We present the design and fabrication of a prototype wall-climbing vehicle employing a unique combined locomotion and adhesion system in which the adhesive vacuum is transmitted through moving, perforated treads. Implementing the adhesion/drive system involved a broad range of design challenges, including: developing reliable sealing of sliding and static interfaces, understanding the frictional interactions between the drive treads and various vehicle components and surfaces on which they ride, as well as designing for lightness, manufacturability, and adjustability. The clean sheet design presented in this thesis was taken from concept to functioning prototype in less than 6 months, requiring a considered mix of off-the-shelf components, custom fabrication, and outsourced production. Proof of concept testing is reviewed, including static pressure and force results as well as dynamic vertical surface maneuverability trials.

Post stamp perforation recognition is important factor in authentication of post stamps. Type and perforation size have major influence on price of post stamps. This Masters thesis is handling suggestion of detector of post stamp perforation. Goal of this work is to create application, which will recognize perforation size from photography of post stamp. Application is using OpenCV library.

Recent unexpected experimental observations of the emptying of inverted bottles with perforations has generated interest in modeling and simulation of this phenomenon. It was observed that as a perforation, i.e., a small hole at the "top" of the inverted bottle, is added and enlarged, the overall emptying time first increases to a maximum value and then decreases until it reaches a lower limit. The change in emptying time is associated with a transition from jetting, where only water exits the neck, to glugging, a competition between air and water flows at the neck of the bottle. This paper develops analytical and numerical models to predict emptying time and liquid height as a function of time which capture the jetting-to-glugging transition. When qualitatively compared to experimental data using a bottle with neck diameters of 12.7 mm, 25.4 mm, and 38.1 mm and bottle diameter of approximately 355 mm (equating to several hundred to several thousand seconds to drain) a favorable agreement is observed. These models attempt to explain the transition in terms of a competition between liquid and bubble velocities at the bottle neck and build on an existing model of glugging available in the literature. The paper also explores the first steps taken toward simulation of bottle emptying using a commercial CFD package (Fluent) to simulate draining for a smaller bottle of neck diameter 21.6 mm and bottle diameter of 62.2 mm. The Fluent simulations are used to further elucidate the jetting-to-glugging transition mechanism by simulating emptying with and without perforations. CFD results reported are limited to a few select large perforation diameters. Specifically, a 4 mm perforation taking 15 hours to simulate and 6 mm perforation taking 5 hours to simulate. Despite the lengthy simulation times, both capture only the approximate 2 seconds required to drain the bottle, but demonstrate the effect of the perforation on emptying time. Smaller perforations on the order of 1 mm, which would align with the experimentally determined maximum emptying time would require unfeasibly long simulations for present resources as dictated by required low Courant numbers. Future work with greater computational capability will further expand upon the simulations conducted in this work.

Thermal preconditioning to simulate shipping, handling and storage conditions did not affect distal tip stiffness values for permanently implantable cardiac leads used for pacing and defibrillation. Leads that were subjected to extreme temperatures and temperature cycling did not show changes in buckle force values compared with control specimens which were maintained at ambient room conditions. Absolute differences between all measurements were small, generally under 0.05 N and were attributable to measurement variability. Buckle force values are used to assess the propensity of leads to perforate the heart, a rare but potentially serious complication of implantable pacing and defibrillation systems. Since preconditioning and buckle force measurement methods have not yet been standardized and no published studies exist, it was unknown whether and how much thermal preconditioning could affect lead buckle force. This study involved eight lead models from all four major lead manufacturers and included both pacing and defibrillation leads spanning a range of materials and construction methods. The preconditioning parameters used in the study, such as temperatures and cycle times, were derived from current industry methods. Knowing whether thermal preconditioning is critical to perforation propensity allows lead manufacturers and regulators to more efficiently direct resources towards ensuring reliability as well innovation. The results of this study can also inform the AAMI working group which is developing industry standards for transvenous pacing and defibrillation leads.

[pt] Atualmente, os lasers de alta potência estão sendo testados pela indústria de petróleo como ferramentas de perfuração. Isto ocorre visando dois objetivos fundamentais: (i) aumentar a eficiência na perfuração de poços (maior taxa de penetração) e (ii) melhorar o controle da geometria do corte de revestimento no processo de canhoneio de poço. Este trabalho tem como objetivo contribuir para a tecnologia de canhoneio a laser em rochas carbonáticas através do desenvolvimento de técnicas para aumentar o volume de rocha removida por unidade de tempo. Estudou-se o comportamento termomecânico das rochas carbonáticas quando um laser é utilizado como ferramenta de perfuração no processo de canhoneio. Este conhecimento, obtido através de experimentos e simulações, forneceu dados para a otimização dos parâmetros de perfuração. Foram investigadas as condições de perfuração estática (não há movimentação do feixe do laser) e dinâmica (o feixe do laser percorre uma trajetória espiral). Além disso, foram investigados os resultados da perfuração sob pressão atmosférica e também utilizando uma câmara de pressão projetada para emular a pressão confinante do reservatório. Foram realizados testes experimentais de perfuração a laser com corpos de prova feitos a partir da rocha Bege Bahia. O Bege Bahia é um afloramento utilizado para simular as rochas encontradas nos reservatórios do Pré-sal. A análise destes corpos de prova foi feita através de inspeção e da caracterização por microtomografia, permitindo observar e caracterizar as propriedades da rocha, além da zona termicamente afetada (ZTA), características geométricas do furo, e valores da energia específica da perfuração. Estes resultados foram comparados com resultados obtidos através de simulações. Na modelagem numérica, o processo de canhoneio foi simulado pelo método de elementos finitos através de um modelo termomecânico elástico transiente axissimétrico que verificou as condições de perfuração. O modelo numérico permitiu observar o comportamento das tensões e temperaturas nos testes que envolvem altas temperaturas e altas pressões. Estas grandezas são usualmente difíceis de serem medidas em ensaios experimentais e, portanto, não foram observadas nos ensaios experimentais discutidos nesta tese. Também foram obtidos através da modelagem numérica valores para propriedades da rocha e da zona termicamente afetada (ZTA), características geométricas do furo, e valores da energia específica da perfuração. Os resultados numéricos obtidos foram comparados com resultados dos ensaios experimentais. Os resultados obtidos mostraram que a condição de perfuração dinâmica consegue remover uma quantidade maior de material e produzir uma ZTA maior em Comparação com o teste estático, gerando uma melhor relação tempo x potência. Os testes estáticos e dinâmicos permitiram se chegar às condições de canhoneio mais eficientes para a perfuração da rocha. A análise de tensões do modelo mostrou uma correlação compatível com o perfil do dano encontrado nos ensaios experimentais. / [en] Currently, the petroleum industry is testing high power lasers as drilling tools. The use of these lasers for this application has two main reasons: (i) to increase the efficiency of well drilling (higher penetration rate) and (ii) to improve the control of the geometry of the hole in the casing during the perforation process of the well. The present thesis has the purpose of contributing to the laser perforation technology in carbonate rocks by developing techniques to increase the volume of rock removed by unit of time. The thermo-mechanical behavior of the carbonate rocks was studied when a laser is used as the drilling tool in the perforation process. This knowledge, obtained through experiments and simulations, supplied data for the optimization of the drilling parameters. Both static (the laser beam does not move) and dynamic (the laser beam moves in a spiral trajectory) drilling conditions were investigated. Also investigated were drilling conditions under atmospheric pressure and under high pressure, where a pressure chamber designed to emulate pressure conditions of reservoirs was used. Experimental tests were performed by laser drilling samples made of Bege Bahia rock. This rock is used to simulate rocks found in pre-salt reservoirs. The analysis of these samples was performed through inspection and microtomography characterization, allowing the observation of properties of the rocks and of the heat affected zone (HAZ), geometric characteristics of the hole, and values of the drilling specific energy. These results were compared to the results obtained by simulations. In the numerical modeling, the perforation process was simulated with the finite element method through a transient axisymmetric thermo-mechanical elastic model that verified the drilling conditions. The numerical model allowed the observation of the behavior of the tensions and temperatures in tests involving high temperatures and pressures. These properties are usually difficult to measure in experimental tests and, therefore, were not measured during the experimental tests discussed in this thesis. Also obtained by numeric modeling were: properties of the rock and of the HAZ, geometric characteristics of the hole, and values of the drilling specific energy. The numeric results obtained were compared to the experimental results. The results obtained showed that the dynamic drilling condition is able to remove a larger amount of material and produce a larger HAZ, compared to the static condition, thus generating a better time x power relation. The static and dynamic tests allowed reaching more efficient conditions for rock drilling. The analysis of the tension of the model showed a compatible correlation with the damage profile found in the experimental tests.

L'objectif de ces travaux de thèse est de proposer des approches de modélisation et d'expérimentation de l'impact de structures déformables et indéformables sur différents milieux. Différents modèles analytiques et des simulations numériques sont développés en comparaison aux résultats expérimentaux. Une première partie se consacre à la caractérisation de la similitude entre la réponse à l'impact à l'eau d'un solide et la réponse d'un solide impactant une structure déformable. Des simulations éléments finis (EF) et SPH sont réalisées pour l'impact à l'eau d'un tube cylindrique (sans rupture). Un modèle analytique d'impact à l'eau est proposé pour prédire l'évolution de l'effort (pic, durée). L'analyse des résultats permet de dimensionner un programmateur d'impact solide reproduisant le pic d'effort. Des simulations EF de l'impact sur un tube cylindrique, à géométrie adapté, dans la direction longitudinale, sont réalisées et comparées à quelques expériences tests. Le «flambage dynamique» (dû au comportement inélastique du matériau et aux ondes de déformations) des tubes est alors observé. Une seconde partie traite du cas de la perforation sous impact d'une tôle mince à faibles vitesses d'impact (< 10 m/s, vitesse de déformation < 1000 s-1). Des essais sur puits de chute instrumenté (force, déplacement, déformée de tôle, avancée de fissure) sont analysés. Des simulations EF en éléments coques avec un critère de rupture ductile par endommagement sont réalisées. Les paramètres de rupture dynamique sont identifiés par méthode inverse à l'aide d'essais de résilience Charpy sur l'alliage d'aluminium de désignation 2024 T3. Une analyse des pics de force lors de l'impact permet une meilleure compréhension des mécanismes de perforation. En parallèle, un nouveau modèle analytique, basé sur les énergies impliquées lors de l'impact, est proposé et comparé aux simulations EF. L'étude numérique de la perforation est étendue aux grandes vitesses d'impact et de déformation (100 - 1000 m/s, vitesse de déformation <100 000 s-1) pour identifier les transitions des différents mécanismes de perforation connus (pétalisation, fragmentation des pétales, fragmentation complète). / The objective of this work is to propose approaches to model and to assess experimentally the structural impact on different media. A variety of analytic models and numerical simulations are developed comparing to experimental results. The first part of this work presents a discussion on the similitude between a water impact and an impact on a deformable solid structure. Water impact simulations of a deformable cylinder (without rupture) are performed by finite elements (FE, Coupled Eulerian Lagrangian) and SPH analysis. An analytical model of water impact is proposed for the prediction of peak force evolution. The analysis of results permits to design an impact programmer reproducing this peak force. FE longitudinal impact simulations on cylindrical tubes, with an adapted geometry, are performed and compared with some experiments. The “dynamic buckling” of tubes under impact (due to the material inelastic behavior and to strain waves) is observed. The second part deals with the low velocity perforation (< 10 m/s, strain rate < 1000 s-1) of thin plates. Some experiments on an instrumented drop test (force, displacement, plate shape, crack propagation) are analyzed. Shell FE simulations, with a damage rupture criteria implemented are performed. Parameters are identified by inverse method with the help of Charpy tests made on 2024 T3 aluminum alloy. An analysis of the peak force, during impact, leads to a good understanding of the perforation mechanism. In parallel, a new analytical model, based on an energetic approach of the perforation, is proposed and compared with FE simulations. The numerical perforation study is extended to high velocities and high strain rates (100 - 1000m/s, strain rate < 100 000 s-1) in order to identify different well-known transitions of perforation (Petalisation, petals' fragmentation, total plate's fragmentation).

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.

Este trabalho tem por finalidade o estudo teórico e experimental de avaliação da degradação em postes de madeira utilizados em redes de energia elétrica. Com base em ampla revisão bibliográfica, de dados climáticos de várias cidades do Estado de São Paulo e resultados de ensaios de perfuração controlada realizadas em campo, em vários municípios do Estado de São Paulo, apresenta um modelo de apodrecimento de madeira em contato com o solo, identificando quais as cidades são mais e menos agressivas à madeira nestas condições, propondo a simplificação deste modelo, facilitando sua utilização na previsão da vida útil de madeiras em contato com o solo, predizendo o grau de deterioração destes. O modelo proposto se mostrou bastante adequado, dando uma boa previsão da deterioração de postes nas diversas regiões do Estado. / The purpose of this paper is the theoretical and experimental study of evaluation of timber deterioration in used poles in nets of electric energy. Basing on ample bibliographical reviews of climatic data of some cities in the State of São Paulo and results of controlled perforation testing done in field, in some cities of the State of São Paulo, it presents a model of timber decay in contact with the ground, identifying which cities are more aggressive or less aggressive to the wood in these conditions, proposing the simplification of this model, facilitating its use in the forecast of the timber service life in contact with the ground, predicting the degree of deterioration in them. The proposed model proved to be sufficiently adequate giving a good forecast of the pole deterioration in several regions of the State.

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.