42 research outputs found

    Evaluation of Selective Physicochemical and Biological Properties of Different Root Canal Sealers

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    Introduction: This in vitro study aimed to evaluate the chemical composition, water solubility, radiopacity, pH, electrical conductivity and cytotoxicity of four different root canal sealers. Methods and Materials: Four materials were tested including an epoxy resin-based sealer (AH-Plus), a calcium silicate-based sealer (MTA Fillapex), a calcium hydroxide-based sealer (Sealapex) and a zinc-oxide-eugenol-based sealer (Endofill). The materials were submitted to energy-dispersive x-ray microanalysis for elemental chemical composition. Solubility and radiopacity were evaluated according to ANSI/ADA. The pH and electrical conductivity were measured at different periods of time. L929 immortalized mouse fibroblast line were used for cytotoxicity evaluation. Statistical analyses were carried out using the ANOVA and Tukey’s test. Results: The main elements were found to be silicon and calcium in MTA Fillapex, calcium and bismuth in Sealapex, zirconium and tungsten in AH-Plus and zinc and bismuth in Endofill. Sealapex had the highest value for solubility (P<0.05), AH-Plus showed the highest radiopacity value (P<0.05) while MTA Fillapex had the highest pH and electrical conductivity values (P<0.05). AH-Plus showed the highest rate of cell viability (P<0.05). Conclusion: Based on the results of this in vitro study, it was possible to conclude that Endofill and Sealpex did not meet the requirements for water solubility. The tested sealers were alkaline and showed radiopacity in accordance with ANSI/ADA standards. AH-Plus showed to be less cytotoxic than other tested root canal sealers. Keywords: Biological Assay; Endodontics; Root Canal Filling Materials; Root Canal Obturatio

    Physicomechanical Properties of Tertiary Monoblock in Endodontics: A Systematic Review and Meta-analysis

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    Introduction: A systematic review and meta-analysis were conducted to evaluate the physicomechanical properties of tertiary monoblock obturation with different obturation techniques. Methods and Materials: PubMed (MEDLINE), Web of Science, Scopus, the Cochrane Library, LILACS, IBECS, and BBO were searched time. PICO question was: “In extracted human teeth (Population), does tertiary monoblock obturation (Intervention) have superior physicomechanical properties (Outcome) compared to conventional obturation systems (Comparison)?”. Statistical analyses for push-out bond strength were performed with RevMan software by comparing the mean differences of each study, with a 95% confidence interval. Inverse variance was used as statistical method, random-effects models as analysis model, and heterogeneity between studies was assessed by Cochran’s Q test and I2 statistic (P <0.05). Results: Of 2162 studies retrieved, 31 were included in this review for “Study Characteristics”. Ten studies were included in the meta-analysis. Analysis demonstrated that conventional obturation had significantly higher push-out bond strength than tertiary monoblock obturation (P <0 .01), with a mean difference of −1.00 (95% CI, −1.41 to −0.58; I2=100%). Subgroups using single-cone and cold lateral condensation techniques showed significantly lower push-out bond strength for tertiary monoblock obturation (P <0.01), respectively with a mean difference of −0.09 (95% CI, −1.13 to −0.67; I2=97%) and of −1.97 (95% CI, −3.19 to −0.75; I2=100%). The warm vertical compaction subgroup showed no statistically significant difference between tertiary monoblock and conventional systems (P =0.13), with a mean difference of 0.49 (95% CI, −0.14 to 1.12; I2=10%). Conclusion: Tertiary monoblock systems have a push-out bond strength similar to conventional systems when used with warm vertical compaction

    Nanoarte: ciência e tecnologia dos materiais

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    Os objetivos principais são evidenciar a parceria e a interlocução entre as áreas de engenharia de materiais, design e comunicação social que foram possíveis por meio da colaboração entre o Centro Universitário Teresa D’Ávila (Unifatea) e a Escola de Engenharia de Lorena da Universidade de São Paulo (EEL-USP), no Departamento de Materiais, contribuir com a popularização da nanociência e da nanotecnologia e ajudar na evolução das pesquisas relacionadas às áreas envolvidas. A metodologia foi baseada em duas etapas: a obtenção de micrografias em escala nanométrica mediante o microscópio eletrônico de varredura (MEV), com uma amostra de óxido de alumínio e de terra de diatomáceas, e o processamento digital das micrografias com a utilização de softwares de edição de imagens. As micrografias obtidas via MEV assemelham-se a imagens do nosso cotidiano, ou até mesmo a paisagens encontradas na natureza, abrindo, dessa forma, espaço para reflexões acerca da vida e da ciência

    Salivary characteristics may be associated with burning mouth syndrome?

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    Burning mouth syndrome (BMS) it is characterized by burning and uncomfortable sensations with no clinical alterations or laboratory findings. The evaluation of the salivary characteristics of people with BMS can help the understanding of the pathogenesi

    The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability

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    Chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. Its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) ≈500 ORFs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) wide-spread utilization of quorum sensing for control of inducible systems, all of which underpin the versatility and adaptability of the organism. The genome also contains extensive but incomplete arrays of ORFs coding for proteins associated with mammalian pathogenicity, possibly involved in the occasional but often fatal cases of human C. violaceum infection. There is, in addition, a series of previously unknown but important enzymes and secondary metabolites including paraquat-inducible proteins, drug and heavy-metal-resistance proteins, multiple chitinases, and proteins for the detoxification of xenobiotics that may have biotechnological applications

    Bioactive dental materials: state art and technology foresight

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    Bioactive materials are able to promote an induced and programmed physiological response in living tissue, cells or organisms. The dentin-pulp complex has a number of biologically active molecules in its composition, such as transforming growth factor-ß1 (TGF-ß1) and bone morphogenetic protein-7 (BMP-7) that acts in repair and regeneration events of teeth. A better understanding of dentin matrix proteins may allow exploring new treatments with materials for biologically based therapies. Initially, this study aimed to analyze the state of the art and technique of treatments for vital pulp in order to assess the recent advances and future prospects in the sector. A literature search was conducted in papers (PubMed, Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO and The Cochrane Library) and patents databases (Questel Orbit, USPTO, EPO, JPO, the INPI and Patentscope). It was analyzed 799 documents related to materials for dentin-pulp complex protection, which showed that calcium hydroxide cement and mineral trioxide aggregate (MTA) have been the most studied over the years. Recent advances in MTA derived materials (calcium silicate, calcium aluminate, calcium phosphate cements) and bioactive materials containing proteins showed promising results that could improve treatments for vital pulp in the near future. In addition, a systematic review was conducted to evaluate the efficacy of deliver bioactive dentin molecules in vital pulp treatments. A total of 32 animal experiments were included in the analysis. In general, the use of bioactive proteins potentiated tertiary dentin formation in direct and indirect pulp capping, promoting a lower initial inflammatory response. Bioactive materials showed potential use for new therapeutic approaches focused on repair and regeneration processes of dental organ.Sem bolsaMateriais bioativos são capazes de promover uma resposta fisiológica induzida e programada nos tecidos vivos, organismos ou células. O complexo dentino-pulpar possui uma série de moléculas biologicamente ativas em sua composição, como os fatores de crescimento transformadores-ß1 (TGF-ß1) e as proteínas morfogenéticas ósseas-7 (BMP-7), que atuam em eventos de reparo e regeneração dental. A melhor compreensão dessas proteínas pode permitir explorar novos tratamentos com materiais destinados a terapias biologicamente ativas. Esse trabalho visou inicialmente analisar o estado da arte e da técnica dos tratamentos para polpa vital de modo a avaliar os avanços recentes e as perspectivas futuras no setor. A busca na literatura foi conduzida nas bases de dados de artigos (PubMed, Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO and The Cochrane Library) e de patentes (no sistema Questel Orbit, USPTO, EPO, JPO, INPI e Patentscope). Foram analisados 799 documentos referentes à materiais para proteção do complexo dentino-pulpar, que mostraram que os cimentos de hidróxido de cálcio e mineral trióxido agregado (MTA) foram os mais estudados ao longo dos anos. Avanços recentes nos materiais derivados do MTA (cimento de silicato de cálcio, aluminato de cálcio, fosfato de cálcio) e nos materiais bioativos contendo proteínas dentárias apresentaram resultados promissores que poderiam melhorar os tratamentos para polpa vital no futuro. Além disso, foi feita uma revisão sistemática nas bases de artigos com o propósito de avaliar a eficácia do uso de moléculas dentinárias bioativas nos tratamentos para polpa vital. Um total de 32 experimentos em animais foram incluídos na análise. De maneira geral, o uso de moléculas bioativas potencializou a formação de dentina terciária no capeamento pulpar direto e indireto, promovendo uma menor resposta inflamatória inicial. Os materiais bioativos apresentaram potencial aplicação para novas abordagens terapêuticas com foco nos processos de reparo e regeneração do órgão dental

    Elementos que a influenciam o processo de inovação em uma universidade pública brasileira

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    The aim of this qualitative study was to analyze the elements that influence the process of innovation management in a public university in southern Brazil. It was conducted semi-structured interviews with 19 questions to three groups: six university managers; six researchers with only scientific production (articles) and seven researchers with also technological production (patents). After transcribing the interviews, the content analysis was performed in MAXQDA 12 software (Verbi GmbH, Berlin, Germany). The lack of understanding of the legal part (17.6%) and bureaucratization in the transfer process (14.7%) were the most frequently reported difficulties in the process of technology transfer. After identifying the main elements of innovation management in a public university, we proposed a new model in which the research projects are developed in conjunction with the productive sector since the beggining of technological development. Public policies and management measures to facilitate the interaction between academia and the productive sector can facilitate technology transfer and, consequently, management of innovation.O objetivo deste estudo qualitativo foi analisar os elementos que influenciam o processo de gestão da inovação em uma universidade pública do sul do Brasil. Foram realizadas entrevistas semi-estruturadas com 19 perguntas a três grupos: seis gestores universitários; seis pesquisadores com apenas produção científica (artigos) e sete pesquisadores com produção tecnológica (patentes). Após a transcrição das entrevistas, a análise de conteúdo foi realizada no software MAXQDA 12 (Verbi GmbH, Berlim, Alemanha). A falta de compreensão da parte jurídica (17,6%) e a burocratização no processo de transferência (14,7%) foram as dificuldades mais freqüentemente relatadas no processo de gestão da inovação. Depois de identificar os principais elementos da gestão da inovação em uma universidade pública, propusemos um novo modelo no qual os projetos de pesquisa são desenvolvidos em conjunto com o setor produtivo desde o início do desenvolvimento tecnológico. Políticas públicas e medidas de gestão para facilitar a interação entre o meio acadêmico e o setor produtivo podem facilitar a transferência de tecnologia e, consequentemente, a gestão da inovação

    Single-shade Composite Resins: A Scope Review and a Laboratory Study

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    The study will be divided into three phases and the first will correspond to the scoping review, where eight databases will be consulted (PubMed (Medline), Scopus, The Cochrane Library, Embase, Web of Science, BBO, Lilacs, IBECS) and the results will be evaluated with Rayyan. The following data will be tabulated: Tested resins and sample size per group, specimen and shade, preparation and size, evaluated properties, methodology and main results. In phases II and III, physical, biological and optical analyzes of six single-shade commercial resins will be carried out: XtraFill (VOCO), Aura BulkFill (SDI), Vittra APS UNIQUE (FGM), Venus Pearl/ Diamond One Shade (KULZER), Omnichroma (TOKUYAMA) and Essentia Universal (GC). One multi-shade resin will be used as control: Estelite Omega (Tokuyama). The physical properties evaluated (phase II) will be carried out through tests of surface roughness, flexural strength and modulus of elasticity, hardness, sorption and solubility, degree of conversion and radiopacity and the biological properties (phase II) will be evaluated through cultivation in 3D spheroids with gingival fibroblasts. Statistical analysis will be done with SPSS (Statistical Package for Package for Social Sciences, USA). Phase III will assess stability and color matching through color difference analysis (ΔE*) with the aid of the standard formula of the CIEDE2000 model, with the aid of a VITA Easyshade spectrophotometer
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