O propósito deste estudo foi verificar o comportamento inflamatório do tecido osteomedular de ratos quando em contato com agregado de trióxido mineral (MTA Angelus®) ou pasta de moldagem zinco-enólica LS (Vigodent®) adicionada de um tipo de substância radiopacificadora (subnitrato de bismuto ou iodofórmio) e acrescida ou não de hidróxido de cálcio. O grupo controle era constituído por tubos vazios. Os implantes foram inseridos no interior da tíbia e fêmur direitos de cada um dos 51 ratos totalizando 102 amostras. Em cada um dos períodos experimentais de 30, 60 e 90 dias, coletou-se 34 espécimes que, após processamento histotécnico, foram microscopicamente analisados e seus fenômenos julgados com base em um sistema de escores.. Os testes estatísticos de Kruskal-Wallis, Mann Whitney e Dunn, nos permitiram verificar que o reparo aconteceu associado a ambos materiais, embora mais tardio nos grupos com óxido de zinco e eugenol (p=0.05). A adição de um ou outro agente radiopacificador não alterou o caráter inflamatório da pasta e a incorporação de hidróxido de cálcio parece não melhorar seu comportamento biológico(p=0.05). / This study investigated the rat bone marrow healing associated to mineral trioxide aggregate (MTA®- Angelus) or a zinc-oxide impression paste (LS® - Vigodent) added of radiopaque substance (iodoform or bismuth subnitrate) and calcium hydroxide. The control group was composed of empty tubes. The tubes were surgically inserted in the right femur and tibia of 45 rats, resulting in 102 specimens . On each experimental period of 30, 60 and 90 days after surgical implantation, seventeen animal were randomly killed, and had their right leg removed to be fixed, decalcified and embedded in parafin. After histological procedures, the tissue phenomena were examined under light microscope, in a blind way, based on a qualitative scale. The statistical tests showed anticipated repair associated with mineral trioxide aggregate (p≥ 0.05). No statistical differences were found between inflammatory behaviour of both radiopaque agents (p≥0.05). The calcium hydroxide powder added to zinc-oxide eugenol sealer seemed not to improve its biological performance (p≥0.05).

The purpose of this study was to determine if the viscosity of MTA Angelus Fluid is lower than that of Pro Root MTA and MTA Angelus; and to compare the viscosity, leakage and particle size of these materials to determine whether a relationship exists between these properties. The viscosity of each material was measured and compared with the Student's t test. MTA Angelus Fluid's viscosity was significantly lower than the other two materials tested. Microleakage of root end fillings was assessed in a passive diffusion model. Leakage groups were compared with a one-way ANOVA (p < 0.05). No significant difference was found. Particle size and shape were evaluated with the SEM. MTA Angelus Fluid has a lower viscosity than the other materials tested. There was no significant difference in the sealing ability of the three materials tested and there was no apparent variation in each material's particle size or shape.

Vital pulp therapy is the group of procedures indicated to maintain pulp vitality allowing for continued root development and apical closure in the presence of pulp exposure due to caries or trauma. Complete maturation results in stronger tooth structure that is more able to withstand occlusal forces. Historically, calcium hydroxide (Ca(OH)2) was the material of choice for a vital pulpotomy. Recently mineral trioxide aggregate (MTA) has been used as a pulp sealing material because of its biocompatibility and its ability to induce hard tissue barrier formation. The purpose of this retrospective study was to evaluate the clinical and radiographic outcome of vital pulp therapy procedures performed with MTA. All patients receiving MTA pulpotomies and MTA pulp caps at Virginia Commonwealth University School of Dentistry Graduate Endodontic Practice between November 30, 2009 and August 15, 2013 were recalled and evaluated for presence or absence of clinical symptoms, pulp vitality, radiographic evaluation of continued root development, dentin bridge formation or pulp canal obliteration. Results were analyzed descriptively. At time of treatment caries was found to be the most common etiologic factor. Fifty-seven percent of cases were symptomatic at time of treatment (43% asymptomatic). Forty-seven percent of the teeth presented with immature apices (53% with radiographically closed apices). Overall recall rate was 50%. At recall all teeth were clinically asymptomatic. Forty seven percent of teeth tested normally to cold (33% were non-responsive to cold) at recall. Pulp canal obliteration was seen in 6 cases, 4 molars and 2 anterior teeth. In conclusion, MTA pulpotomy and MTA direct pulp caps are a predictable treatment modality for young vital permanent teeth affected by caries or trauma.

AIM:  to evaluate the flow, working time, setting time, film thickness and solubility of a novel root canal sealers (MTA Fillapex) in comparison with a zinc oxide-eugenol– based sealer (Tubli-Seal), epoxy resin-based sealers (AH 26), a calcium hydroxide-based sealer (Apexit Plus), and a silicone-based sealer (ReokkoSeal Automix). MATERIALS AND METHODS: ISO 6876/20012 specifications were followed except for the solubility test. Solubility was measured by the amount of material extracted from the specimens left in water over 24 hr period. Film thickness was measured as the distance between weighted glass slides containing a standard quantity of sealer. Flow was assessed by rate of sealer extrusion through a standard bore diameter, after unit time. Working time was taken as the point at which flow rate was reduced by 10%. The indentation test using a modified Gilmore needle was employed to investigate the setting times. RESULTS: ReokkoSeal Automix and MTA Fillapex were the least soluble, whilst Tubli- Seal was the most unstable in water. Also, Tubli-Seal had the highest film thickness. All sealers showed comparable flow rates. The working time varied from 30 min for MTA Fillapex to 4 hr for AH 26. The range of setting times recorded was from 64 min for Tubli-Seal Xpress to more than 5 hr for AH 26. CONCLUSIONS: MTA Fillapex and RoekoSeal Automix showed the greatest stability in Solution. The film thickness values in increasing order were: AH26 < Apexit plus = RoekoSeal Automix < MTA Fillapex < Tubli-Seal Xpress. The flow rates for Tubli-Seal xpress, AH26, and RoekoSeal Automix are statistically similar, while Apexit plus and MTA Fillapex are statistically similar. The working times for all sealers were greater than 30 min. AH26 did not set when incubated in volumes sufficient to fill the test matrices. / 2018-09-28T00:00:00Z

Ser man på ett tio års perspektiv, så har det i genomsnitt en person i månaden dött på den svenska byggbranschen. Många av dödsfallen beror på organisatoriska brister, det kan exempelvis vara att man gjort otillräcklig undersökning av arbetstagarens erfarenhet eller bristfälliga skyddsronder. I en studie uppskattades det att ungefär 60 % av Europas olyckor inom byggbranschen var direkt eller indirekt på grund av organisatoriska orsaker. I mitt projekt vill jag analysera hur ett byggföretag hanterar sin arbetsmiljöorganisation. Projektet är en fallstudie av hur företaget hanterade arbetsmiljöorganisationen i ett av byggprojekten. Vilket har genomförts av byggföretaget MTA Bygg och Anläggning. I projektet har jag begränsat arbetsmiljöorganisationen till roller inom arbetsmiljöorganisationen, förberedelser för arbetsmiljövänligt arbete samt systematiskt arbetsmiljöarbete. Genom litteraturstudier, internetstudier och kvalitativa intervjuer har jag undersökt vilka faktorer som ger en bra arbetsmiljöorganisation. Jag genomförde intervjuer med inom arbetsmiljöorganisation samt studerade dokument för arbetsmiljön hos företaget för att kunna analysera byggprojektet. Jag ville ta reda på hur företaget kunde förbättra sig och vad man skulle kunna lära av byggföretaget. / Looking at a 10 year perspective, in average there has been one death a month in the Swedish construction industry. Many of the deaths is due to organizational flaws, examples of this could be inadequate survey of a workers experience or inadequate safety inspections. One study estimated that nearly 60% of Europe’s accidents in the construction industry were indirectly or directly due to organizational causes. In my project I wanted to analyze how a construction company managed their working environmental organization. The project is a case study of how a company handled the working environment organization in one of their construction projects. The construction project is carried out by construction company MTA bygg och anläggning. In this project I have focused on how MTA handles the planning of the working environment, monitoring of work environment, cooperation between working environment profiles and systematic working environment improvements. Through literature studies, internet studies and qualitative interviews I have looked into the factors that provide a good working environmental organization. To analyze the project I conducted interviews with some important people for the working environmental organization and by analyzing the document drawn up for MTA’s construction project. I wanted to find out how the company could improve its working organization and what could be learned from their organization.

Made available in DSpace on 2014-06-11T19:25:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-13Bitstream added on 2014-06-13T19:12:24Z : No. of bitstreams: 1 zagato_ef_me_ilha.pdf: 261736 bytes, checksum: d0251ba5867a2a4a3e37c5f78ca9c4ee (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Desde 1993, o mineral trioxide aggregate tem sido amplamente investigado e os resultados confirmam que ele possui excelentes propriedades físicas, químicas e biológicas. Apesar do sucesso e uso deste cimento, duas dificuldades têm sido apontadas pelos profissionais: o difícil manuseio e tempo de presa muito longo. Recentemente, um novo cimento endodôntico, intitulado CER, foi desenvolvido no laboratório do grupo Vidros e Cerâmicas. A inclusão de uma emulsão em sua composição deu ao cimento uma extraordinária consistência de trabalho e uma acentuada redução no tempo de presa. O primeiro estudo com o material mostrou que o CER tem a mesma habilidade de liberar íons que o mineral trioxide aggregate. Como continuidade na caracterização do CER, este trabalho apresenta resultados obtidos com o estudo do efeito do tamanho de partículas do pó de cimento no tempo de presa e na expansão térmica, e um estudo comparativo de infiltração marginal entre o CER e o MTA-Angelus. / Since 1993, the mineral trioxide aggregate has been widely investigated and the results confirm that it has excellent physical, chemical, and biologic properties. In spite of this, one of the difficulties reported by clinicians when using MTA is its poor handling characteristic and lengthy setting time. Recently, a novel endodontic cements, entitled CER, it was developed in the laboratory of the Glasses and Ceramic group. The inclusion of an emulsion in its composition gave to it an extraordinary handling and one accentuated reduction in the setting time as compared to MTA. The first study with the material showed that CER has the same ability to release ions than the mineral trioxide aggregate. This work presents results obtained from study of effects of particle size of the CER cement powder on setting time and thermal expansion, and from a comparative study of sealing ability between CER and MTA-Angelus.

No description available.

Chez B. subtilis, le régulateur Mta régule l'expression de deux gènes codant pour des pompes d'efflux de drogues, bmr et blt. Ce régulateur joue un rôle physiologique beaucoup plus large que la régulation des gènes impliqués dans la résistance aux drogues puisqu'il régule l'expression d'au moins 18 autres gènes. Dans un mutant mta la quantité de protéine CpgA est très diminuée. Cette protéine est une GTPase impliquée dans l'assemblage du ribosome et dans la formation de la paroi. Cette diminution est supprimée par une mutation secondaire qui restaure un niveau intracellulaire de CpgA supérieur à celui de la souche sauvage. Cette mutation confère également un avantage de croissance, sur la souche sauvage et sur le mutant mta, au double mutant résultant. L'augmentation de la quantité de CpgA est corrélée avec l'augmentation du niveau d'expression du gène cpgA ainsi que de celui des gènes def et prpC avec lesquels cpgA est en opéron. Le gène def code pour une déformylase, une protéine impliquée dans la traduction, et prpC pour une Ser/Thr phosphatase capable de déphosphoryler CpgA. Dans le mutant supprimé, la surexpression de l'opéron def-cpgA est accompagnée d'un phénotype drastique de cellules enchaînées et immobiles en phase exponentielle de croissance (phénotype Mhp). Ces cellules contiennent le facteur alternatif de transcription SigD nécessaire à l'expression des gènes dont les produits sont impliqués dans la mobilité cellulaire et dans le clivage des septa lors de la division cellulaire, mais SigD est inactif dans ces cellules (SigD OFF). / In B. subtilis, the regulator Mta regulates the expression of two genes encoding drug efflux pumps, bmr and blt. This regulator has a physiological role far wider than the regulation of genes involved in resistance to drugs since it regulates the expression of at least 18 other genes. In a mta mutant, the amount of the CpgA protein is markedly reduced. This protein is a GTPase involved in ribosome assembly and in cell wall expansion. This decrease is suppressed by a secondary mutation that restores a higher level of intracellular CpgA than that of the wild type strain. This mutation also confers a growth advantage to the resulting double mutant over the wild type and the mta mutant strains. The increased amount of CpgA is correlated with increased level of cpgA gene expression and of the prpC and def genes with which cpgA is in operon. The def gene encodes a deformylase, a protein involved in translation, and prpC for a Ser / Thr phosphatase able to dephosphorylate CpgA. In the double mutant, overexpression of the def-cpgA operon is accompanied by a drastic phenotype of chained non-motile cells in the exponential phase of growth (Mhp phenotype). These cells contain SigD, an alternative sigma factor, necessary for the expression of genes whose products are involved in cell motility and in the cleavage of septa during cell division, but SigD is inactive in these cells (SigD OFF). In exponential growth phase, a wild type strain of B. subtilis shows a heterogeneous population consisting of cells SigD ON, motile and isolated, and cells SigD OFF, chained and non-motile. In the mta strain, the transition from one state to another is reversible as in the wild type strain.

Objetivo: Avaliar in vivo a resposta tecidual de dentes de cães após perfuração de furca e recobrimento com Biodentine&trade;, em comparação ao MTA e à guta-percha, por meio de análise histopatológica, histoenzimológica, imunohistoquímica e por imunofluorescência. Métodos: Foram utilizados 30 dentes de 3 cães, divididos em 3 grupos: I - Biodentine; II - MTA; e III - Guta-Percha (controle). Após tratamento endodôntico e limpeza da câmara pulpar, perfurações no centro do assoalho foram realizadas intencionalmente em cada dente, as quais foram preenchidas com os diferentes materiais. Após 120 dias, os animais foram eutanasiados e as peças contendo os dentes e tecidos perirradiculares foram submetidas ao processamento histotécnico. Foram realizadas análises histopatológicas semi-quantitativas para avaliação da neoformação de tecido mineralizado e da reinserção de fibras, além de análise imunohistoquímica das proteínas osteopontina (OPN) e fosfatase alcalina (ALP) e imunofluorescência para proteína morfogenética óssea (BMP-2), proteína de adesão do cemento (CAP), sialoproteína óssea (BSP), osteocalcina (OCN) e proteína do cemento 1 (CEMP1) no tecido mineralizado neoformado e na região adjacente. Paralelamente, foi realizada a histoenzimologia para a atividade da TRAP e contagem dos osteoclastos. Os dados foram submetidos aos testes qui-quadrado e Kruskal-Wallis, com nível de significância de 5%. Resultados: Na avaliação do tecido mineralizado neoformado, o grupo controle foi significantemente diferente dos demais grupos (p<0,0001), sendo que não houve formação de tecido mineralizado em nenhum espécime desse grupo. Nos grupos tratados com MTA e Biodentine houve formação de tecido mineralizado em 88% e 92% dos espécimes, respectivamente, sem diferença entre eles (p>0,05). Ainda, o grupo controle apresentou fibras colágenas paralelas à perfuração. Nos grupos tratados com MTA ou Biodentine também houve fibras colágenas paralelas à perfuração, porém com algumas fibras reinseridas perpendicularmente em diferentes áreas do tecido mineralizado neoformado. Todos os tratamentos induziram a expressão de OPN e ALP, porém em menor intensidade no grupo controle e em maior intensidade no grupo tratado com MTA (p<0,05). Apenas o tecido mineralizado formado após o tratamento com MTA expressou BMP-2, BSP, OCN, CAP e CEMP1. Com relação à avaliação dos osteoclastos, não foi possível encontrar diferença estatística entre os grupos (p=0,97). Conclusão: Com base nos parâmetros analisados, pôde-se concluir que o MTA e a Biodentine apresentaram resposta tecidual satisfatória, com formação de tecido mineralizado e reinserção parcial de fibras, podendo ser indicados para o selamento de perfurações de furca. Além disso, o presente estudo elucidou alguns mecanismos de ação pelo quais o MTA e a Biodentine induzem a formação do tecido mineralizado, com expressão dos marcadores da mineralização ALP e OPN, sem interferência na quantidade de osteoclastos. Apenas o MTA estimulou a expressão de proteínas associadas à formação de tecido mineralizado semelhante ao cemento / Aim: This study evaluated in vivo tissue response in dogs teeth after sealing of furcation perforations with Biodentine&trade;, MTA and gutta-percha, by means of histopathological, histoenzymological, immunohistochemical and immunofluorescence analysis. Methods: Thirty teeth of 3 dogs were used, divided in 3 groups: I - Biodentine; II - MTA; and III - Guta-Percha (control). After endodontic treatment, perforations were made on the pulp chamber floor and filled with the different materials. The animals were euthanized after 120 days and the teeth and surrounding tissues were processed for histopathological analysis of new mineralized tissue formation and collagen fiber reinsertion, immunohistochemical analysis of osteopontin (OPN) and alkaline phosphatase (ALP) and immunofluorescence analysis for bone morphogenetic protein (BMP-2), cementum attachment protein (CAP), bone sialoprotein (BSP), osteocalcin (OCN) and cementum protein1 (CEMP1). Histoenzymology was performed for TRAP activity and osteoclast count. Data were submitted to chi-square and Kruskal-Wallis tests (=0.05). Results: Gutta-percha did not induce mineralized tissue formation. MTA and Biodentine formed mineralized tissue in 88% and 92% of specimens, respectively, with no significant difference (p>0.05). In addition, the control group had collagen fibers parallel to the perforation. In the groups treated with MTA or Biodentine there were also collagen fibers parallel to the perforation, but with some fibers reinserted perpendicularly in different areas of the neoformed mineralized tissue. All materials induced OPN and ALP expression, weakest for gutta-percha and strongest for MTA (p<0.05). Only MTA induced BMP-2, BSP, OCN, CAP and CEMP1 expression. Osteoclast count was similar in the groups (p=0.97). Conclusion: Thus, according to the parameters analyzed in this present study, MTA and Biodentine presented satisfactory tissue response, with formation of mineralized tissue and partial reinsertion of fibers, and could be indicated for sealing furcation perforations. In addition, the present study elucidated some mechanisms of action by which MTA and Biodentine induce the formation of mineralized tissue, with expression of ALP and OPN mineralization markers, without interference in number of osteoclasts. Only MTA stimulated the expression of proteins associated with the formation of a cement-like mineralized tissue

O objetivo deste estudo foi avaliar a resposta dos tecidos perirradiculares após perfuração de furca intencional e selamento com Biodentine (BD), agregado trióxido mineral (MTA) ou guta percha. Foram utilizados pré-molares de 3 cães, num total de 30 dentes, distribuídos em 3 grupos: experimental BD (n= 14), controle negativo (MTA) (n= 10) e controle positivo (guta percha) (n= 6), por um período de 120 dias. Radiograficamente foi analisada a área correspondente à perfuração de furca. Na análise histopatológica qualitativa foi avaliada a presença, ou não de tecido mineralizado no local da perfuração de furca e adjacências. Na análise histopatológica semi-quantitativa foram atribuídos escores para os parâmetros: presença ou ausência de tecido mineralizado, intensidade do processo inflamatório e reabsorção dos tecidos mineralizados. Na análise histopatológica quantitativa foi medida a espessura de tecido mineralizado na área de perfuração de furca. Foram realizados ensaios de imuno-histoquímica para os marcadores de mineralização: RANKL e osteoprotegerina (OPG). Ensaio de imunofluorescência indireta avaliou a expressão Runx-2 para a síntese de proteínas de mineralização. Os dados foram avaliados pelos testes qui-quadrado, teste exato de Fisher e teste de Mann Whitney, utilizando o programa estatístico Graph Pad Prism 6.0. Os grupos foram comparados entre sí pelo Teste de Kruskal Wallis com pós-teste de Dunn. O nível de significância adotado para todas as análises foi de 5%. Na análise radiográfica a (BD) apresentou melhor desempenho em relação ao MTA, em todos os aspectos analisados. Histologicamente, tanto o MTA quanto a BD induziram a formação de tecido mineralizado, quando comparado à guta percha, que não induziu a formação de tecido mineralizado (p<.001). O selamento completo das perfurações de furca foi mais frequente com o MTA, que induziu a deposição de tecido mineralizado com área e espessura maiores. Tanto as amostras seladas com BD, quanto com MTA, não apresentaram reabsorção óssea em área de furca, apresentaram poucas células inflamatórias e maior intensidade do imunomarcador RUNX2 quando comparadas com a guta percha. A OPG esteve presente em amostras seladas com BD e com MTA. Embora o MTA tenha apresentado maior frequência de selamento completo e maior área e espessura de tecido mineralizado recém-formado, a BD também apresentou bons resultados histopatológicos e pode ser considerada como um adequado material de selamento de perfuração de furca. / The objective of this study was to evaluate the periradicular tissue response after intentional furcation and sealing with Biodentine (BD), mineral trioxide aggregate (MTA) or gutta percha. Pre-molars of 3 dogs were used, in a total of 30 teeth, distributed in 3 groups: experimental BD (n = 14), negative control (MTA) (n = 10) and positive control (gutta percha), for a period of 120 days. The area corresponding to furcation was analyzed radiographically. In the qualitative histopathological analysis, the presence or not of mineralized tissue at the furcation site and adjacent areas was evaluated. In the semi-quantitative histopathological analysis, scores were assigned to the parameters: presence or absence of mineralized tissue, intensity of the inflammatory process and reabsorption of mineralized tissues. In the quantitative histopathological analysis the thickness of mineralized tissue in the furcation area was measured. Immunohistochemical assays were performed for the mineralization markers: RANKL and osteoprotegerin (OPG). Indirect immunofluorescence assay evaluated RUNX-2 expression for the synthesis of mineralization proteins. Data were evaluated by chi-square test, Fisher exact test and Mann Whitney test using the Graph Pad Prism 6.0 statistical software. The groups were compared by the Kruskal Wallis test with Dunn\'s post-test. The level of significance adopted for all analyzes was 5%. In the radiographic analysis the (BD) presented better performance in relation to the MTA, in all aspects analyzed. Histologically, both MTA and BD induced the formation of mineralized tissue when compared to gutta percha, which did not induce the formation of mineralized tissue (p <.001). The complete sealing of furcation holes was more frequent with the MTA, which induced the deposition of mineralized tissue with a larger and thickness area. Both the BD and MTA sealed samples did not show bone resorption in the furcation area, showed few inflammatory cells and a greater intensity of the RUNX2 immunomarker when compared to the gutta percha. OPG was present in samples sealed with BD and with MTA. Although the MTA presented higher frequency of complete sealing and greater area and thickness of newly formed mineralized tissue, BD also presented good histopathological results and can be considered as a suitable furcation perforation sealing material.