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Objective To compare the reprogramming effects and biological characteristics of two types of human odontogen-ic induced pluripotent stem cells(iPSCs).Methods Human dental pulp stem cells(DPSCs)and stem cells from apical papilla (SCAP)were isolated and primarily cultured.The Sendai reprogramming system was utilized to induce DPSCs and SCAP into iP-SCs.The morphology,reprogramming efficiency,reprogramming and time were compared between human DPSCs-iPSCs and SCAP-iPSCs.The SeV and exogenous transcriptional gene expression were detected by RT-PCR.Results Human DPSCs and SCAP were reprogrammed as iPSCs with classical ES-like clonal morphology.The reprogramming efficiencies were(0.68 ± 0.02)% and(0.7 ± 0.01)% respectively,the difference was not statistically significant(P>0.05).The reprogramming time was(26.0 ± 2.1)d and (27.0 ± 1.4)d respectively,the difference was not statistically significant(P>0.05).The RT-PCR results showed that no expres-sion of exogenous virus or transcriptional gene sequence in both iPSCs.Conclusion Human DPSCs and SCAP can be reprogrammed as virus-free and transgene-free iPSCs,which are the ideal sources of iPSCs.
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Objective:To study the effects of 3 extracts from Chinese gall on the growth and metabolism of 6 kinds of oral bacteria.Methods:Through a series of extraction and purification,3 active monomer,gallnut extract gallic acid,methyl gallate and gallic acid ethyl ester were selected.Streptococcus mutansUA159(UA159),Actinomyces viscosus (Av),Porphyromonas gingivalis (Pg),Enterococcus faecalis (Ef),Fusobacterium nucleatum(Fn) and Candida albicans (Ca) were treated by the extracts respectively,The growth and metabolism of the becteria were studied by liguid dilution method.Results:The MIC(mg/ml) of Gallic acid anainst the bacteria was 2.5-5,methyl gallate 2.0-4.0 and gallic acid ethyl ester 1.25-2.5.The extracts at 1 mg/ml could inhibit the growth,acid production and extracellular polysaccharides of the 6 oral pathogens.And ethyl gallate showed the strongest effects.Conclusion:Gallic acid and methyl gallate and ethyl gallate at low concentration may inhibit the growth,acid metabolism and glucose metabolism of oral bacteria.
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Objective To comparatively study the characteristics of 3 kinds of culture substrates of human odontogenic induced pluripotent stem cells(iPSCs).Methods The human odontogenic iPSCs were cultured by 3 kinds of substrates:mouse embryonic fibroblasts(MEF),matrigel and recombinant human vitronectin(VTN-N).The iPSCs growth situation was compared among three groups.Results The preparation time of these 3 kinds of substrates was 14,3,1 hlespectively,and,the difference was statistically significant (P＜0.05).The iPSCs reprogramming time was (30± 1.6),(26 ± 2.1),(27 ± 1.4) d,lespectively,wht that in the MEF group significantly higer than in other two groups (P＜0.05).The reprogramming efficiencies were 0.3 ％ ± 0.03 ％,0.56 ％ ± 0.08 ％,0.7 ％ ± 0.02 ％ respectively (P＜ 0.05).Three kinds of substrate could better support iPSCs growth and make them to maintain un-differentiation status.Conclusion with no heterologous animal components,and the adrantaga of simple pleparation,oonfrollable standard and shorter gramming time is easy to prepare,the standard is controllable and the reprogramming time is shorter,which is an ideal substrate for supporting iPSCs growth.
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Objective To compare the growth characteristics,proliferation and osteo/odontogenic differentiation capability of stem cells from human dental pulp (dental pulp stem cells,DPSCs) and apical papilla (stem cells from apical papilla,SCAP) in vitro.Methods Human dental pulp and apical papilla tissues were separated from impacted third molars of young healthy donors at the age of root development and digested by collagenase type Ⅰ and dispase type Ⅱ to derive primitive DPSCs and SCAP.Cells were then induced for osteo/odontongenic differentiation by medium containing β-glycerophosphate,dexamethasone and KH2PO4.Flow cytometry was utilized to test the expression of specific markers of stem cells,including CD24,CD34,CD45,CD90,CD105,CD146,STRO-1 and OCT-4.AR-S was used to display the mineralization structure and RT-PCR was applied to analyze the expression of bone sialoprotein (BSP),osteocalcin (OCN) and dentine sialophosphoprotein (DSPP).Results Both DPSCs and SCAP were positive for CD90,CD105,CD146,STRO-1 and OCT-4,in percentages varying according to cell type,without expression of CD34 or CD45.Only SCAP expressed CD24 positively.Both cells formed organized mineralization structure after 2 weeks of induction in time-dependent manner,with more mineralization by SCAP and expressed differentiation markers,including BSP,OCN and DSPP.Conclusion Human DPSCs and SCAP possess the characteristics of MSCs and could be differentiated into odontonblast-like cells in vitro.Both cells are approachable stem cell sources for dental tissue engineering.
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Objective To comparatively study the features of two reprogramming systems of induced pluripotent stem cells (iPSCs)from human dental origin.Methods Two kinds of reprogramming system,i.e.STEMCCA lentivirus /feed layer and Sen-dai virus /matrigel were used to induce human stem cells from apical papilla(SCAP)into iPSCs,respectively.The induction efficien-cies,workload of generating iPSCs,aneuploidy karyotype ratio,complexities of eliminating exogenous transcription factors and spe-cific markers expression were compared between these two systems.Results The STEMCCA reprogramming system required to prepare the feeder cell MEF.The reprogramming efficiency was 0.1%.Transcription gene-free iPSCs cells were obtained by the Cre-loxp enzyme digestion technique at the later stage.Sendai virus reprogramming system was feeder-free and the preparation of matrigel was quite simple with unified standard.The reprogramming efficiency was 0.7%,which was much higher than that of STEMCCA system(P <0.05).The exogenous virus and transgenes could be gradually eliminated after several passages of natural subclone.Conclusion The Sendai virus/matrigle reprogramming system is much more applicable for the induction of iPSCs from dental origin than the STEMCCA system.
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Caries is one of the most common chronic progressive oral diseases. TCM medicinal herbs have many advantages compared with traditional dental drugs for caries (such as fluoride). In recent years, cariogenic TCM medicinal herbs have attracted the attention of many domestic and foreign scholars. Caries is not caused by a single factor. The development of caries is closely related to bacterial biofilms that are formed by streptococcus mutans, streptococcus sanguis, actinomyces inside, actinomyces and lactobacillus. Therefore, this article took a brief overview of TCM medicinal herbs and their active ingredients that inhibit the bacterial biofilms.
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Objective To investigate the changes of serum C reactive protein(CRP) ,tumor necrosis factor alpha(TNF-alpha) and interleukin-17(IL-17) by minocycline ointment on the basis of conventional therapy in the treatment of aggressive periodontitis (AgP) .Methods All 45 cases of AgP patients were randomly divided into two groups ,23 cases in the therapeutic group ,were per-formed scaling and root planning plus local minocycline hydrochloride Ointment medication;22 cases in the control group ,were trea-ted by scaling and root planing only .All aggressive periodontitis patients were detected the serum CRP ,TNF-alpha and IL-17 levels before and after treatment ,and compared with normal controls .Results The serum levels of CRP ,TNF-αand IL-17 in normal hu-man were lower than those of AgP patients before and after treatment(P<0 .05) .After 3 months treatment ,the serum levels of CRP ,TNF-αand IL-17 in AgP patients were significantly lower than those before treatment(P<0 .05) .Conclusion The effect of minocycline on the basis of conventional therapy in the treatment of AgP patient is remarkable ,which can improve the serum level of CRP ,TNF-alpha and IL-17 .
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Objective To investigate the incidence of C-shaped root canal systems in mandibular second perma?nent molar of patients in the First People’s Hospital of Yunnan Province, and compare the success rate between one-and two-visit root canal treatment. Methods Two hundred and sixty mandibular second molars were recruited from the pa?tients in the department of endodontics of our hospital, and teeth with C-shaped root canal were categorized by using radio?graphic classification criteria and the modified Melton’s method. Teeth with C-shaped root canal systems were then random?ly divided into two groups to receive one-or two-visit root canal treatment, and success rates of 6-month post-operation were compared between two groups. Results Eighty out of 260 mandibular second molars exhibited C-shaped canals (30.77%). Radiographic examination showed that 25 teeth belonged to typeⅠ(31.25%), 32 teeth typeⅡ(40.00%) and 23 teeth typeⅢ(28.75%) in two groups. As for modified Melton’s method, the incidence rates were 21.25%, 48.75%, 16.25%and 13.75% for C1,C2,C3a and C3b, respectively, while C4 was not found. The success rates were 78.94% (30/38) and 81.08%(30/37) for A group and B group, respectively, with no statistically significant difference between two groups ( 78.94 vs 81.08, P>0.05). Conclusion Results indicate a frequent incidence of C-shaped root canal system of mandibular per?manent second molars in our hospital. One-visit root canal treatment is an effective way for treating C-shaped canals in man?dibular permanent second molar.
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Objective To conduct one-visit or multi-visit root canal treatment for infected root canals ,to observe and analyze the postoperative pain and the periapical healing status and to evaluate the clinical application of one -visit root canal therapy .Meth-ods 80 teeth diagnosed as chronic apical periodontitis were recruited .40 cases were included in one-visit root canal treatment group and the other 40 cases in multi-visit group with calcium hydroxide as an interapoinment medicament .Main clinical assessments in-cluded postoperative pain ,postoperative X ray and 6 months′periapical healing response .Results There there was no statistically significant difference between the groups regarding postoperative pain (one-visit group 37 .5% ,multi-visit 35 .0% ,P>0 .05) and 6 months′periapical healing response(one-visit group 81 .6% ,multi-visit 80 .6% ,P>0 .05) .Conclusion One-visit root canal treat-ment has the same clinical effect(postoperative pain and periapical healing ) as multi-visit on infected root canals and has the clinical feasibility of routine use .