) on the proliferation and odonto/osteogenic differentiation of human stem cells from apical papilla (SCAPs) in vitro. Methods： Primary SCAPs were isolated by the method of enzyme digestion. SCAPs were intermittently stimulated by complete medium, 1×10-12 mol/L, 1×10-11 mol/L, 1×10-10 mol/L, 1×10-9 mol/L and 1×10-8 mol/L rhPTH (1-34). Then SCAPs were cultured in α-MEM supplemented with different concentrations of rhPTH(1-34) and the optimal concentration of rhPTH(1-34) was determined by the alkaline phosphatase (ALP) activity. CCK8 assay was used to detect the proliferation ability of SCAPs. RT-PCR was performed to investigate the odonto/osteogenic potential of SCAPs by detecting the expression of osteocalcin (OCN), osterix (OSX), runt-related transcription factor 2 (RUNX2) and dentin sialoprotein (DSP). Results： ALP activity was significantly upregulated by 1×10-8 mol/L rhPTH(1-34), while CCK8 assay showed that there was no significant difference (P>0.05) in the proliferation ability between the control group and the rhPTH(1-34) intermittently treated group. RT-PCR analysis revealed that the odonto/osteogenic markers (OCN, OSX, RUNX2, DSP) were significantly upregulated in rhPTH(1-34) intermittently treated group as compared with control group. Conclusions：The intermittently treated rhPTH (1-34) has no effect on the proliferation of SCAPs, but can significantly promote the capacity of their odonto/osteogenic differentiation.

Objective： To investigate the regulation of miR-509-3p on the proliferation of head and neck squamous cell carcinoma (HNSCC). Methods：Real-time quantitative RT-PCR was used to detected the expression of miR-509-3p in head and neck squamous cell carcinoma cell lines HN4, HN6, HN13, CAL27 and normal oral epithelial cell line HOK. The CAL27 cells were transfected with miR-509-3p mimic and mimic NC, the expression of miR-509-3p was detected by real-time PCR; Cell proliferation experiments including CCK8, colony formation and EDU analysis have been used to verified the effect of miR-509-3p on proliferation. Results：The expression of miR-509-3p was significantly down-regulated in head and neck squamous cell carcinoma cell lines compared with HOK cells; miR-509-3p mimic can significantly increase the expression of miR-509-3p in CAL27. CCK8, colony formation and EDU analysis have shown that overexpression of miR-509-3p can significantly inhibit the proliferation of CAL27 cells. Western blot results showed that the expression levels of EGFR, p-EGFR, PI3K, p-AKT and p-MTOR were significantly decreased in cells transfected with miR-509-3p mimic. Conclusions：MiR-509-3p can affect the proliferation of CAL27 in HNSCC cell CAL27 by regulating the EGFR/PI3K/AKT/MTOR signal pathway.

Objective: To investigate the effect of berberine on the cell viability and apoptosis in human oral squamous cell carcinoma cell line HN-4, and explore the possible molecular mechanisms. Methods: The cultured HN-4 cells were treated with different concentrations of berberine for 24 or 48 h; then detected by MTS method to measure its viability. The apoptosis rate was quantified by using Annexin V-FITC apoptoticdetection kit. The mitochondrial membrane potential changes were detected with Rhodamine 123 dye by flow cytometric assay. The expression of Bax, Bcl-2, Cytochrome C, cleaved-Caspase 3 and cleaved-Caspase 9 was detected by Western Blot. Results: Berberine significantly inhibited the viability of HN-4 cells in a dose- -dependent manner. Berberine significantly increased the apoptosis rate and induced theloss of mitochondrial membrane potential on HN-4 cells.Berberine significantly upregulated the expression of pro-apoptotic proteins including Bax, Cytochrome C, cleaved-Caspase 3 and cleaved-Caspase 9, as well as upregulated the expression of anti-apoptotic Bcl-2 protein. Conclusions: Berberine significantlyinhibited the viability and induced apoptosis of HN-4 cells through activating mitochondrial-mediated pathway.

Objective：To evaluate the role of curcumin in initial adhesion and aggregation during biofilm formation by Streptococcus mutans（S.mutans）. Methods：The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by dilution method. The bacteria of S.mutans were resuspended to 1×108 CFU/mL in PBS medium after collecting them by centrifugation. The biofilm adhesion assay with different concentrations of curcumin was under the condition of 37 ℃ and the quantification was evaluated by MTT method. The aggregation assay and hydrophobicity assay were also tested. Confocal laser scanning microscope (CLSM) was used to observe the initial biofilm formation morphology. Results：The MIC and MBC of curcumin on S.mutanswere 32 mg/mL and 128 mg/mL respectively. The biofilm adhesion quantification,aggregation andhydrophobicity of S.mutanswith different concentrations of curcumin were decreased. The images showed by CLSM that the initial biofilm appeared more diffuse and looser with large gapswith different concentrations of curcumin. Conclusions：Curcumin can affect the initial adherion and aggregation during biofilm formation by S. mutans.

Objective： To investigate the biological chatacteristics of periodontal ligament stem cells (PDLSCs) in inflammation microenvironment. Methods： PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients (P-PDLSCs) and healthy controls (H-PDLSCs) by limiting dilution technique. Cell phenotype was analyzed by flow cytometry. Cell cycle analysis, MTT viability assay and clone-forming ability were used to study the proliferative ability. Osteogenic and adipogenic induction were performed to study the multipotential differentiation. Results：PDLSCs were successfully isolated from periodontitis patients and healthy controls. Both H-PDLSCs and P-PDLSCs expressed stem cell markers of mesenchymal stem cells and the overall expression patterns were similar between two groups. The proliferative ability of P-PDLSCs was strikingly higher than that of H-PDLSCs. The osteogenic and adipogenic ability of P-PDLSCs was lower than that of H-PDLSCs. Conclusions：In inflammatory microenvironment, PDLSCs exhibited increased proliferative ability but impaired differentiation capacity.

Abstract: Objective To study the structure, position and bifid of the mandibular canal by CBCT image. Methods CBCT data of 160 people were collected, and mandibular canal position in mandible, bifid from third molar to mental foramen, and three dimensional relation with the posterior teeth were analyzed. Results The average diameter of mandibular canal was 2.98mm from third molar to second premolar. Anterior loop appeared in 9.38% mandibular canal, and the average depth is 12.86mm. Mandibular canal contacted with 7.5% third molars, and the rate is higher when canal located lingually to the third molar. 28.44% mandibular canals have bifids. Conclusion CBCT image can help to observe the the structure, position and bifid of the mandibular canal, and avoid or reduce the nerve damage in treatment.

[Abstract] Objective: To explore the effect of the torque control auxiliary arch on maxillary anterior teerh. Method: 19 patients, used torque control auxiliary arch on maxillary anterior teerh with straight wire appliance, were analyzed by cephalometric results. The results were analyzed by t test. Results: U1-NA and U1-SN value invreased (P<0.01), postive torque was achieved by torque control auxiliary arch on maxillary anterior teerh. Conclusion: On maxillary anterior teeth, torque control auxiliary arch is an effective way for the toque control.

Objective ：To explore the clinical application of digital smile design (DSD) technology in the esthetics restoration of upper anterior teeth. Methods From January 2016 to December 2017, fifty patients with esthetic problems in their upper anterior teeth were included and divided into two groups randomly: experimental group (n=25) and control group (n=25). Experimental group were treated under DSD design guidance, while control group were treated with the traditional design method. The adjustment time of each temporary/final restoration and Howard B. Kay’s Classification of Altered Dental Esthetics changes in both groups were recorded. Besides, the satisfaction to the final restoration was evaluated by the patients. Results The adjustment time of the experimental group was much shorter than that in the control group (P<0.05). And the satisfaction rate of the patients to final restoration was higher in experimental group than in control group. Conclusions DSD plays an important role in the esthetic restoration of the upper anterior teeth. It helps medical staff to understand patients’ dental dynamic aesthetics information more comprehensively. It also guides the whole process of the treatment and improves the satisfaction of the patients.

Periodontitis is defined as a chronic inflammation resulting in irreversible destruction of periodontal supporting tissue. In severe cases, reduced periodontal support can lead to tooth loss. A lot of studies have been conducted to investigate true periodontal regeneration----the complete reconstruction of the damaged attachment apparatus.However, these procedures，what have been approved for clinical use,have limited success.For the last two decades,tissue engineering technology,combining cells with scaffolds and bioactive factors,might provide new approaches for periodontal regeneration . To find or prepare a suitable scaffold is the key of periodontal tissue engineering.In this review, we focus on recent studies about scaffolds in the periodontal tissue engineering.