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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Influência da conicidade do pilar e tipo de agente cimentante na retentividade de coroas metálicas cimentadas sobre pilares personalizáveis de implantes

Dantas, Talita Souza 16 December 2011 (has links)
Several factors must be considered in the selection of angled abutments. In these situations, the clinician should find a practical way to overcome the lack of retention. The purpose of this study was to evaluate the bond strength of metallic crowns cemented to straight and angled customizable abutments with different definitive luting agents. Ninety one regular external hex analogs and abutments were divided in Control group (C): customizable straight abutment cemented with zinc phosphate (n = 10); three groups (n = 10) with 17° angled abutment cemented with zinc phosphate (A17ZP), Panavia F (A17RM) and RelyX U100 (A17R) cements and more three groups (n = 10) with 30° angled abutment also cemented with zinc phosphate (A30ZP), Panavia F (A30RM) and RelyX U100 (A30R) cements. The metal copings were cemented onto their corresponding metal dies and crowns cemented with Panavia F were pre-treated with an alloy primer containing an acid-phosphated monomer (MDP). Data from the all groups were compared to control group with a 1-way ANOVA (α=.05) and Dunnet s test, and comparison between tested groups were done with 2-way ANOVA (α=.05) and Tukey s test. SEM and CLSM evaluation were performed (n = 3) aiming to investigate microscopic features of the abutment-cement-crown interfaces. The mean force (SD) required to dislodge the crowns in the C, A17ZP, A17RM, A17R, A30ZP, A30RM and A30R groups was 357,26 (62,21) N; 251,50 (20,13) N; 397,05 (88,48) N; 328,71 (79,87) N; 276,70 (17,96) N; 377,81 (90,61) N and 335,42 (88,34) N respectively. Panavia F presented the higher tensile bond strength results and zinc phosphate the lower between the tested groups. Only A17ZP group was different from control group (p=.007) and the abutment taper has no influence in retentive values. Zinc phosphate showed an inhomogeneous cement line in SEM and CLSM analysis. The presence of MDP primer could be perceived in CLSM images of Panavia F group. Within the limitations of this in vitro study, the Panavia F presented the higher bonding strength between tested groups, however, all 3 cements tested were similar to control group except A17ZP group, showing that in the conditions of the study they all can be successfully used. / Vários fatores devem ser considerados na seleção dos pilares angulados, assim, muitas vezes, o clínico deve encontrar uma forma prática de superar a falta de retenção resultante das características desse tipo de pilar. O objetivo deste estudo foi avaliar a resistência de união de coroas metálicas cimentadas sobre pilares personalizáveis retos e angulados, cimentados com diferentes agentes de cimentação definitivos. Noventa e um análogos de implantes regulares do tipo hexágono externo foram divididos em Grupo controle (C): pilar reto personalizável cimentado com fosfato de zinco (n = 10); três grupos (n = 10) com pilares angulados de 17° cimentados com fosfato de zinco (A17F), Panavia F (A17RM) e RelyX U100(A17R) e ainda mais três grupos (n = 10) com pilares angulados de 30° também cimentados com cimento de fosfato de zinco (A30F), Panavia F (A30RM) e RelyX U100 (A30R). Coroas de Níquel-Cromo foram confeccionadas e cimentadas em seus pilares correspondentes sendo que as coroas cimentadas com Panavia F foram pré-tratadas com um primer para metal contendo monômero ácido fosfatado (MDP). Dados de todos os grupos foram comparados ao grupo controle por meio da análise de variância ANOVA - One way (α =0,05) e teste de Dunnet, e a comparação entre os grupos testados foi realizada por meio de análise de variância ANOVA Two way (α =0,05) e teste de Tukey. Ainda as avaliações em MEV e MVCL foram realizadas com 3 amostras representativas de cada grupo com o objetivo de investigar as características microscópicas das interfaces pilar-coroa-cimento. A média de força (DP) necessária para deslocar as coroas nos grupos C, A17F, A17RM, A17R, A30F, A30RM e grupos A30R foram, respectivamente, 357,26 (62,21) N; 251,50 (20,13) N; 397, 05 (88,48) N; 328,71 (79,87) N; 276,70 (17,96) N; 377,81 (90,61) N e 335,42 (88,34) N. O cimento Panavia F apresentou os resultados mais elevados de resistência a tração (RT) e o fosfato de zinco apresentou os menores valores de RT entre os grupos testados. Apenas o grupo A17F foi estatisticamente diferente do grupo controle (p = 0,007) e a inclinação das paredes axiais do pilar não influenciou os valores de retenção obtidos. O fosfato de zinco apresentou uma linha de cimentação não homogênea na análise em MEV e MVCL. A presença de primer contendo MDP pode ser percebida nas imagens de MVCL do grupo Panavia F. Dentro das limitações deste estudo in vitro, o Panavia F apresentou a maior resistência de união entre os grupos testados, no entanto, todos os três cimentos testados foram semelhantes ao grupo controle, exceto o grupo A17F grupo, mostrando que nas condições do estudo todos eles podem ser usados com sucesso. / Mestre em Odontologia
112

STADENS BORTGLÖMDA PLATS : En studie om tekniska möjligheter och sociala och ekologiska fördelarmed bebyggelse av platser intill brofästen / The forgotten place of the city : A study of technical possibilities and social and ecological benefits with theconstruction of sites next to bridge abutment

Josephson, Anna, Lundström, Sara January 2017 (has links)
I städer finns det idag många bortglömda outnyttjade platser, så kallade ickeplatser,vars fulla potential inte tillvaratas. Stadens sociala hållbarhet missgynnas ofta av dessaplatser som i många fall ger upphov till otrygghet, obehag och utsatthet för förbipasserande,särskilt för kvinnor. Återkommande bortglömda platser i svenska städerär de så kallade brofästeplatserna, det vill säga platser under broar intill brofästen.Syftet med studien är att visa på potentialen hos outnyttjade brofästeplatser i urbanamiljöer och att belysa förutsättningar, problem och möjligheter samt sociala och ekologiskafördelar med en bebyggelse av dessa platser.Studien visar att bebyggelse av platserna kan skapa säkra och inkluderande områdenatt vistas i, samt öka den upplevda tryggheten på platsen framförallt för kvinnor.Bebyggelse som i någon form aktiverar platsen bidrar till att skapa sociala möten istaden. Bebyggelsen kan även fungera brottsförebyggande, bland annat till följd avett ökat flöde av människor på platsen. Ekologiska fördelar som erhålls är att urbangrönska, och därmed viktiga ekosystemtjänster, kan bevaras i större utsträckning dåde redan hårdgjorda eller grusbelagda ytorna används vid förtätning i urbana miljöeristället för grönområden. Grönska och ekosystemtjänster ger viktiga rekreativa ochsociala värden för stadens invånare och gynnar även förekomsten av biologisk mångfald.Brofästeplatser utnyttjas i andra länder både för bostäder och verksamheter, därföruppstår frågan om varför dess potential inte tillvaratas i Sverige. Platserna tycks haglömts bort eller tidigare inte behövt tas i beaktning vid förtätning av svenska städer,då det funnits annan mark att exploatera. Studien konstaterar att det inte finns någragenerella förbud eller reglemente som reglerar bebyggelse eller icke bebyggelse avbrofästeplatser. Samtliga lagar, krav och bestämmelser vilka gäller vid planering, projekteringoch uppförande av byggnader i Sverige, gäller för platserna. Varför platsernainte nyttjats kan även bero på förutfattade meningar hos aktörer i byggbranschen.Exempelvis förutsätts att krav inom andra områden än det egna inte uppnås. De förutfattademeningarna är ofta grundade i antaganden utanför respektive yrkesprofession,snarare än fakta, vetskap och erfarenhet. För att platserna ska kunna bebyggas krävsdärmed en förändring av inställning och attityd hos aktörer i branschen.Byggnadstypologierna verksamhetslokaler, bostäder och tillfälliga boenden, är allamöjliga att uppföra vid brofästeplatser, med undantag för bostäder vid de brofästeplatserdär ljudnivå och dagsljusinsläpp inte uppnår kraven. Bäst lämpade byggnadstypologiför många urbana brofästeplatser är verksamhetslokaler, där en blandningav funktioner som både kräver konsumtion och inte kräver konsumtion skulle gynnaden sociala hållbarheten i området bäst. Studien visar att bebyggelse av brofästeplatserär möjlig om parametrar som belysts i studien beaktas och tillgodoses. För attmöjliggöra ett sådant projekt krävs en ändrad inställning, attityd och ett gediget tvärprofessionelltsamarbetemellan olika professioner i branschen. Att myndigheter ochaktörer inom byggbranschenskapar ett bättre samarbete skulle inte enbart gynna eneventuell bebyggelse av dessa platser, utan samtliga byggprojekt i Sverige. / In today’s cities there are many forgotten places whose full potential is not being met.The social sustainability of the city is often disadvantaged by these places as theycause insecurity, discomfort and vulnerability to passers-by, especially women. Aforgotten place that is recurring in Swedish cities are so-called bridge abutment-sites,that is, places under bridges next to the abutment. The purpose of the study is todemonstrate the potential of these non-places at bridge abutments in urban environmentsand to highlight the conditions, problems and possibilities as well as the socialand ecological benefits of a development of these sites.The study shows that building these sites can create safe and inclusive areas to stayin, as well as increase the perceived security of the site, especially for women. Housingthat in some way activates the site helps to create social meetings in the city. Thebuilding can also act crime preventive, partly due to an increased flow of people onthe site. The ecological benefits obtained are that urban greenery, and thus importantecosystem services, can be preserved to a greater extent as already impermeable surfacesare used in densification in urban environments instead of green areas. Greeneryand ecosystem services provide important recreational and social values for the city’sinhabitants and also benefit the presence of biodiversity.All laws, requirements and regulations that apply to planning, design and constructionof buildings in Sweden, also applies to these locations. The study finds that there areno general prohibitions or regulations that regulate the construction or non-constructionof bridge abutments. Bridge abutment-sites seem to have been forgotten or previouslynot needed to be taken into account in the densification of Swedish cities, sincethere have been other land to exploit. Another reason why the sites have not been usedis due to preconceived opinions in the construction industry. The preconceptions areoften based on assumptions beyond professional knowledge, rather than facts andexperience. In order for the places to be built, a change of attitude in operators in theconstruction industry is required.The function-types of community center, housing and temporary accommodationare all possible to construct at these sites, with the exception of housing at the bridgeplaces where noise levels and daylight emissions do not meet the requirements. Thebest-suited function-type for many urban bridge abutment-sites is a communitycenter, where a mix of functions that require both consumption and non-consumptionwould best benefit social sustainability in the area.The study shows that construction of the bridge abutment-sites is possible if parameters,as mentioned in the study, are considered and met. In order to enable such aproject, a change in attitude and solid cooperation between several operators in theindustry are required. The cooperation between authorities and operators in the constructionindustry would not only benefit the possible development of these sites, butall construction projects in Sweden.
113

Comprehensive Investigation of Energy Fluence Spectra and MLC Modeling Parameters and their Effects on Dose Calculation Accuracy in Pinnacle

Bashehab, Ali Jameel 10 1900 (has links)
<p>The main focus of this work is to improve the existing clinical machine model within the Pinnacle software planning system (at Juravinski Cancer Center, Hamilton, CA). The incident energy fluence spectrum exiting from the accelerator head is considered an important element of the machine model. Relying on the Pinnacle auto modeling function to determine the relative photon fluence spectrum based on percent depth dose curves fitting for various filed sizes, led to different solutions when the process cycle were repeated. This work presents a new method for determining the Pinnacle photon energy fluence spectrum based on 6 MV Varian 21EX machine. A Monte Carlo simulation spectrum based on BEAMnrc code was attenuated to various depths of water. We determine that, the BEAMnrc spectrum attenuated by 15 cm of water gives the closest agreement between the computed and measured depth dose, similar to the clinical machine spectrum.</p> <p>Implementing the novel spectrum into a machine that retained the same modeling parameters as the clinical machine (21ex-JCC) shows a slight better calculation of the output factor. The MLC model parameters were also investigated, however, adjusting the MLC offset table was found to give significant improvements, especially for the small field geometries.</p> <p>The full impact of adjusting the photon energy spectrum, Off-Axis Softening Factor, MLC rounded leaf tip radius and MLC calibration offsets were investigated individually, resulting in a good model parameter fit. Several proposed supplementary setups were created to further assess our model. This include a geometry sensitive to MLC abutment leakage, the calculation of output factors for long and narrow MLC defined fields, and small square MLC and jaws defined fields. A Sun-Point diode detector was used in the measurement of the output factors for its accurate precision at small geometries. In addition, a GAFCHROMIC EBT2 film dosimetry was used in the measurement of the MLC abutment leakage.</p> <p>Our new model shows superior results in comparison to the clinical 21ex-JCC machine model, especially with MLC small field calculations. We conclude that relying on PDD curves and dose profiles validation method in assessing the model might not necessarily lead to the best machine parameters, since these are not sensitive to subtle changes in parameters that have important dosimetric consequences.</p> / Master of Science (MSc)
114

Reabilitação protética na região auricular: análise por elementos finitos de implantes maxilofaciais extraorais conexão hexágono externo e cone Morse, investigação da fotoestabilidade e caracterização espectroscópica de um elastômero maxilofacial tipo-A / Prosthetic rehabilitation in the auricular region: finite elements analysis of extraoral maxillofacial implants, photostability investigation and spectroscopy characterisation of modified maxillofacial elastomers type-A

Pimentel, Marina Leite 12 April 2017 (has links)
O grande desafio da Implantodontia é alcançar resultados a longo prazo com maior preservação dos tecidos ósseos, resposta adequada dos tecidos conjuntivos e manutenção da estabilidade secundária adequada para a retenção de próteses. Estes fatores evitam a perda indesejável tanto do tratamento reabilitador quanto dos tecidos ósseos de suporte. A região extraoral apresenta menores espessuras ósseas em comparação às regiões de maxila e mandíbula, especialmente no osso temporal. Portanto, os seguintes aspectos foram investigados: (i) Análise pelo Método dos Elementos Finitos (FEA) de 16 modelos virtuais, com aplicação de forças estáticas de tensão e compressão nos pontos médios entre os implantes. Três implantes maxilofaciais extraorais foram posicionados no osso temporal, onde um deles foi posicionado sobre o processo mastóide. Este estudo foi totalmente realizado em ambiente computacional. Foram empregados dois tipos de conexões protéticas e intermediários retos de conicidades 20º e 45º, posicionados virtualmente no modelo de osso temporal, com paralelismo entre eles. Foi desenhada uma barra virtual para retenção protética do tipo barra-clipe da prótese auricular. Foram consideradas as melhores configurações aquelas apresentando distribuição uniforme e branda das tensões de von Mises sobre o tecido ósseo adjacente aos implantes. (ii) Confecção de corpos de prova com graus variáveis de pigmentação para (a) melhorar a reprodutibilidade da coloração (b) entender e reduzir o processo de descoloração para melhorar a longevidade das próteses. Um elastômero maxilofacial tipo A foi pigmentado intrinsecamente de acordo com os seis tons da Escala de Fitzpatrick. Uma técnica de pigmentação foi desenvolvida a partir dos resultados obtidos a partir de uma Escala de Fitzpatrick impressa em papel e dos pigmentos intrínsecos de cores primárias. Este dimetil-metilvinil-siloxano reforçado por platina A 223-30 (Factor II, Inc., Lakeside, AZ, USA) apresenta dureza \"Shore-A\" 30. As amostras foram expostas a fotoenvelhecimento acelerado, e sua degradação mapeada com Espectroscopia UV/Vis/NIR. Concluiu-se que: (i) Os implantes com conexão cone Morse plataforma 3.7 tem melhor comportamento biomecânico com intermediários de 45o e altura de 2mm. Sugere-se planejamento cirúrgico visando a instalação a 3 horas para o temporal esquerdo e 9 horas para o temporal direito, mais 6 horas (mastóide). Implantes com conexão cone Morse plataforma 4.0 apresentaram comportamento biomecânico desejável com intermediários de 20o e alturas de 2mm or 4mm. Para implantes com conexão cone Morse plataforma 4.0, sugere-se a instalação a 6-9-12 horas para o temporal direito, e 12-6-3 para o esquerdo, visando comportamento biomecânico adequado. Sugere-se que os implantes extraorais Brånemark hexágono externo com plataforma 4.1 regular ou expandida sejam preferencialmente empregados com intermediários de 20o. (ii) O SiO2 5% pode ser adicionado à preparação do silicone para retardar o desbotamento da prótese maxilofacial. O TiO2 traz mudanças visuais significativas e pode ser considerado como opacificador. / Major challenges in Implantology include: achieving longevity of implants, bone tissue preservation, connective tissue suitable answer and maintenance of secondary stability in order to retain prosthesis. These factors avoid the undesirable loss of both rehabilitation treatment and supporting bone tissues. The extraoral region has less bone depth compared to the maxilla and mandible regions, especially for the temporal bone. Therefore, the following aspects were investigated: (i) Finite Elements Analysis (FEA) of 16 virtual models, with static application of tension and compression forces in medium points between implants. Three extraoral maxillofacial implants were placed on the temporal bone, which one of them was placed on the mastoid process. This study was made entirely in a computational environment. Two prosthetic connection types and straight Intermediários were employed, with conicities of 20º and 45º, placed virtually on the temporal bone model, mutually parallel. A virtual bar for bar-clip prosthetic retention of auricular prosthesis was designed. The best configurations were considered to be the ones presenting uniform and mild von Mises tension distribution over the bone tissue around the implants. (ii) Generation of samples with varying degree of pigmentation to (a) improve the reproducibility of the colouration (b) understand and minimise the discolouration process to improve prosthetics longevity. A maxillofacial elastomer type A was intrinsically pigmented according to the six tones of the Fitzpatrick Scale. A pigmentation technique was developed from spectroscopy outcomes of paper printed Fitzpatrick Scale and the primary colors pigments. This platinum reinforced dimethyl methylvinyl siloxane A 223-30 (Factor II, Inc., Lakeside, AZ, USA) presents \"Shore-A\" hardness 30. The samples were exposed to accelerated photo aging, and their degradation mapped with UV/Vis/NIR Spectroscopy. The effects of exclusion of oxygen and inclusion of nanoparticle fillers during prosthetic formulation were investigated. It was concluded that: (i) Morse taper prosthetic connection 3.7 platform implants, should be employed with 45o abutments with 2mm height. The surgical planning shall be for placement 3 hours for the left temporal bone and 9 hours for the right, and in 6 hours (mastoid). Morse taper prosthetic connection 4.0 platform implants behaved biomechanically desirably with 20o abutments in 2mm or 4mm heights. For the Morse taper connection 4.0 platform implants, their placement shall be in 6-9-12 hours, for the right temporal, and 12-3-6, for the left temporal, in order to achieve proper biomechanical behaviour. The Brånemark extraoral external hexagon implant, with 4.1 platform (normal or expanded) should preferrably be used with 20o abutments. (ii) The SiO2 5% may be added to the silicone preparation in order to slow maxillofacial prosthesis colour fading. The TiO2 brings visually significant changes and may be considered as an opacifier.
115

Avaliação da sobrecarga em pilares e região periimplantar de implantes cone Morse, ferulizados ou não ferulizados: análise tridimensional em elementos finitos

Magalhães, Guilherme Carminati de 27 February 2015 (has links)
Fundação de Amparo a Pesquisa do Estado de Minas Gerais / This study evaluated the stress distribution in abutments on Morse taper implants and peri-implantar surrounding bone supporting fixed partial dentures, splinted or non-splinted, under axial and oblique loading. The study simulates by means of Finite Element Analysis the loss of two posterior mandibular elements: 1st premolar and 2nd premolar. For mandible simulation a tridimensional box with Type II bone was simulated. The implant system and abutment were obtained using CAD models transferred by the company. Were used Morse taper Implant Titamax CM-Cortical Ø 3.75mm x 9.0mm and Abutment Pilar CM with 2,5mm height (Neodent, Curitiba, PR, Brazil) divided in two groups according the prosthetic rehabilitation: splinted and non-splinted; subjected to two types of loading: axial simulating functional masticatory contact and oblique simulating parafunctional occlusal contact. The implants were positioned 1.5mm under bone level according manufactures recommendation and the abutments were installed with aid of CAD software. The data were analyzed after dynamic loading of 100N in axial direction in the buccal cusp and the oblique loading (angle of 45o) in the distal-lingual cusp; both on 2nd premolar. The results showed lower tensions for F Group on axial loading for both abutment (77.37MPa) and peri-implantar surrounding bone (118.58MPa); however for NF Group axial loading demonstrated similar values as described previously. The oblique loading promoted higher stress for both abutment (505,67MPa) and peri-implantar surrounding bone (505,67MPa). The crowns splinting promotes lower stress on F Group abutment when compared with NF Group regardless the loading type. The stresses on peri-implantar surrounding bone during occlusal axial loading are similar regardless the surface contact between the prosthesis. / Este trabalho avaliou a distribuição de tensões geradas nos pilares protéticos sobre implantes cone Morse e no osso periimplantar que suportam próteses parciais fixas, ferulizadas ou não ferulizadas, sob carregamento axial e oblíquo. O estudo simulou, por meio de Análise em Elementos Finitos, a perda de dois elementos dentais posteriores inferiores: 1° pré-molar e 2° pré-molar. Para simulação da mandíbula, uma caixa tridimensional com propriedades de osso tipo 2 foi confeccionada. O sistema de implante e pilares foram obtidos por meio de modelos em CAD cedidos pela empresa. O estudo utilizou implantes cone Morse (CM) Titamax CM-Cortical® Ø 3,75mm x 9,0mm e Pilar CM de 2,5mm de altura (Neodent, Curitiba, PR, Brasil) dividido em dois grupos, de acordo com a reabilitação protética: ferulizadas e não ferulizadas, cada modelo foi então submetido a dois tipos de carregamento: axial, simulando contato mastigatório funcional e obliquo, simulando contato oclusal parafuncional. Os implantes foram posicionados 1,5mm abaixo da margem óssea, segundo recomendação do fabricante, e os pilares foram instalados com auxilio de software tipo CAD. Os dados foram analisados após aplicação de carregamento dinâmico com força de 100N em direção axial na cúspide vestibular e o carregamento oblíquo (angulação de 45°) na cúspide distolingual, ambos no 2° pré-molar. Os resultados demonstram menores valores de tensão para o grupo F sob carregamento axial, tanto para o pilar (77,37MPa) quanto para o osso periimplantar (118,58MPa); entretanto, mesmo para o grupo NF o carregamento axial demonstrou valores semelhantes aos descritos anteriormente. O carregamento obliquo gera maiores tensões tanto para o pilar (505,67MPa) quanto para o osso periimplantar (505,67MPa) em ambos os grupos. Conclui-se que a ferulização das coroas gera menor tensão no pilar protético no grupo F quando comparado ao grupo NF independente do carregamento. As tensões a nível ósseo periimplantar, durante carregamento oclusal axial apresentaram-se semelhantes independente do tipo de superfície de contato entre as próteses. / Mestre em Odontologia
116

Reabilitação protética na região auricular: análise por elementos finitos de implantes maxilofaciais extraorais conexão hexágono externo e cone Morse, investigação da fotoestabilidade e caracterização espectroscópica de um elastômero maxilofacial tipo-A / Prosthetic rehabilitation in the auricular region: finite elements analysis of extraoral maxillofacial implants, photostability investigation and spectroscopy characterisation of modified maxillofacial elastomers type-A

Marina Leite Pimentel 12 April 2017 (has links)
O grande desafio da Implantodontia é alcançar resultados a longo prazo com maior preservação dos tecidos ósseos, resposta adequada dos tecidos conjuntivos e manutenção da estabilidade secundária adequada para a retenção de próteses. Estes fatores evitam a perda indesejável tanto do tratamento reabilitador quanto dos tecidos ósseos de suporte. A região extraoral apresenta menores espessuras ósseas em comparação às regiões de maxila e mandíbula, especialmente no osso temporal. Portanto, os seguintes aspectos foram investigados: (i) Análise pelo Método dos Elementos Finitos (FEA) de 16 modelos virtuais, com aplicação de forças estáticas de tensão e compressão nos pontos médios entre os implantes. Três implantes maxilofaciais extraorais foram posicionados no osso temporal, onde um deles foi posicionado sobre o processo mastóide. Este estudo foi totalmente realizado em ambiente computacional. Foram empregados dois tipos de conexões protéticas e intermediários retos de conicidades 20º e 45º, posicionados virtualmente no modelo de osso temporal, com paralelismo entre eles. Foi desenhada uma barra virtual para retenção protética do tipo barra-clipe da prótese auricular. Foram consideradas as melhores configurações aquelas apresentando distribuição uniforme e branda das tensões de von Mises sobre o tecido ósseo adjacente aos implantes. (ii) Confecção de corpos de prova com graus variáveis de pigmentação para (a) melhorar a reprodutibilidade da coloração (b) entender e reduzir o processo de descoloração para melhorar a longevidade das próteses. Um elastômero maxilofacial tipo A foi pigmentado intrinsecamente de acordo com os seis tons da Escala de Fitzpatrick. Uma técnica de pigmentação foi desenvolvida a partir dos resultados obtidos a partir de uma Escala de Fitzpatrick impressa em papel e dos pigmentos intrínsecos de cores primárias. Este dimetil-metilvinil-siloxano reforçado por platina A 223-30 (Factor II, Inc., Lakeside, AZ, USA) apresenta dureza \"Shore-A\" 30. As amostras foram expostas a fotoenvelhecimento acelerado, e sua degradação mapeada com Espectroscopia UV/Vis/NIR. Concluiu-se que: (i) Os implantes com conexão cone Morse plataforma 3.7 tem melhor comportamento biomecânico com intermediários de 45o e altura de 2mm. Sugere-se planejamento cirúrgico visando a instalação a 3 horas para o temporal esquerdo e 9 horas para o temporal direito, mais 6 horas (mastóide). Implantes com conexão cone Morse plataforma 4.0 apresentaram comportamento biomecânico desejável com intermediários de 20o e alturas de 2mm or 4mm. Para implantes com conexão cone Morse plataforma 4.0, sugere-se a instalação a 6-9-12 horas para o temporal direito, e 12-6-3 para o esquerdo, visando comportamento biomecânico adequado. Sugere-se que os implantes extraorais Brånemark hexágono externo com plataforma 4.1 regular ou expandida sejam preferencialmente empregados com intermediários de 20o. (ii) O SiO2 5% pode ser adicionado à preparação do silicone para retardar o desbotamento da prótese maxilofacial. O TiO2 traz mudanças visuais significativas e pode ser considerado como opacificador. / Major challenges in Implantology include: achieving longevity of implants, bone tissue preservation, connective tissue suitable answer and maintenance of secondary stability in order to retain prosthesis. These factors avoid the undesirable loss of both rehabilitation treatment and supporting bone tissues. The extraoral region has less bone depth compared to the maxilla and mandible regions, especially for the temporal bone. Therefore, the following aspects were investigated: (i) Finite Elements Analysis (FEA) of 16 virtual models, with static application of tension and compression forces in medium points between implants. Three extraoral maxillofacial implants were placed on the temporal bone, which one of them was placed on the mastoid process. This study was made entirely in a computational environment. Two prosthetic connection types and straight Intermediários were employed, with conicities of 20º and 45º, placed virtually on the temporal bone model, mutually parallel. A virtual bar for bar-clip prosthetic retention of auricular prosthesis was designed. The best configurations were considered to be the ones presenting uniform and mild von Mises tension distribution over the bone tissue around the implants. (ii) Generation of samples with varying degree of pigmentation to (a) improve the reproducibility of the colouration (b) understand and minimise the discolouration process to improve prosthetics longevity. A maxillofacial elastomer type A was intrinsically pigmented according to the six tones of the Fitzpatrick Scale. A pigmentation technique was developed from spectroscopy outcomes of paper printed Fitzpatrick Scale and the primary colors pigments. This platinum reinforced dimethyl methylvinyl siloxane A 223-30 (Factor II, Inc., Lakeside, AZ, USA) presents \"Shore-A\" hardness 30. The samples were exposed to accelerated photo aging, and their degradation mapped with UV/Vis/NIR Spectroscopy. The effects of exclusion of oxygen and inclusion of nanoparticle fillers during prosthetic formulation were investigated. It was concluded that: (i) Morse taper prosthetic connection 3.7 platform implants, should be employed with 45o abutments with 2mm height. The surgical planning shall be for placement 3 hours for the left temporal bone and 9 hours for the right, and in 6 hours (mastoid). Morse taper prosthetic connection 4.0 platform implants behaved biomechanically desirably with 20o abutments in 2mm or 4mm heights. For the Morse taper connection 4.0 platform implants, their placement shall be in 6-9-12 hours, for the right temporal, and 12-3-6, for the left temporal, in order to achieve proper biomechanical behaviour. The Brånemark extraoral external hexagon implant, with 4.1 platform (normal or expanded) should preferrably be used with 20o abutments. (ii) The SiO2 5% may be added to the silicone preparation in order to slow maxillofacial prosthesis colour fading. The TiO2 brings visually significant changes and may be considered as an opacifier.
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D1 Rekonstrukce mostu D1-212 Ostrovačice, příprava realizace stavby / D1 Reconstruction of Bridge on Motorway D1-212 in Ostrovačice, Preparation and Realization of Structure

Kratochvíl, Tomáš January 2018 (has links)
The diploma thesis deals with preparation and realization of D1 reconstruction of D1-212 bridge in Ostrovačice. It is a motorway bridge that transfers traffic over road II / 386. The reconstruction will demolish the superstructure of bridge with bridge equipment and parts of the abutments and their new construction. The preparation of the project solves the engineering report, the block plan drawing, the financial and time schedule - by objects, the budget SO 201, the study of the implementation of the main construction technologys, the project of the site equipment, the design of the main building machines, the SO 201 time schedule, a desigh of the bill of quantities for structure, technical note for superstructure of a bridge and control and test plans. Part of the preparation of the building is the processing of the emergency plan.
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Dálniční estakáda přes široké údolí / Highway multispan bridge over wide wally

Bobek, Lukáš January 2017 (has links)
The aim of this diploma thesis is to design and assess highway bridge. The structure is located on the D1 motorway section bridging a wide valley between the Slovak villages Doľany a Klčov. Three variants have been created – box girder bridge with transverse overhangs, a pair of girder bridge and a pair of box girder bridges. The various proposals were compared with each other. For the most valuable option is selected prestressed box girder bridge with transverse overhangs, which are supported by prefabricated concrete struts. The selected proposal was subsequently elaborated in detail, the load-bearing structure is analyzed using Scia Engineer 16. In calculating the internal forces is adjusted for the effects of construction methods, even as time-dependent analysis TDA. When designing the load-bearing structure it is considered the action of permanent load, also loading from transport and temperature. The structure is assessed for serviceability and ultimate limit states according to current standards. The bridge deck is built by incremental launching method. The principle of this method consists of building the segments in a casting yard located behind the bridge abutment. Each segment is matchcast against the previous one and prestressed to the section of structure already built. The whole superstructure is then jacked forward a distance equal to the length of this segment. This process is repeated until the bridge deck is in its final position. Chosen method of construction is very fast and efficient, to the country in the valley isn´t damage during construction.

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