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25 October 2020, Volume 29 Issue 5 Previous Issue    Next Issue

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Effects of MTA, iRoot SP and AH Plus on proliferation and differentiation of human periodontal ligament stem cells ZHENG Jing-jing, KANG Xin-yun, LI Shao-ming, LIU Jia-cheng, SUN Kai, GAO Ling, HOU Tie-zhou 2020, 29 (5):  449-455.  doi: 10.19439/j.sjos.2020.05.001 Abstract ( 545 )   PDF (5014KB) ( 295 )   PURPOSE: To explore the effects of MTA, iRoot SP and AH Plus on periodontal ligament stem cells. METHODS: The periodontal ligament stem cells were cloned by limiting dilution culture method. The effects of MTA, iRoot SP and AH Plus on proliferation and apoptosis of periodontal ligament stem cells were detected by MTT and Annexin-V-FITC/PI double staining. Alizarin and qRT-PCR were used to evaluate the effect of MTA, iRoot SP and AH plus on osteogenesis of periodontal ligament stem cells. SPSS 21.0 software package was used for statistical analysis. RESULTS: MTA showed mild toxicity at 24 and 48 hours, AH Plus showed mild toxicity at 24 h. iRoot SP was the least (P<0.05) compared to MTA and AH Plus. The effect of three kinds of materials on apoptosis of periodontal ligament stem cells gradually decreased with the prolongation of time. Compared with the control group, the three kinds of materials were toxic at 3 d, the toxicity of MTA was the strongest and the toxicity of iRoot SP was the lowest(P<0.05). Mineralization nodules in MTA and iRoot SP group were significantly higher than those in AH Plus and control group. The expression of OC, RUNX2, COL1A and ALP gene was higher at 7, 14, 21 d than in the control group and the expression of iRoot SP mineralization was the greatest(P<0.05). CONCLUSIONS: The hardened iRoot SP is non-toxic to human periodontal ligament stem cells. Osteogenic ability and mineralization capacity of hardened iRoot SP on human periodontal ligament stem cells are better than MTA. References | Related Articles | Metrics

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Effect of different fluence rates applied in curcumin-photodynamic therapy on Candida albicans biofilms MA Jing, LI Ji-yang, YANG Qiao-zhen, BAI Yu, ZHANG Cheng, SUN Hong-ying 2020, 29 (5):  456-461.  doi: 10.19439/j.sjos.2020.05.002 Abstract ( 319 )   PDF (5623KB) ( 195 )   PURPOSE: In this study, the inactivation effect of different fluence rates on Candida albicans biofilms during curcumin-photodynamic therapy was investigated in vitro. METHODS: The standard Candida albicans and clinical isolated Candida albicans were selected as model fungus and different fluence rates (12, 22, 42, 62, 82, 102 mW/cm2) during curcumin-photodynamic therapy were applied to inactivate Candida albicans biofilm. To evaluate the inactivation effect, XTT assay and Live/Dead kit were employed to quantify and visualize the activities of Candida albicans biofilms. The data were analyzed with SPSS 19.0 software package. RESULTS: When 40 μmol/L of curcumin was applied followed by 4 min illumination, both standard Candida albicans and clinical isolated Candida albicans biofilms were greatly inactivated along with the increase of fluence rates. When fluence rate increased to 102 mW/cm2, there was no significant difference between the experimental group and the previous experimental group(P>0.05). CONCLUSIONS: Fluence rate plays an important role in inactivation of Candida albicans biofilms during curcumin-photodynamic therapy, with optimized value of fluence rate of 82 mW/cm2 in this study. References | Related Articles | Metrics

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Influence of vitexin on the expression of inflammatory cytokines in dental pulp stem cells induced by lipopolysaccharide NIU Chen-guang, LI Jia-yang, YU Li-ming, CHEN Dong, WEI Xiao-ling 2020, 29 (5):  462-465.  doi: 10.19439/j.sjos.2020.05.003 Abstract ( 323 )   PDF (3188KB) ( 193 )   PURPOSE: To investigate the effect of vitexin (VTX) on the expression of inflammatory cytokines in human dental pulp stem cells(hDPSCs) induced by lipopolysaccharide(LPS), and to explore the underlying mechanism. METHODS: hDPSCs were isolated and cultured, and CCK-8 method was used to detect the effect of VTX on proliferation of hDPSCs. hDPSCs were randomly divided into 4 groups: blank group (without LPS and VTX),LPS group (2 μg/mL LPS),2 μg/mL LPS + 25 μmol/L VTX,2 μg/mL LPS + 50 μmol/L VTX. The cells of all groups were cultured for 48 h. The gene levels of IL-1β, IL-6 and IL-8 in hDPSCs were detected by real time qPCR(RT-qPCR). The change of COX-2 and MAPKs signaling pathways were detected by Western blot. SPSS 16.0 software package was used for statistical analysis. RESULTS: When the VTX concentration was less than 200 μmol/L, the cell viability was not affected(P>0.05). VTX at 25 and 50 μmol/L significantly reduced LPS-induced expression of IL-1β, IL-6 and IL-8 at gene levels and COX-2 at protein level (P<0.05). CONCLUSIONS: VTX significantly inhibited the activation of ERK and p38 signaling pathway. VTX can reduce LPS-induced inflammatory cytokine expression in hDPSCs via restraining the activation of ERK and p38 signaling pathway. References | Related Articles | Metrics

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Anti-aging effect of dental pulp stem cells on skin fibroblasts LI Yue-ling, YANG Jia-yin, XU Rui 2020, 29 (5):  466-470.  doi: 10.19439/j.sjos.2020.05.004 Abstract ( 309 )   PDF (3797KB) ( 161 )   PURPOSE: To investigate the effect of dental pulp stem cells on the senescence and proliferation of skin fibroblasts, and to explore the underlying mechanism. METHODS: Dental pulp stem cells (DPSCs) were extracted from human dental pulp and then skin fibroblasts were co-cultured with DPSCs. The experiment was divided into three groups: control group (single skin fibroblasts culture), conditioned medium group (skin fibroblasts cultured with DPSCs conditioned medium), direct co-culture group (skin fibroblast cultured with DPSCs in Transwell chambers). After co-culture, the senescence of fibroblasts was detected by SA-β-gal staining.CCK-8 method was used to detect the activity of fibroblasts. The cell cycle of fibroblasts was analyzed by flow cytometry. mRNA and protein expression levels of senescence related proteins p21, p53 and pRb were detected by RT-PCR and Western blot. SPSS 13.0 software package was used for statistical analysis of the experimental data. RESULTS: Compared with the control group, skin fibroblasts in the latter two groups showed decreased expression of SA-β-gal and increased proliferation ability. Cell cycle test showed that skin fibroblasts decreased in G1 phase and increased in S and G2 phase in conditioned medium group and direct co-culture group. RT-PCR and Western blot results showed decreased expression levels of p53, p21 mRNA and protein, and increased levels of pRb in conditioned medium group and direct co-culture group. CONCLUSIONS: Dental pulp stem cells and their conditioned medium have anti-aging effect on skin fibroblast. The results of this study provide theoretical basis for the clinical application of dental pulp stem cells in anti-aging. References | Related Articles | Metrics

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Effect of different root canal file tapers on fracture strength of root canal wall QIU Xiao-jian, XIAO Shan-she, GU Xue-lian, ZHU Lai-kuan, JIANG Qian 2020, 29 (5):  471-475.  doi: 10.19439/j.sjos.2020.05.005 Abstract ( 449 )   PDF (3834KB) ( 205 )   PURPOSE: To compare the effects of different nickel-titanium rotary tapers on fracture strength of root canal and the application value of finite element analysis in root canal therapy. METHODS: Twenty four mandibular premolars were selected and all crowns were removed. All samples were randomly divided into 4 groups: A, B, C and D. Group A and C were instrumented with Z-K3 nickel titanium file as 0.04 taper for root canal preparation. Group B and D were instrumented with Z-K3 nickel titanium file as 0.06 taper. Group C and D were sliced into 2 mm thick slices 3 times after root canal preparation. Two teeth were selected from group A and group B and scanned with micro-CT. The model was imported into different softwares to optimize. The assembly model was built and imported into ANSYS for finite element analysis. Universal testing machine and force bar were used to apply 100 N force to samples until fracture occurring at any place of tooth sample. The fracture load was recorded and comparative analysis was conducted. RESULTS: The results of finite element analysis showed that the maximum stress of 0.04, 0.06 taper models was 138.88 MPa and 78.812 MPa, respectively. The average fracture load of group A, B was 490.12 N and 501.83 N, respectively. In group C and D, the maximum average fracture load was 93.61 N and 141.53 N, respectively. From the neck to the middle and then to the tip, the average fracture load of root canal decreased in turn. CONCLUSIONS: For normal form mandibular premolars, the fracture strength of the root instrumented with 0.06 taper nickel titanium rotary file was significantly higher than that instrumented with 0.04 taper. Three dimensional finite element analysis could guide dentists to choose a suitable taper file in root canal treatment to reduce the incidence of root fracture. References | Related Articles | Metrics

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Construction of ADAM28 shRNA interference vector and its inhibitory effect on human periodontal ligament stem cells ZHAO Zheng, QIU Hai-yan, FU Lan, LI Jie 2020, 29 (5):  476-481.  doi: 10.19439/j.sjos.2020.05.006 Abstract ( 213 )   PDF (4356KB) ( 144 )   PURPOSE: To investigate the inhibition of ADAM28 shRNA interfering vector on ADAM28 gene expression in human periodontal ligament stem cells(HPDLSC), and provide experimental evidence for gene therapy against congenital hypoplasia of tooth root(CHTR) disease. METHODS: Four pairs of shRNA specific interfering fragments were designed, synthesized, and connected with pGPU6/GFP/Neo vector. ADAM28 shRNA interfering vector was constructed and identified, and transfected into HPDLSC for 48 h, and then the inhibition efficiency was detected by real-time fluorescence quantitative RT-PCR（qRT-PCR）and Western blot. Statistical significance was assessed by SPSS 21.0 software package. RESULTS: Enzyme digestion and sequencing identification demonstrated that the double strands shRNA was correctly inserted into the expression vector pGPU6/GFP/Neo, and the recombinant interfering vector was successfully constructed and highly transfected into HPDLSC. QRT-PCR and Western blot showed that pGPU6/GFP/Neo-ADAM28-shRNA1-4 had significant inhibition efficiency, and shRNA1 had the highest inhibition efficiency. There were significant differences between ADAM28-shRNA1-4 group and non-transfection group, negative control group, respectively(P<0.05). CONCLUSIONS: ADAM28 shRNA interference vector can effectively inhibit ADAM28 gene expression in HPDLSC. References | Related Articles | Metrics

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Effect of concentrated growth factor on the biological properties of MC3T3-E1 osteoblasts WANG Song-song, ZHANG Yun-tao, LIU Ke-ke, ZHANG Ling-nan, DUAN Xin 2020, 29 (5):  482-486.  doi: 10.19439/j.sjos.2020.05.007 Abstract ( 215 )   PDF (3436KB) ( 157 )   PURPOSE: To observe the effect of concentrated growth factor(CGF) on the biological properties of osteoblasts. METHODS: MC3T3-E1 cells were cultured in CGF environment and a blank control group was established. The adhesion of osteoblasts to CGF surface was observed by scanning electron microscopy. Cell proliferation and alkaline phosphatase(ALP) activity were detected at 1, 4 and 7 d by Cell Counting Kit-8 (CCK-8) and Alkaline Phosphatase Assay Kit. The expression of mineralized nodules and osteogenesis-related gene Runx2 was observed by alizarin red staining. CGF extract was cultured for 24 h. Peptide staining was used to observe morphological changes in the cytoskeleton. SPSS 21.0 software package was used for statistical analysis. RESULTS: CCK-8 showed cells incubated for 1, 4 and 7 d in the experimental group had a stronger proliferation ability compared with the control group, and the difference was statistically significant (P<0.05). ALP activity test showed that there was no significant difference between the experimental group and the control group (P>0.05) at 1 d; but after 4 days of culture, cell in the experimental group had an increased ALP activity compared with the control group, and the difference was statistically significant(P<0.05). The results of alizarin red staining showed that the number of calcified nodules in the CGF group increased and the area was larger. In the phalloidin staining and DAPI staining, the number of cells in the CGF group increased, the cell spreading surface increased, and the actin shape was clearer. CGF significantly promoted Runx2 mRNA expression(P<0.05). CONCLUSIONS: High concentration of CGF can promote the proliferation and differentiation of MC3T3-E1 cells and the expression level of related osteogenic gene Runx2. References | Related Articles | Metrics

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Evaluation on the fracture resistance of dental tissues after guided plate-mediated precision minimally invasive root canal treatment LI Ze-yu, WANG Ling-xiang, ZHU Xue-chen, NIU Cheng-guang, HUANG Zheng-wei, SUN Hui-bin 2020, 29 (5):  487-491.  doi: 10.19439/j.sjos.2020.05.008 Abstract ( 287 )   PDF (4415KB) ( 171 )   PURPOSE: In order to achieve accurate and minimally invasive root canal treatment and enhance the fracture resistance of tooth tissue after root canal therapy, this study explores digital guided mediated minimally invasive root canal treatment and compares it with conventional root canal treatment to provide a more favorable method for clinical practice. METHODS: Forty freshly extracted first permanent molars were randomly divided into control group and experimental group. Teeth in the control group were treated with conventional root canal treatment, while teeth in the experimental group were treated with precise minimally invasive root canal treatment. The difference between the time of opening of the pulp chamber and the area of the open pores on the total area of the occlusal surface was compared. Loading test was carried out on the subjects using a universal testing machine, and the fracture resistence of the tooth tissues of the two groups were measured. Statistical analysis was performed using SPSS 24.0 software package. RESULTS: In the control group, the time required for opening the pulp chamber was (1.85±0.05) min, the open pore area was (9.18±0.48)% of the total occlusal area, and the load of the tooth tissue was (1.48±0.07) kN. In the experimental group, the time required was (0.72±0.10) min, the open pore area was (3.53±0.13)% of the total occlusal area, and the load of the tooth tissue was (1.81±0.03) kN. The higher the loading value, the stronger the fracture resistance of the tooth tissue. Compared with traditional root canal treatment, digital guided plate mediated minimally invasive root canal treatment had the advantages of short time, small access cavity and strong fracture resistance of tooth tissue. The difference between the two groups was significant (P<0.01). CONCLUSIONS: Digital guided plate-mediated accurate minimally invasive root canal treatment can reduce the occlusal area, shorten the operation time beside the chair, retain more healthy tooth tissue, enhance the fracture resistance of tooth tissue after root canal treatment, and improve the retention rate of affected teeth. References | Related Articles | Metrics

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Osteogenic stimulation of human dental pulp stem cells with gelatin-hydroxyapatite-tricalcium phosphate scaffold CHANG Si-jia, YANG Liu, LI Ran 2020, 29 (5):  492-498.  doi: 10.19439/j.sjos.2020.05.009 Abstract ( 278 )   PDF (5527KB) ( 154 )   PURPOSE: To investigate the osteogenic stimulation effect of gelatin-hydroxyapatite-tricalcium phosphate (gelatin-HA-TCP) scaffold on human dental pulp stem cells(hDPSCs). METHODS: Gelatin scaffold and gelatin-HA-TCP scaffold were developed via solution casting/particle washing method, and the physical and mechanical properties of the scaffolds were examined using scanning electron microscopy and a universal testing machine, respectively. The stress intensity(SS) and elastic modulus(E) of the scaffold were measured by vertical electronic universal testing machine. The osteogenic medium was divided into control group (osteogenic medium), experimental group 1 (gelatin scaffold extract + osteogenic medium) and experimental group 2(gelatin-HA-TCP scaffold + osteogenic medium) according to different mediums. The effects of scaffolds on proliferation and alkaline phosphatase(ALP) activity of hDPSCs were evaluated by CCK8 and ALP staining. The expression of osteogenic factors in hDPSCs was detected by alizarin red S staining and reverse transcription-polymerase chain reaction(RT-PCR). Data were processed by SPSS 20.0 software package. RESULTS: Compared with gelatin scaffold, gelatin-HA-TCP scaffold had higher SS and lower E(P<0.05); CD146 and CD105 were positively expressed in hDPSCs, and CD34 and CD45 were negatively expressed in hDPSCs. The number of cells on the 3rd, 5th and 7th day of experimental group 1 was significantly higher than that of the control group (P<0.05); The number of cells on the 1st, 3rd, 5th and 7th day of experimental group 2 was significantly higher than that of the control group (P<0.05); ALP activities on the 4th, 7th and 12th day of experimental group 2 were significantly higher than those of the control group and experimental group 1(P<0.05). Compared with the control group, visual fields were red in both experimental groups, and the unevenly distributed calcified precipitation was also found in both experimental groups. The mRNA expression level of Runt-related transcription factor 2(Runx2) on the 4th day of experimental group 1 and experimental group 2 was significantly higher than that of the control group(P<0.05). The mRNA expression level of osterix (OSX) on 7th day of experimental group 2 was significantly higher than that of the control group(P<0.05). The mRNA expression level of bone sialoprotein (BSP) on the 4th day of experimental group 2 was significantly higher than that of the control group and experimental group 1 (P<0.05). CONCLUSIONS: The microscopic characterization of gelatin-HA-TCP scaffold is similar to that of natural bone structure with significant osteoinductive effect on the proliferation and differentiation of hDPSCs, and may be a promising biomaterial for bone tissue engineering. References | Related Articles | Metrics

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Different concentration of lidocaine used for an exodontia of the impacted mandibular third molar ZHAI Qin-kai, GAO Chao, SHEN Mo-lun, ZHAO Jun, YE Hu, CHU De-qiang, HAO Xin-he 2020, 29 (5):  499-503.  doi: 10.19439/j.sjos.2020.05.010 Abstract ( 948 )   PDF (3799KB) ( 176 )   PURPOSE: To investigate the anesthesia outcomes of 1% lidocaine with 1∶100 000 epinephrine (EPI) for inferior alveolar nerve, lingual nerve and buccal nerve block, compared with 2% lidocaine with 1∶100 000 EPI. METHODS: A study with a cross-over design, with each patient also serving as their own control, was implemented to estimate the clinical outcomes. Predictor variable was 1% lidocaine with 1∶100 000 EPI versus 2% lidocaine with 1∶100 000 EPI. Outcome variables were patients’ responses to pain on injection, onset time of anesthetizing, efficacy of anesthesia, and the time to sensation return for the lower lip and tongue. Patients reported pain level at every experimental stage with a 10-point Numerical Rating Scale(NRS). Three weeks later, the patients were tested with the alternate drug combinations. The same outcomes were assessed. A verification of treatment difference was performed using SPSS 17.0 software package. RESULTS: Twenty-one patients were recruited and completed the study protocol. Sixty-two percent of the patients were women and 38% were men with a median age of 24 years [interquartile range (IQR), 20-30 yr]. Patients reported significantly lower pain scores with 1% lidocaine (1.09,95%CI,0.77-1.41) on injection, compared with 2% lidocaine (1.66, 95%CI, 1.33-1.99) (P=0.010). Patients undergoing 1% lidocaine with 1∶100 000 EPI (52-63 s) had a markedly quicker onset time of anesthetizing than those using 2% lidocaine with 1∶100 000 EPI (259-335 s, P=0.000). The efficacy of anesthesia between 2 groups was not significantly different (P=0.751). Among the patients with the pain values of 1~3, there were 9 patients(100%) perceiving slight pain when splitting teeth was performed in 1% lidocaine group, while 4patients(57%) felt slight pain when elevating soft flaps was performed and 3 patients(43%) perceived mild pain when splitting teeth was performed in 2% lidocaine group (P=0.019). The time to sensation return for the lower lip and tongue was significantly different between the 2 drug formulations (P=0.000), with an extended period of average 61 min (52-69 min) in 2% lidocaine group. CONCLUSIONS: 1% lidocaine with EPI plays a similar role in clinical outcomes for inferior alveolar nerve, lingual nerve and buccal nerve block as 2% lidocaine with EPI, which produces lower pain on injection as well as a relatively short time to sensation return. The reasons for slight pain during surgical operation are a relative lower efficacy of anesthesia on the inferior alveolar nerve in 1% lidocaine group, and on the buccal nerve anesthesia in 2% lidocaine group. References | Related Articles | Metrics

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Accuracy of 6D computed-derived implant guides made in China for dental implant surgery in edentulous patients TU Ye-ying, ZHOU Jian, YU Yan-chun, FAN Ming-xing, PAN Hai-song, LIN Hai-yan 2020, 29 (5):  504-508.  doi: 10.19439/j.sjos.2020.05.011 Abstract ( 420 )   PDF (4233KB) ( 197 )   PURPOSE: To evaluate the accuracy of 6D computed-derived implant guides made in China, in order to provide methods and basis for reducing deviation. METHODS: 3D rapid prototyping technique was used to fabricate implant guides for auxiliary surgical implantation in edentulous patients, and the position deviation between the preoperative design and the actual implant was measured. Sixteen edentulous patients with 172 implantation sites were measured. In 10 patients, six implants were implanted in the maxilla, 4 implants in the mandible, and 6 implants were implanted both in the maxilla and mandible of 6 patients. A total of 28 implants were tilted implant in 14 patients. Preoperative cone-beam CT(CBCT) data were imported into the 6D Dental Planning Software to design and make the implant guides. Digital guides were used to assist implant placement. Preoperative design and postoperative CBCT were imported into the software for 3D reconstruction and registration, and then exported to Geomagic Studio software for analysis to obtain the deviation between the preoperative design and the implantation, so as to analyze the accuracy of the guides. The differences were analyzed by SPSS 25.0 software package with paired t-test and single factor analysis of variance. RESULTS: The distance deviation of implant neck center point was (0.83±0.27) mm and the horizontal deviation was (0.60±0.21) mm. The distance deviation of implant bottom center point was (1.11±0.35) mm, and the vertical deviation was (0.45±0.19) mm. The angle deviation was (3.16±1.73)°. CONCLUSIONS: The 6D computed-derived implant guides made in China can improve the accuracy and efficiency of implant surgery for edentulous patients and obtain a better long-term clinical effect to meet clinical requirements well. Since the deviation is similar to other implant guide plate systems that reported aborad, it must be taken into account in the process of clinical design, in order to avoid risks and unnecessary complications. This method is worthy of wide clinical application. References | Related Articles | Metrics

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Status of tooth loss, prosthodontic treatment and oral health-related quality of life of Shanghai elderly people GUO Xiao-jing, ZHANG Ying, ZHANG Hao, ZENG Xiao-li, MAO Yan-min, DONG Hua, HUA Min, JIANG Yi-wei, WANG Yan 2020, 29 (5):  509-514.  doi: 10.19439/j.sjos.2020.05.012 Abstract ( 384 )   PDF (4077KB) ( 272 )   PURPOSE: The aim of the present study was to investigate oral health status of the elderly in Shanghai using Eichner index dental classification system, and to discuss the relations between tooth loss, prosthodontic treatment and the impact on oral health-related quality of life(OHRQoL). METHODS: A total of 747 subjects aging 65-74 years old were selected by multistage stratified cluster sampling method. Clinical examination and questionnaires of the Fourth National Oral Health Survey of China were used for the study, and data of tooth loss, OHRQoL were analyzed using non-parametric test and binary logistic regression with SPSS 19.0 software package. RESULTS: 79.1% of the subjects had problem of missing teeth, while 35% of them never received any kind of dental prosthesis. Grouping by the Eichner index, only A1, A2 and C3 group were scored above the average, while group B had the lowest general oral health assessment index(GOHAI) score. The scores of GOHAI were significantly correlated to dental prosthodontic treatment, overall health status and Eichner index(P<0.05). Except for group C2 due to the small sample size, the scores of GOHAI in most of the untreated subjects were lower than those who had prosthesis. Among the subjects with missing teeth but without prosthesis, 81.2% of the subjects thought they had no problem with their teeth or the problem did not matter. CONCLUSIONS: Tooth loss is a serious problem among the elderly in Shanghai, but only a few of them have received dental prosthodontic treatment. The OHRQoL of the elderly is related to tooth loss, dental prosthodontic treatment and overall health. Oral health education should be strengthened for the elderly people with missing teeth, to replace their missing teeth timely and improve their quality of life. References | Related Articles | Metrics

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Soft and hard tissue changes and vertical correlation of early skeletal Class Ⅲ malocclusion treated with Sander Ⅲ appliance FU Xue-fei, ZOU Xian-yu, XU Wei-hua 2020, 29 (5):  515-518.  doi: 10.19439/j.sjos.2020.05.013 Abstract ( 507 )   PDF (2814KB) ( 246 )   PURPOSE: To explore the correlation between the soft and hard tissue changes and the vertical direction of early skeletal Class Ⅲ malocclusion treated with Sander Ⅲ appliance. METHODS: Thirty-two patients with skeletal Class Ⅲ malocclusion who underwent Sander Ⅲ appliance correction were enrolled. The changes of soft and hard tissues were observed before and after treatment for 12 months. The correlation between soft tissue and vertical direction was analyzed. SPSS 25.0 software package was used for statistical analysis. RESULTS: After 12 months of treatment, SNB decreased (P <0.05), ANB, A-PTV, Go-Me increased (P<0.05), soft tissue index LL-LI increased (P<0.05), LL-EP decreased (P<0.05). L1/MP was reduced after treatment (P<0.05), and U1E-PTV was increased (P<0.05). Correlation analysis showed that UL-UI was positively correlated with tilt angle, U1E-PP and U6E-PP(P<0.05); LL-LI was negatively correlated with tilt angle, U1E-PP and U6E-PP (P<0.05). Sn-UL/FH and U6E-PP were positively correlated (P<0.05). CONCLUSIONS: Sander Ⅲ appliance can effectively correct the soft and hard tissue deformity of patients with early skeletal Class Ⅲ malocclusion. The shape of the lip tends to be coordinated with the improvement of hard tissue. The soft tissue index is closely related to the vertical direction of the hard tissue. References | Related Articles | Metrics

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Immunopathology and immunomodulatory roles of interleukin-12 in periodontal disease WU Yu-cong, CHENG Ya-nan, CHEN Shao-shan, YANG Bin, LU Li-ying 2020, 29 (5):  519-523.  doi: 10.19439/j.sjos.2020.05.014 Abstract ( 324 )   PDF (4278KB) ( 158 )   PURPOSE: To investigate the immunopathology and immunomodulatory roles of interleukin-12 (IL-12) in periodontal disease. METHODS: Ninety-eight patients with chronic periodontitis from January 2016 to January 2019 were enrolled and divided into mild group (30 cases), moderate group (35 cases) and severe group (33 cases) according to the severity of periodontitis; meanwhile, 30 healthy subjects who underwent periodontal examination in our hospital were selected as the control group. Clinical periodontal indicators including probing depth(PD), attachment loss(AL), plaque index(PLI), bleeding index(BI), Th cell expression (Th1, Th2, Th17) in peripheral blood, IL-12 levels in gingival crevicular fluid (GCF) and serum were measured. SPSS 20.0 software package was performed to analyze the correlation between IL-12 levels in GCF and serum and Th1, Th2, Th17, PD, AL, PLI, and BI. RESULTS: The differences of PD, PLI and BI among the groups were statistically significant(P<0.05). The levels of PD, PLI and BI in the mild, moderate and severe group were significantly higher than those in the control group (P<0.05). The difference of AL index among mild, moderate and severe group was statistically significant(P<0.05). The PD, AL, PLI, and BI in the moderate and severe group was significantly higher than those in the mild group(P<0.05), and the severe group was significantly higher than the mild group(P<0.05). Th1, Th2 and Th17 were significantly higher in the mild, moderate and severe group than in the control group(P<0.05); the moderate, severe group was significantly higher than the mild group in terms of Th1, Th2 and Th17 (P<0.05), and the severe group was significantly higher than the moderate group (P<0.05). The IL-12 levels in GCF and serum of the mild, moderate, and severe groups were significantly higher than those of the control group (P<0.05); IL-12 levels in the the moderate and severe groups were significantly higher than those in the mild group (P<0.05), and the IL-12 were significantly higher in the severe group than in the moderate group (P<0.05); IL-12 was positively correlated with PD, AL, PLI, BI, Th1, Th2 and Th17(P<0.05). H-E staining showed there were fewer lymphocytes in the mild group, more lymphocytes in the moderate group, and dense lymphocytes in the severe group with significant hemorrhage in intercellular mesenchyme. The IL-12 protein positive staining results were expressed in gingival tissue lymphocyte pulp with significant brown observed. The positive staining of IL-12 protein in the gingival tissues in the mild, moderate and severe group was significantly higher than in the control group, and the staining was aggravated with mild, moderate and severe inflammatory changes. CONCLUSIONS: IL-12 is involved in the immunoregulatory mechanism of periodontal disease and may be a key pro-inflammatory cytokine in the development of periodontitis. References | Related Articles | Metrics

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Analysis of mandibular canal in patients with prognathism and its clinical significance YE Li-juan, BO Fang, LIU Jing, WANG Yue-ping 2020, 29 (5):  524-527.  doi: 10.19439/j.sjos.2020.05.015 Abstract ( 528 )   PDF (2950KB) ( 301 )   PURPOSE: The aim of this study was to investigate the position and course of mandibular canal in patients with prognathism using cone-beam CT(CBCT),and explore its clinical significance. METHODS: The mandibles of 28 patients with skeletal Class Ⅲ prognathism (10 males and 18 females) and 20 normal people(12 males and 8 females) were analyzed on CBCT. The position and course of mandibular canal from the lowest point of mandibular foramen to the first molar were measured at five specific sections from the mandibular foramen to the mandibular first molar area, including inner and outer diameter, mandibular bone thickness ,distance between mandibular canal and distance to the buccal and lingual bone cortex, and the inferior border of mandible bone. Statistical analysis was performed using SPSS 17.0 software package. RESULTS: The mandibular bones of patients with prognathism gradually thickened from the mandibular ramus to the forepart of the mandibular angle and thinned forward to the position where the mandibular first molar projected on the mandibular bone. Cortical bone of buccal side of the mandibular ramus thickened forward to the mandibular angle and thinned to the mandibular body. The width of buccal bone marrow cavity and diameter of mandibular bone were statistically different between genders. CONCLUSIONS: This study found that the difference between the thickness of the mandibular ramus in patients with mandibular protrusion from the controls was mainly due to the difference between the width of the buccal bone marrow cavity. CBCT can accurately locate the mandibular canal and display anatomic structures. References | Related Articles | Metrics

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Expression and clinical significance of Spindly and Bub3 in oral squamous cell carcinoma ZHENG Jing, LI Tian-ke, BAO Yang, ZHANG Su-xin 2020, 29 (5):  528-532.  doi: 10.19439/j.sjos.2020.05.016 Abstract ( 606 )   PDF (3806KB) ( 126 )   PURPOSE: To investigate the expression and significance of Spindly and Bub3 in oral squamous cell carcinoma(OSCC). METHODS: Sixty-five patients with OSCC admitted to the Fourth Hospital of Hebei Medical University from March 2017 to March 2019 were enrolled. RT-PCR was used to detect the expression of Spindly and Bub3 mRNA in oral squamous cell carcinoma and adjacent normal tissues from the patients. OSCC cell line was cultured. After siRNA transfection interference with the expression of Spindly and Bub3 genes, cell viability was detected by MTT assay, and the cell migration ability was detected by scratch test. Statistical analysis was performed with SPSS 22.0 software package RESULTS: The expression levels of Spindly and Bub3 mRNA in OSCC were significantly higher in adjacent tissues(P<0.05). The expression of Spindly and Bub3 mRNA was related to TNM staging, clinical staging and lymph node metastasis (P<0.05). The 5-year survival rate of patients with high expression of Spindly, Bub3, Spindly/Bub3 were significantly higher than the counterparts with low expression, and the 5-year survival rate of patients with high expression of Spindly/Bub3 was significantly lower than that of patients with high expression of Spindly and Bub3(P<0.05). The expression level of Spindly in siRNA-Spindly group was significantly lower than that in Spindly negative control group and blank control group, and the expression level of Bub3 in siRNA-Bub3 group was also significantly lower than that in Bub3 negative control group and blank control group. The expression level of Spindly in siRNA-Spindly group was significantly lower than that in Spindly negative control group and blank control group, and the expression level of Bub3 in siRNA-Bub3 group was also lower than that in Bub3 negative control group and blank control group. The migration ability of cells in siRNA-Spindly group at 24 and 48 hours was significantly lower than that in Spindly negative control group and blank control group; the migration ability at 24 and 48 hours was significantly lower than that of Bub3 negative control group and blank control group(P<0.05). CONCLUSIONS: Spindly and Bub3 are highly expressed in OSCC. Specific inhibition of Spindly and Bub3 gene expression can reduce the proliferation and migration of cancer cells, which might be used as one of the targets for the treatment of OSCC. References | Related Articles | Metrics

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Effect of IL-10 gene polymorphism on periodontal microecology in patients with periodontitis CHEN Xiao-hua, XU Mao-lin 2020, 29 (5):  533-538.  doi: 10.19439/j.sjos.2020.05.017 Abstract ( 256 )   PDF (4275KB) ( 140 )   PURPOSE: To investigate the effect of IL-10 gene polymorphism on periodontal microecology in patients with periodontitis. METHODS: Seventy-nine patients with periodontitis (experimental group) and 50 healthy individuals (control group) visiting Zibo First Hospital from June 2018 to March 2019 were enrolled. The experimental group was further divided into two groups according to the severity of periodontitis, namely moderate periodontitis (n=47) and severe periodontitis (n=32). Real-time quantitative PCR was used to detect the level of bacterial colonization in the subgingival plaque of all subjects. The genotype and allele frequencies at-1082,-819, and-592 loci in IL-10 were detected by PCR. Multivariate analysis was used to explore the relationship between IL-10 genotypes and bacterial colonization level in subgingival plaque. The data were processed by SPSS 2.0 software package. RESULTS: Actinomycetes actinomycetes (A.a) colonization in patients with moderate periodontitis was significantly lower than that of patients with severe periodontitis (P<0.05). The amount of Porphyromonas gingivalis(P.g) and A.a in patients with moderate periodontitis and severe periodontitis was significantly higher than that in the control group (P<0.05). The proportion of CC genotypes in the-819 locus of patients with moderate periodontitis was significantly lower than that of the control group, and the proportion of TT genotype was significantly higher than that of the control group(P<0.05). The proportion of CC, TC and TT genotypes showed no significant difference between patients with moderate periodontitis and those with severe periodontitis (P>0.05). The proportion of CC genotypes in the-592 locus of patients with moderate periodontitis was significantly lower than that of the control group, and the proportion of AA genotype was significantly higher than that of the control group (P<0.05). In moderate periodontitis, A.a colonization amount at-592 gene locus of AA genotype was significantly higher than that of AC genotype(P<0.05). In moderate periodontitis, A.a colonization amount at of-819 gene locus of TT genotype was significantly higher than that of TC genotype (P<0.05). Multivariate analysis showed that IL-10-592-AA genotype and-819-TT genotype were closely related to A.a colonization in moderate periodontitis (P<0.05). CONCLUSIONS: IL-10 gene polymorphism is the influencing factor of subgingival microecological environment in patients with moderate periodontitis, among which IL-10-592-AA genotype and-819-TT genotype have the most obvious correlation with A.a colonization level. References | Related Articles | Metrics

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Analysis on the influencing factors of long-term survival of implants during lateral maxillary sinus floor elevation CHEN Wen-yuan, CHEN Xiang, LIN Xiao-wei, XU Liang 2020, 29 (5):  539-543.  doi: 10.19439/j.sjos.2020.05.018 Abstract ( 425 )   PDF (3676KB) ( 173 )   PURPOSE: To investigate the long-term effects of residual bone height (RBH), maxillary sinus membrane perforation, and cavities on survival of implants with lateral maxillary sinus lifting (MSFA). METHODS: Fifty-six patients (98 implants) who underwent MSFA from 2005 to 2009 and followed up till 2019 were enrolled. RBH was assessed using a series of panoramic and periapical X-ray films. Based on the presence of RBH, sinus membrane perforation, cavities, the cumulative survival rate (CSR) were evaluated using log-rank test and risk ratio of implant failure, SPSS 21.0 software package was used to analyze the data. RESULTS: The residual bone height of implants with sinus membrane perforation was significantly larger than those without sinus membrane perforation. The residual bone height of the survival implants was significantly larger than that of the failed implants(P<0.05), but there was no significant difference in the residual bone height between gender, smoking and cavities(P>0.05). The total CSR of 10 years after implantation by MSFA was 94.5%, of which the females was significantly higher than that of males, non-smokers was significantly higher than that of smokers, and RBH≥3 mm was significantly higher than that of RBH<3 mm(P<0.05). However, there was no significant difference in CSR between sinus membrane perforation and non-sinus membrane perforation. CONCLUSIONS: Implants with RBH<3 mm have lower CSR, and the survival is acceptable under proper oral hygiene maintenance conditions. Sinus perforation and cavity do not affect the survival of lateral MSFA implants. References | Related Articles | Metrics

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A cross-sectional survey of attention and knowledge level among dental students in Jiangxi province during the epidemic period of COVID-19 ZENG Yi-xuan, LI Zhi-hua, ZHU Jia, LI Xiao-hui, HU Zheng, HUANG Min, OUYANG Zhi-qiang 2020, 29 (5):  544-549.  doi: 10.19439/j.sjos.2020.05.019 Abstract ( 320 )   PDF (4650KB) ( 150 )   PURPOSE: To investigate the level of attention and knowledge level of dental students in Jiangxi province during the epidemic period of COVID-19, and provide data support for optimizing the training program of dental professionals in the future. METHODS: Two thousand and sixty-five valid questionnaires were collected from stomatological colleges in Jiangxi province through internet. SPSS 20.0 software was used for statistical analysis, Chi-square test and binary logistic regression were used for single factor and multi factor analysis. RESULTS: According to the survey, 74.72% of dental students expressed their concern about the epidemic situation, and 75.93% expressed that they checked the number of confirmed cases in China once or more every day. Students with higher education background, licensed doctor certificate and better family status paid more attention to the epidemic period and frequently checked the information(P<0.05). The categories of information most concerned by all respondents was data such as the number of newly diagnosed patients and the number of cured cases, followed by the diagnosis and treatment of patients with COVID-19.The average score of knowledge about epidemic situation was 5.60±1.88. Analysis of influencing factors showed that the knowledge level of women was higher than that of men（OR=1.371,95%CI:1.143-1.644）.Medical students from Hubei province had a good level of knowledge, high education, party members, and students with medical qualifications had a high level of knowledge about epidemic situation of COVID-19(P<0.05). CONCLUSIONS: The epidemic period of COVID-19 is a high concern among dental students in Jiangxi province , and the awareness rate of related knowledge is low. In order to improve the quality of dental personnel training, the medical colleges or school should strengthen the training of students' operations in the hospital, and add relevant courses of public health emergency in the training program. References | Related Articles | Metrics

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Comparison of two types of T-shaped coronectomy applied in extraction of impacted mandibular third molars WANG Kun-peng, YUAN Yi-jie, ZHU Jia-qi, LI Bo-long, MENG Zhao-song, ZHANG Ting-ting 2020, 29 (5):  550-553.  doi: 10.19439/j.sjos.2020.05.020 Abstract ( 618 )   PDF (2802KB) ( 371 )   PURPOSE: To compare the clinical efficiency of two types of T-shaped coronectomy applied in extraction of impacted mandibular third molars.METHODS: One hundred and twenty patients meeting with the criteria were randomly divided into 2 groups. Two types of T-shaped coronectomy were applied in extraction of impacted mandibular third molars. Indexes including operation time, intraoperative anxiety, postoperative pain and limitation of mouth opening were recorded and analyzed with SPSS 22.0 software package. RESULTS: Patients with transverse method experienced more time in operation [(17.41±3.72) vs (15.22±2.53) min], with less intraoperative anxiety (P<0.05). There was no significant difference in postoperative pain and limitation of mouth opening(P>0.05) between two methods. CONCLUSIONS: Transverse T-shaped method can alleviate intraoperative anxiety, while longitudinal method is more conducive to shortening operation time. References | Related Articles | Metrics

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Efficiency of diode laser-assisted methods in direct pulp capping of carious teeth ZHANG Bin, YANG Bei-bei, GAO Zhen-yan, LI Li, AN Hong 2020, 29 (5):  554-556.  doi: 10.19439/j.sjos.2020.05.021 Abstract ( 737 )   PDF (2403KB) ( 396 )   PURPOSE: To explore the efficiency of diode laser-assisted methods in direct pulp capping of carious teeth. METHODS: A total of 100 carious teeth were randomly divided into experimental group and control group, 50 in each group. Patients in the control group were treated with conventional treatment, while in the experimental group, 808 nm, 1.5 W laser with fiber diameter of 320 μm was used on the exposure site to control hemorrhage, and 1W laser was used to decontaminate the cavity. SPSS 19.0 software package was used for data analysis. RESULTS: Of 50 patients in the experimental group, three teeth were lost to follow-up, the total effective rate was 89.4%. Of 50 patients in the control group, five teeth were lost to follow-up, the total effective rate was 73.3%. The difference between the two groups was statistically significant (P<0.05). CONCLUSIONS: Laser-assisted procedure in carious exposures is more effective than conventional treatment in pulp-capping therapy, which is worthy of wide application. References | Related Articles | Metrics

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Clinical effect of Nd:YAP laser in periodontal regeneration surgery SUN Qing, GAO Xiao-fang 2020, 29 (5):  557-560.  doi: 10.19439/j.sjos.2020.05.022 Abstract ( 467 )   PDF (2837KB) ( 211 )   PURPOSE: To evaluate the clinical effect of Nd:YAP laser in periodontal regeneration surgery. METHODS: Four weeks after primary periodontal treatment, 48 patients, 60 teeth with bone defect and probing depth(PD) ≥6 mm, bleeding on probing (BOP)(+), were randomly divided into two groups. Patients in the experimental group were treated with Nd:YAP laser combined with periodontal regeneration surgery, while patients in the control group were treated with conventional periodontal regeneration surgery alone. Visual analogue scale(VAS) score was used to evaluate the pain degree of patients 24 hours and 3 days after surgery. The probing depth(PD) and clinical attachment loss(CAL) were examined before and 6 months after surgery, and preoperative and postoperative X-ray images of the two groups were observed and compared. SPSS 26.0 software package was used for statistical analysis. RESULTS: Twenty-four hours and 3 days after surgery, the pain in the experimental group was significantly less than that in the control group (P<0.001), and PD and CAL levels in the two groups were significantly lower 6 months after surgery than before surgery (P<0.001). There was no significant difference in PD and CAL between the two groups before surgery, and the difference was statistically significant 6 months after surgery(P<0.001). X-ray images showed different degrees of new bone formation in alveolar bone defects in the two groups 6 months after surgery. CONCLUSIONS: The application of Nd:YAP laser in periodontal regeneration surgery can reduce postoperative pain and improve the surgical efficacy. References | Related Articles | Metrics