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Objetivo: Com base nas características biológicas e físico-químicas do agregado de trióxido mineral (MTA), este seria o material mais adequado para a obturação do canal radicular. No entanto, esse material apresenta baixo escoamento e, consequentemente, difícil manipulação. O MTA Fillapex (MTA-F) foi criado na tentativa de combinar as propriedades físico-químicas do cimento endodôntico com as propriedades biológicas do MTA. No entanto, os estudos sobre as características biológicas do MTA-F ainda são controversos. Dessa forma, este estudo teve como objetivo analisar in vitro a citotoxicidade do MTA-F. Materiais e Métodos: fi broblastos gengivais foram cultivados em Dulbecco’s modifi ed Eagle Medium (DMEM) e submetidos ao meio de cultura condicionado pelo MTA ou MTA-F. Esse meio condicionado continha substâncias liberadas pelos cimentos endodônticos. Células cultivadas em meio fresco serviram como controle positivo. A viabilidade celular foi avaliada por ensaio do MTT após 1, 3, 5 e 7 dias. Os dados obtidos foram comparados por análise de variância (ANOVA) seguida pelo teste de Tukey (p < 0,05). Resultados: As células submetidas ao meio condicionado pelo MTA apresentaram curva de crescimento celular semelhante à das células do grupo controle. Para o grupo MTA-F, não houve crescimento celular e foi observado um número de células viáveis signifi cativamente menor do que o dos demais grupos durante todo o experimento. Conclusão: Substâncias liberadas a partir de MTA-F não permitiram o crescimento celular, mostrando que esse cimento endodôntico à base de MTA é altamente citotóxico. A característica de biocompatibilidade do MTA pode ser perdida com o MTA-F e comprometer o sucesso do tratamento endodôntico.

Aim: Based on its biological and physicochemical characteristics, mineral trioxide aggregate (MTA) could be considered the most appropriate material for root canal obturation; nevertheless, handling of MTA is not easy. The MTA Fillapex (MTA-F) was created in an attempt to combine the physicochemical properties of a root canal sealer with the biological properties of MTA. However, the studies on the biological characteristics of MTA-F are still controversial. Thus, this study aimed to analyze the cytotoxicity of MTA-F. Materials and Methods: Cultured human gingival fi broblasts were grown in Dulbecco’s modifi ed Eagle Medium (DMEM) and submitted to a cell culture medium conditioned by MTA or MTA-F. The conditioned medium contained substances leached from the root canal sealers. Cells grown on a fresh medium served as a positive control. Cell viability was assessed by MTT assay at 1, 3, 5 and 7 days. Data was compared by ANOVA followed by Tukey’s test (p < 0.05). Results: Cells submitted to media conditioned by MTA presented a cell growth curve similar to that of the control cells. For the MTA-F group, cell growth was not observed and cell viability was signifi cantly lower than for the other groups during the entire experiment. Conclusion: Substances leached from MTA-F did not allow cell growth, indicating that this MTA-based root sealer is highly cytotoxic. The biocompatibility characteristic of MTA can be lost with MTA-F, and may compromise the endodontic treatment outcome.

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BACKGROUND: Mesenchymal stem cells have prominent immune modulatory properties, which may have clinical applications; however their major source, bone marrow, is of limited availability. On the other hand, mesenchymal stem cells derived from human exfoliated deciduous teeth (SHEDs) are readily accessible, but their immune regulatory properties have not been completely investigated. This study was designed, therefore, to evaluate the SHEDs influence on DCs differentiation, maturation, ability to activate T cells and to expand CD4(+)Foxp3(+) T cells. METHODOLOGY/PRINCIPAL FINDINGS: The experiments were based in cellular co-culture during differentiation and maturation of monocyte derived-DCs (moDCs), with, or not, presence of SHEDs. After co-culture with SHEDs, (moDCs) presented lower expression of BDCA-1 and CD11c, in comparison to DC cultivated without SHEDs. CD40, CD80, CD83 and CD86 levels were also decreased in mature DCs (mDCs) after co-cultivation with SHEDs. To assess the ability of SHEDs-exposed moDCs to modulate T cell responses, the former were separated from SHEDs, and co-cultured with peripheral blood lymphocytes. After 5 days, the proliferation of CD4(+) and CD8(+) T cells was evaluated and found to be lower than that induced by moDCs cultivated without SHEDs. In addition, an increase in the proportion of CD4(+)Foxp3(+)IL-10(+) T cells was observed among cells stimulated by mature moDCs that were previously cultivated with SHEDs. Soluble factors released during co-cultures also showed a reduction in the pro-inflammatory cytokines (IL-2, TNF-α and IFN-γ), and an increase in the anti-inflammatory molecule IL-10. CONCLUSION/SIGNIFICANCE: This study shows that SHEDs induce an immune regulatory phenotype in moDCs cells, evidenced by changes in maturation and differentiation rates, inhibition of lymphocyte stimulation and ability to expand CD4(+)Foxp3(+) T cells. Further characterization and validation of this phenomenon could support the use of SHEDs, directly or indirectly for immune modulation in the clinical practice.

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Stem cells, both embryonic and adult, due to the potential for application in tissue regeneration have been the target of interest to the world scientific community. In fact, stem cells can be considered revolutionary in the field of medicine, especially in the treatment of a wide range of human diseases. However, caution is needed in the clinical application of such cells and this is an issue that demands more studies. This paper will discuss some controversial issues of importance for achieving cell therapy safety and success. Particularly, the following aspects of stem cell biology will be presented: methods for stem cells culture, teratogenic or tumorigenic potential, cellular dose, proliferation, senescence, karyotyping, and immunosuppressive activity.

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Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells.

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Little is known about the histogenesis of the odontogenic myxoma (OM). Dental pulp stem cells could be candidate precursors of OM because both OM and the dental pulp share the same embryological origin: the dental papilla. For the purpose of comparing OM and stem cells, this study analyzed the expression of two proteins related to OM invasiveness (MMP-2 and hyaluronic acid) in human immature dental pulp stem cells (hIDPSCs). Three lineages of hIDPSCs from deciduous and permanent teeth were used in this study. Immunofluorescence revealed positive reactions for MMP-2 and hyaluronic acid (HA) in all hIDPSCs. MMP-2 appeared as dots throughout the cytoplasm, whereas HA appeared either as diffuse and irregular dots or as short fibrils throughout the cytoplasm and outside the cell bodies. The gene expression profile of each cell lineage was evaluated using RT-PCR analysis, and HA was expressed more intensively than MMP-2. HA expression was similar among the three hIDPSCs lineages, whereas MMP-2 expression was higher in DL-1 than in the other cell lines. The expression of proteins related to OM invasiveness in hIDPSCs could indicate that OM originates from dental pulp stem cells.

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Aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. The bleaching agent (35 % hydrogen peroxide) was activated by halogen light; LED (Light Emitting Diode) or LED, followed by laser phototherapy (LPT) (λ = 780 nm; 3 J/cm²). After the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. The teeth were diaphanized and photographed. The amount of blue stain content of each dental pulp was quantified using a computer imaging program. The data was statistically compared (p < 0.05). The results showed a significant higher (p < 0.01) dye content in the groups bleached with halogen light, compared with the control, LED and LED plus LPT groups. Thus, tooth bleaching activated by LED or LED plus LPT induces lesser resulted in increased vascular permeability than halogen light.

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Stem cells are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized celltypes. An important source of adult stem cells is the dental pulp. In dentistry, regenerative strategies are ofimportance because of hard dental tissue damage especially as result of caries lesions, trauma, or iatrogenicprocedures. The regeneration of dental tissues relies on the ability of stem cells to produce extracellular (ECM) proteins encountered in the dental pulp tissue.Thus, the aim of this study was to analyze the expression and distribution of proteins encountered in dental pulpECM (type I collagen, fibronectin, and tenascin) in stem cells. Human immature dental pulp stem cells (hIDPSCs) from deciduous (DL-1 and DL-4 cell lines) and permanent (DL-2) teeth were used. The distribution of ECM proteins was observed using theimmunofluorescence technique. The gene expression profile was evaluated using reverse transcription polymerase chain reaction (RT-PCR) analysis. Positive reactions for all ECM proteins were observed independently of the hIDPSCs analyzed. Type I collagenappeared less evident in DL-2 than in other hIDPSCs. Fibronectin and tenascin were less clear in DL-4. TheRT-PCR reactions showed that type I collagen was lesser expressed in the DL-2 cells, whereas fibronectin and tenascinwere similarly expressed in all hIDPSCs. The distribution and expression of ECM proteins differ among the hIDPSCs. These differences seemed to be related to the donor tooth conditions (deciduous or permanent, retained or erupted, and degree of root reabsorption).

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The effects of laser phototherapy on the release of growth factors by human gingival fibroblasts were studied in vitro. Cells from a primary culture were irradiated twice (6 h interval), with continuous diode laser [gallium-aluminum-arsenium (GaAlAs), 780 nm, or indium-gallium-aluminum-phosphide (InGaAlP),_660 nm] in punctual and contact mode, 40 mW, spot size 0.042 cm(2), 3 J/cm(2) and 5 J/cm(2) (3 s and 5 s, respectively). Positive [10% fetal bovine serum (FBS)] and negative (1%FBS) controls were not irradiated. Production of keratinocyte growth factor (KGF) and basic fibroblast growth factor (bFGF) was quantified by enzyme-linked immunosorbent assay (ELISA). The data were statistically compared by analysis of variance (ANOVA) followed by Tukey's test (P

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Este trabalho teve como objetivo avaliar o nível de conhecimento de uma população sobre o câncer oral para o estabelecimento de estratégias eficientes de prevenção e tratamento desta doença, sendo realizadodurante duas campanhas de prevenção de câncer oral, onde setecentos e trinta e uma pessoas (731)foram examinadas, preencheram um questionário, receberam orientação sobre o auto-exame e noções básicas sobre o câncer oral. O questionário continha questões referentes à causa, sintomatologia, doençaprévia e hábitos prejudiciais relacionados ao câncer oral. Entre os participantes 43% eram homens e 57%mulheres, 24% fumantes e 21% consumidores de bebidas alcoólicas, 87% declararam ter conhecimentoda existência dessa doença, 12% já tiveram familiar com câncer oral, 57% acreditam que o câncer oralcausa dor, 44% acreditam que o fumo e 23% que o consumo de álcool está ligado à etiologia da doença. Acampanha atingiu uma população com bom conhecimento sobre o câncer e com baixo risco para o cânceroral, assim as formas de abordagem e de divulgação desses tipos de campanhas devem ser alteradas pararealmente contemplar as pessoas pertencentes ao grupo de risco para o câncer oral, que são os homenscom mais de 40 anos, fumantes, etilistas crônicos e pessoas expostas à radiação solar de maneira contínuae freqüente. Conclui-se que a verificação do nível de conhecimento sobre o câncer oral nas diferentes populaçõesé importante para que estratégias de prevenção e diagnóstico sejam estabelecidas de acordo com operfil de cada grupo.

The present work had the objective to find out the population's knowledge about oral cancer to establishefficient strategies of prevention and treatment of this disease, it was realized during two preventscampaigns of oral cancer, where seven hundred and thirty one people (731) were examined, filled a questionnaire,received orientation about the auto-exam and basic notion about oral cancer. The questionnaireincluded questions about the etiology, symptoms, previous disease and habits related to oral cancer. In thiswork 43% were men and 57% women, 24% smokers and 21% consumer of alcoholic drinks, 87% know theexisting of the disease, 12% have already had parents with oral cancer, 57% believe that the oral cancer causepain, 44% believe that tobacco and 23% that the use of alcohol is related with the etiology of the disease.The campaign achieved a population with good knowledge about cancer and with low risk to oral cancer, likethis the form of achieve and divulgation of these kinds of campaign should be modified to really achieve depeople who are the risk group, like men with more than 40 years old, smoker, alcohol's consumer and peopleexposed frequently and continuous to solar radiation. It was concluded that the level of knowledge about oralcancer in different populations is important to that strategies for the prevention and diagnosis are established according to the profile of each group.

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Células-tronco adultas podem ser isoladas de vários tecidos, dentre eles a polpa dentária humana, tecido originado na papila dentária do dente em desenvolvimento. Estas linhagens multipotentes podem ser estudadas sob vários aspectos, como na elucidação da histogênese de tumores. O objetivo deste estudo foi inferir a histogênese do mixoma odontogênico, neoplasia odontogênica benigna, analisando a expressão de proteínas da matriz extracelular (MEC) e de metaloproteinases da matriz (MMPs) em células-tronco adultas de polpa dentária humana. Três linhagens diferentes de células-tronco originadas de polpas dentárias humanas IDPSCs (DL-1, DL-2 e DL4) foram utilizadas. As proteínas analisadas foram as mesmas expressas na neoplasia: vimentina, colágeno tipo I, fibronectina, tenascina, ácido hialurônico e MMPs (MMP-1, MMP-2 e MMP-9). Imunofluorescência e ensaios enzimáticos foram utilizados para analisar a presença de proteínas nas células cultivadas e no meio de cultura condicionado por estas células, respectivamente. Todas as linhagens celulares expressaram a vimentina e nenhuma expressou o ácido hialurônico. A linhagem celular DL-1 expressou todas as outras proteínas da matriz extracelular estudadas, enquanto que na linhagem DL-2 apenas não foi observada a expressão do colágeno tipo I. Fibronectina e tenascina não foram observados na linhagem DL-4. Todas as linhagens expressaram todas as MMPs, sendo...

Adult stem cells can be isolated from different tissues including the human dental pulp, a structure originated from the dental papillae. These cell lineages are of importance in a series of studies, as the analysis of tumors histogenesis. The aim of this study was to infer the histogenesis of odontogenic myxoma, a benign odontogenic neoplasia by analyzing the ECM and MMPs molecules expressed in human dental pulp stem cells. Three different lineages of immature dental pulp stem cells (IDPSCs) (DL-1, DL-2 and DL-4) were used. The proteins searched were those expressed by the tumoral cells: vimentin, type I collagen, fibronectin, tenascin and hialuronic acid (HA) and the matrix metalloproteinases (MMP-1, MMP-2 and MMP-9). Immunofluorecence and enzymatic assays were used for analyzing the presence of the proteins in the cells and in the culture media conditioned by the cells, respectively. All the lineages expressed vimentin; however none expressed HA. DL-1 lineage expressed all the other ECM proteins, and the expression of type I collagen was not observed in the DL-2 lineage. Fibronectin and tenascin were not observed in the DL-4 lineage. All the lineages expressed all the MMPs. The release of MMP-2 from all cell lineages was significantly higher than those of all other MMPs. Based on the conditions of this study its possible to conclude that the overall expression of MEC proteins and MMPs in the lineages of human dental pulp stem cells...

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