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CONTEXT: A novel root-filling material based on the incorporation of ultrafine alkaline bioactive glass particles (bioactive gutta-percha, [BGP]) was developed to work without sealer. AIM: In the present study, the objective was to verify the in vitro biological response to this material by assessing its cytocompatibility. MATERIALS AND METHODS: Prototypes of BGP were compared to conventional gutta-percha (GP), dense polystyrene beads as a negative control and fragments of latex as a positive control. Extracts of each material were prepared according to ISO 10993-5:2009, and human osteoblast-like cells in primary culture were exposed to all extracts for 24 h. Cell viability was assayed sequentially for three different parameters: mitochondrial activity, membrane integrity, and cell density. STATISTICAL ANALYSIS USED: Nonparametric analysis (using Kruskal-Wallis test combined with post hoc Dunn's test) was performed for comparison among groups, with significance established at 5%. RESULTS: BGP reduced mitochondrial activity to 62% of control, but presented no toxicity on membrane integrity and proliferation assays. BGP effect on metabolism was dose-dependent and reduced to acceptable levels with dilution. CONCLUSION: The novel GP material presented slight dose-dependent effects on cell metabolism but did not affect cell survival.
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Since the way that human bone cells behave on contact with different surfaces topographies seems to be crucial to osseointegration, the aim of the present study is to evaluate the participation of some micro- and nanosized features of Ti surfaces in the short-term response of primary human osteoblast-like cells (HOC). Surfaces were prepared as ground (G-Ti), hydrofluoric acid etched (HF-Ti), and sandblasted/HF-etched (SLA-Ti), and analyzed using both three-dimensional (3D) profilometer and atomic force microscope (AFM). Cell morphology was assessed using scanning electron microscopy (SEM) after 4 and 24 h in culture. Cell viability, adhesion, and spreading were also evaluated 4 and 24 h after seeding over each surface. Data were compared by analysis of variance (ANOVA) complemented by Duncan test. Cell morphology, cell counting, and membrane integrity (Neutral Red, NR) were not affected by surface treatment at any time. However, HF-Ti presented the smallest surface area and did not increase tetrazolium hydroxide (XTT) reduction from 4 to 24 h. On the other hand, a higher level of spreading was only found on the rougher and isotropic SLA-Ti at 4 h. In conclusion, although all evaluated Ti surfaces allowed HOC short-term adhesion, the finer topography introduced by HF as single treatment did not favor HOC mitochondrial activity and spreading. The rougher and more complex SLA surface seems to provide a better substrate for HOC short-term response.
Assuntos
Nanopartículas , Osteoblastos/fisiologia , Titânio , Adesão Celular , Forma Celular , Sobrevivência Celular , Humanos , Microscopia Eletrônica de Varredura , Osteoblastos/ultraestruturaRESUMO
This work evaluates the suitability of biphasic calcium phosphate (BCP) granules (ß-TCP/HA 70:30) as potential carriers for cell-guided bone therapy. The BCP granules were obtained by synthesis in the presence of wax, thermal treatment, crushing and sieving and characterized by scanning electron microscopy (SEM), X-ray diffraction and Fourier transform infrared spectroscopy. The cytocompatibility of the BCP granules was confirmed by a multiparametric cytotoxicity assay. SEM analysis showed human bone cell adhesion and migration after seeding onto the material. Rat subcutaneous xenogeneic grafting of granules associated to human bone cells revealed a more accentuated moderate chronic inflammatory infiltrate, without signs of a strong xenoreactivity. Histomorphometrical analysis of bone repair of defects in rat skulls (∅ = 5 mm) has shown that bone cell associated-BCP and autograft promoted a two- and threefold increase, respectively, on new bone formation after 45 days, as compared to BCP alone and blood clot. The increase in bone repair supports the suitability the biocompatible (70:30) BCP granules as injectable and mouldable scaffolds for human cells in bone bioengineering.
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Remodelação Óssea , Osso e Ossos/citologia , Fosfatos de Cálcio/química , Células Cultivadas , Humanos , Microscopia Eletrônica de VarreduraRESUMO
Ainda são muito raras as informações sobre a resposta de osteoblastos humanos ao Ceramicrete (CC), um material proposto para ser usado como cimento reparador que apresenta características bastante promissoras. Assim, o objetivo do presente estudo foi verificar o grau de citocompatibilidade do CC em culturas primárias de osteoblastos humanos. Para isso, foi utilizado um modelo experimental baseado na quantidade de material usado em uma retro-obturação, criando condições mais próximas a situação clínica real. Retrocavidades obturadas com CC foram colocados em poços de cultura contendo meio de cultura (α-MEM), por 24h (n=4). Meios de cultura contendo dentes retro-obturados com ProRoot MTA e OZE foram usados como controle negativo e positivo, respectivamente. Todos os meios foram armazenados. Posteriormente, foram cultivados osteoblastos humanos (2 x 104 células/amostra), por 24h, em poços com os meios armazenados dos 3 materiais. Foi avaliada a citocompatibilidade utilizando um Kit específico (Cytotox Kit, Xenometrix, Alemanha), que possibilita o estudo de 3 parâmetros (XTT, NR e CVDE) utilizando a mesma amostra. Foi encontrada uma diferença estatisticamente significativa entre os 3 materiais para todos os 3 parâmetros avaliados (ANOVA, p< 0,05). O CC e o MTA foram sempre estatisticamente superiores ao OZE (Duncan, p<0,05). Entretanto, não foram encontradas diferenças entre os 2 cimentos reparadores, CC e MTA (Duncan, p> 0,05). Portanto, pode-se concluir que o Ceramicrete expressa um padrão de citocompatibilidade similar a do MTA, em cultura primária de osteoblastos humanos, quando usado como material retro-obturador.
Ceramicrete is an endodontic material with very promising characteristics. However, information about the response of human osteoblasts to CC is very rare. So, the purpose of this study was to assess the cytocompatibility of CC in primary cultures of human osteoblasts. For this, we used a modelo f retro-obturation, creating conditions close to real clinical situation. The apical portions of canines were retro-obturated with CC or control materials. The, the teeth were placed in Wells containing culture médium (α-MEM) for 24h (n=4). ProRoot MTA and ZOE were used as negative and positive controls, respectively. All media were stored. Subsequently, human osteoblasts were cultured (2x104 cells) for 24 h in Wells with the stored medium. The cytocompatibility was evaluated using a specific kit (Cytotoxic, Xenometrix, Germany), which enables the study of three parameters of cell viability using the same sample (CTT, NR and CVDE). It was found significant difference among the three materials Fo all parameters (ANOVA, p> 0.05). The CC and the MTA were always statistically superior to ZOE (Duncan, p> 0.05). However, no differentes were found between the two cements, CC and MTA (Duncan, p> 0.05). It can be concluded that CC is an endodontic cement as cytocompatible as MTA when used as a retro-obturation material in primary cultures of human osteoblasts.
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Cimentos Dentários , Osteoblastos , Obturação RetrógradaRESUMO
O objetivo deste trabalho é avaliar a citotoxicidade dos fios ortodônticos estéticos feitos à base de resina polimérica reforçada com fibras de vidro, por três diferentes parâmetros de viabilidade celular. Foram preparados, de acordo com normas internacionais, extratos de amostras do fio Optis® Preformed Archwire intactos ou multiseccionados (em seções de 10 mm) e, como referência, fios de aço inoxidável do mesmo fabricante. Fenol a 2% e poliestireno denso foram utilizados como controle negativo e positivo respectivamente. Células de fibroblastos de camundongo da linhagem Balb/c-3T3 foram expostas por 24 horas a esses extratos, e a viabilidade celular foi identificada por três parâmetros: atividade mitocondrial, a partir do método do XTT, integridade membranar, pela captação do corante vermelho neutro e densidade celular, por meio do teste de exclusão do corante cristal violeta. Os extratos dos fios (aço inoxidável e fio em resina reforçada por fibra de vidro) foram compatíveis com altos índices de viabilidade celular medido através dos três diferentes parâmetros, sem diferenças estatísticas significativas entre os grupos. O processamento do fio estético em pequenas secções não alterou sua biocompatibilidade medida pelos mesmos métodos, indicando não haver diferença de toxicidade entre sua face externa de resina e seu interior reforçado em fibra de vidro. De acordo com os parâmetros avaliados, o fio estético não apresentou citotoxicidade, similar ao aço inoxidável já em largo uso ortodôntico. No entanto, novos parâmetros devem ser investigados para validá-lo, tanto com relação a aspectos biológicos como a aspectos físicos mais relacionados à sua eficiência na ortodontia.
The purpose of this paper is evaluate the cytotoxicity of orthodontic archwires on polymeric resin reinforced with glass fiber, by three different cell viability parameters. According to international standards, extract samples of Optis® Preformed Archwire, both intact and sectioned into 10 mm pieces and, as reference, of stainless steel archwires, form the same manufacturer. 2% phenol and dense polystyrene were employed as a positive and negative control respectively. Balb/c-3T3 mouse fibroblasts were exposed by 24 hours to the extracts and cell viability was assayed by three parameters: mitochondrial activity (XTT), membrane integrity, measured by Neutral red uptake, and cell density as measured by the Violet Crystal dye exclusion test. Both archwires (stainless steel and fiber glass reinforced resin) were consisted with high levels of cell viability as measured by the three tests, without significative statistical differences among groups. Wire processing by cutting into little sections did not change biocompatibility as measured by the same methods, suggesting that there is no difference between the resin external face and the internal glass fiber reinforced interior. According to the evaluated parameters, the esthetic archwire does not presented cytotoxicity levels, similar to those obtained with a material widely employed in orthodontics. However, other parameters should be investigated in order to validate this material, both related to biological aspects, as well as physical characteristics more associated to its efficacy in orthodontics.
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Estética Dentária , Fios Ortodônticos , OrtodontiaRESUMO
INTRODUCTION: The aim of this study was to evaluate and compare the cytotoxic effects of BioAggregate (Innovative BioCaramix Inc, Vancouver, BC, Canada), a novel bioceramic nanoparticulate cement, on human mesenchymal cells. White Pro-Root MTA (Dentsply, Tulsa Dental, Tulsa, OK) was used as a reference for comparison. METHODS: Fifty-six human maxillary incisor teeth were submitted to a step-back flaring technique and prepared for cytotoxicity assay in an in situ root-end filling experimental model. After retro filling, each root containing MTA, BioAggregate, or empty root canals (control) was exposed to culture media for 24, 48, or 72 hours, providing several extraction media. Mesenchymal cells were incubated with each extract medium for 24 hours, and toxicity was evaluated by three different parameters of cell survival and integrity on the same sample: XTT, neutral red, and crystal violet dye elution. RESULTS: No statistically significant differences between MTA and BioAggregate were found in all the experimental periods (p > 0.05). CONCLUSION: DiaRoot BioAggregate displayed in vitro compatibility similar to MTA.
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Materiais Biocompatíveis/toxicidade , Cerâmica/química , Cimentos Dentários/toxicidade , Mesoderma/efeitos dos fármacos , Nanopartículas/química , Materiais Restauradores do Canal Radicular/toxicidade , Compostos de Alumínio/farmacologia , Compostos de Cálcio/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corantes , Meios de Cultura , Meios de Cultivo Condicionados , Combinação de Medicamentos , Humanos , Teste de Materiais , Mesoderma/citologia , Óxidos/farmacologia , Obturação Retrógrada , Silicatos/farmacologia , Sais de Tetrazólio , Tiazóis , Fatores de TempoRESUMO
In this work, the in vitro behavior of human osteoblast cells on the undulated surfaces of biphasic calcium phosphate tablets was investigated. The tablets were produced by uniaxial pressing with convex cylindrical undulations occupying only half of the surface area; the other half was flat. Chemical and physical characterization was performed by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). XRD and FTIR analyses revealed the presence of hydroxyapatite (HA) and alpha-tricalcium phosphate (alpha-TCP) in a well-defined ratio. Moreover, microtopography, evaluated by SEM and AFM, was similar on the flat region and on that with undulations. However, surface undulations induced different cellular arrangements, confirming the influence of the macrotopography on the cells orientation.
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Materiais Biocompatíveis/metabolismo , Fosfatos de Cálcio/metabolismo , Osteoblastos/fisiologia , Fosfatos de Cálcio/química , Temperatura Alta , Humanos , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Comprimidos/química , Comprimidos/metabolismo , Difração de Raios XRESUMO
Serum- and/or- cerebrospinal fluid (CSF) samples obtained from 190 patients suffering from chronic, progressive neurological disease were screened for the presence of human T-cell lymphotropic viruses type I (HTLV-I) and type II (HTLV-II) antibodies over a six-year period (1996 to 2001) in Belém, Pará, Brazil. Patients were of both sexes (male subjects, 52%) with ages ranging from 2 to 79 years (mean, 35.9). Overall, 15 (7.9%) subjects - of whom 12 (80%) were female adults - reacted HTLV-I/II-seropositive when screened by enzyme-linked immunosorbent assay (ELISA). Serum samples from 14 of these patients were also analyzed using a recombinant Western blot (WB) assay that yielded HTLV-I-, HTLV-II-, and HTLV-I/II- reactivities for 10 (71.4%), 3 (21.4%) and 1 (7.2%) of them, respectively. The yearly rates of HTLV-I/II antibodies ranged from 2.6% (2001) to 21.7% (2000), with progressively increasing seropositivities from 1998 to 2000. Altogether, walking difficulty (n = 5 subjects), spasticity (n = 4) and leg weakness (n = 3) accounted for 80% of symptoms recorded among the 15 patients whose sera had antibodies to HTLV-I/II as detected by ELISA. These findings provide evidence that both HTLV-I and HTLV-II play a role in the development of chronic myelopathy in Belém, Pará, Northern Brazil.
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Infecções por HTLV-I/diagnóstico , Infecções por HTLV-II/diagnóstico , Doenças do Sistema Nervoso/virologia , Paraparesia Espástica Tropical/virologia , Adolescente , Adulto , Idoso , Brasil , Criança , Pré-Escolar , Doença Crônica , Estudos de Coortes , Feminino , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Vírus Linfotrópico T Tipo 2 Humano/imunologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Amostras de soro e/ou líquido céfalo-raquidiano (LCR) foram obtidas de 190 pacientes com quadro de doença neurológica crônica e progressiva, com vistas à detecção de anticorpos para os vírus linfotrópicos humanos de células T dos tipos I (HTLV-I) e II (HTLV-II), durante um período de seis anos (1996 a 2001) em Belém, Pará, Brasil. O grupo compreendia ambos os sexos (homens, 52 por cento), com idades variando de 2 a 79 anos (média, 35,9 anos). Tomando-se os resultados como um todo, 15 (7,9 por cento) indivíduos, incluindo 12 (80 por cento) mulheres adultas, apresentaram anticorpos para HTLV-I/II a partir da triagem pelo procedimento imunoenzimático (ELISA). Soros de 14 desses pacientes também foram testados utilizando-se procedimento de Western blot (WB), alcançando-se freqüências de anticorpos para HTLV-I, HTLV-II e dupla reação (HTLV-I e HTLV-II) em 10 (71,4 por cento), 3 (21,4 por cento) e 1 (7,2 por cento) indivíduos, respectivamente. As freqüências anuais de positividade para HTLV-I/II variaram de 2,6 por cento (2001) a 21,7 por cento (2000), em escala crescente no período de 1998 a 2000. Em conjunto, dificuldade na deambulação (n = 5 pacientes), espasticidade (n = 4) e hipotonia crural compreenderam 80 por cento das manifestações clínicas registradas entre os 15 pacientes cujas amostras de soro continham anticorpos para HTLV-I/II, com base em ELISA. Tais resultados oferecem indicadores quanto a uma possível associação do HTLV-I e do HTLV-II à gênese das mielopatias crônicas em Belém, norte do Brasil.