Thesis (doctoral)--Uppsala University, 1981. / At head of title: From the Department of Orthopaedic Surgery, University Hospital, Sweden. Includes bibliographical references (p. 19-20).

Thesis (doctoral)--Uppsala University, 1981. / Includes bibliographical references (p. 18-19).

Thesis--Wisconsin. / Vita. Includes bibliographical references (leaf 291).

Thesis (M.S.)--Ohio State University, 2005. / Includes bibliographical references (leaves 280-305). Available online via OhioLINK's ETD Center.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 96-104).

Orientador: Wilkens Aurelio Buarque e Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T03:30:15Z (GMT). No. of bitstreams: 1 Costa_MarcelodeAlmeida_D.pdf: 2169259 bytes, checksum: 40e31d0384a05e3f5b7c97d6657b6364 (MD5) Previous issue date: 2009 / Resumo: Este trabalho teve como objetivo, avaliar através da extesometria, a resposta de forças aplicadas sobre abutments de infra-estrutruras implanto-retidas fundidas em ligas de cobalto-cromo, pela técnica de monobloco, simulando caso de protocolo mandibular, foram utilizados 06 implantes com distância de 10 mm entre implantes e com extremo livre Cantilever bilateral com tamanho do 20 mm. Em cada abutment foram colados 04 extensometros, fazendo uma ponte de Wheatstone, após apertamento de todos os componentes a peça em monobloco, foi submetido a um ensaio mecânico com cargas compressivas com valores de 150 N/cm, analisando quantitativamente os dados através da extensômetria, permitindo resultados bem precisos. Os referidos resultados foram obtidos usando os maiores valores registrados em cada ponto de força aplicado, ou seja, nos lados: esquerdo e direito ( cantilever bilateralmente), tanto para carga axial ou em 20º, demonstrou pura deflexão, porem quando a aplicação foi entre as fixações( implantes ) P1eP2,P3eP4,P4 eP5, P5eP6, respectivamente, foi obtido nas fixações mais próximas a aplicação da carga um maior grau de compressão (deflexão) e nas fixações mais distantes uma pequena deflexão negativa indo até conseguir uma deflexão positiva, sugerindo movimento de gangorra / Abstract: The objective of this study was evaluate through extensometry the response of implant-suported frameworks in cobalt-chromium submitted to a load by the technique of monoblock, that simulate a case of mandibular protocol with 06 implants with a distance of 10 mm between each implant and a bilateral cantlever of 20 mm. In each abutment were pasted 04 strain gauges, making a bridge of Wheatstone, after squeezing all components of the piece of the monoblock, was submitted to a test with mechanical compressive loads with values of 150 N, quantitatively analyzing the data through extensometry, allowing accurate results. The results were obtained using the highest values recorded at each point of force applied, in the points L and R (cantilever bilaterally) for both axial load or 20, showed pure deflection, but when the load was applyed between p1 and p2, P3eP4, P4 eP5, P5eP6 respectively, was obtained a greater degree of compression (deflection) closer to the application of the load and more dstant to the applicarion of load, a little negative deflection was found by going to a positive deflection, suggesting movement of seesaw / Doutorado / Protese Dental / Doutor em Clínica Odontológica

No description available.

Orientador: Jose Ricardo de Albergaria Barbosa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-27T15:59:26Z (GMT). No. of bitstreams: 1 Sigua-Rodriguez_EderAlberto_M.pdf: 2176821 bytes, checksum: b803d24031ee26b312d3a029527cb4c4 (MD5) Previous issue date: 2015 / Resumo: Defeitos auriculares são causados geralmente por cirurgias oncológicas ablativas, malformações ou traumas. Prótese auricular é dentre as próteses faciais, a que se propõe a restaurar artificialmente ou aloplasticamente as lesões totais ou parciais da orelha. A retenção da prótese auricular pode ser mecânica, adesiva ou implanto-retida, assim o uso de implantes osseointegráveis para retenção de próteses auriculares tem trazido benefícios na estabilidade. Diferentes sistemas de retenção têm sidos utilizados com especificidades em relação às características na retenção, indicação e limitações. O presente trabalho teve como objetivo avaliar o comportamento mecânico de três sistemas de retenção de próteses auriculares quando submetidos à ciclagem mecânica. Doze modelos de resina acrílica com dois implantes instalados distando 20 mm entre si foram obtidos e divididos em três grupos, estes foram considerados como fatores de estudo: I - Barra-clipe (Sistema INP® - São Paulo - Brasil); II - Magneto (Metalmag® - São Paulo - Brasil ) e III - Ball/O-ring (Sistema INP® - São Paulo - Brasil). Cada grupo foi composto por quatro amostras, que foram submetidas ao teste de ciclagem mecânica de remoção e inserção (f = 0,5 Hz) para determinar a resistência à tração. A máquina servo-hidráulica MTS 810-Flex Test 40 (Eden Prairie, MN- USA) foi utilizada para realizar a ciclagem, com um deslocamento de 2.5mm e uma velocidade de 10 mm/s. Os valores da força de retenção foram obtidos em sete tempos (Inicial, 540, 1080, 1620, 2160, 2700 e 3240). Os dados foram comparados utilizando o teste Kruskal Wallis no programa SPSS 18.0. Os resultados foram considerados estatisticamente significativos para valores de p<0.05. O grupo retido pelo sistema barra-clipe apresentou maior força de resistência à tração (29,61 N) com diferença estatisticamente significativa quando comparado com o grupo retido pelo sistema ball/o-ring (9,41 N) e com o sistema com magnetos (8,62 N). Os grupos com retenção promovida por magneto e pelo sistema ball/o-ring diferiram com significância estatística somente para a tração inicial, que se mostrou maior no sistema ball/o-ring (p<. 05). Ao finalizar o teste de ciclagem o sistema barra-clipe garantiu maior retentividade, os sistemas avaliados apresentam força de resistência à tração compatível com o uso clínico e não tiveram fraturas dos componentes durante a avaliação de simulação de três anos de inserção e remoção / Abstract: Auricular defects are generally caused by ablative cancer surgeries, malformations or traumas. Auricular prosthesis is among the facial prosthesis used to restore artificially or alloplastic the partial or total lesions that effects of the auricular. The auricular prosthesis retention can be mechanical, adhesive or implant-supported. Therefore the use of osseointegrated implants for the retention of auricular prosthesis have brought benefits regarding stability, also different retained auricular systems have been used to show the differences between retention, display and limitations. This study aimed to evaluate the mechanical behavior of 3 retained auricular prosthetic connections when submitted to a mechanical cycling test. To conduct the present study, twelve acrylic resin models with installed implants positioned parallel at 20 mm apart were obtained and divided into three groups according to their retention system with four samples in each group. Three retained auricular prosthesis systems implant-supported: I - Bar-Clip system (INP® System - São Paulo - Brazil); II - Magnet System (METALMAG Ltda® - São Paulo - Brazil) and III - Ball/O-ring system (INP® System - São Paulo - Brazil) were considered as study factors. Each of the samples were submitted to the pull-out test (f = 0,5 Hz) to determine its tensile strength. The mechanical cycling test was performed using the servo-hydraulic machine MTS 810-Flex Test 40 (Eden Prairie, MN- USA) that had a 2.5mm shift at a 10 mm/s velocity. The retaining strength for each of the samples were obtained at 7 intervals: 1st - Initial cycles, 2nd- 540 cycles, 3rd- 1080 cycles, 4th- 1620 cycles, 5th 2160 cycles, 6th 2700 cycles, and, finish interval 3240 cycles. Kruskal-Wallis test was used to compare the differences in tensile strength and statistical analysis was performed using SPSS 18.0 for Windows, p values ?0.05 were considered significant. The tensile strength for the group retained by the bar-clip system (29,61 N) was higher with statistically significant difference when compared to the group retained by the ball/o-ring system (9,41 N) and magnets system (8,62 N). The groups retained by the magnets system and the ball/o-ring system differed with statistical significance only for the initial traction, which was higher for the ball/o-ring system (p?0,05). At the end of the cycling test, the bar-clip system ensured greater retentiveness. The evaluated systems showed a tensile strength compatible with the clinical use and no fractures of the components during the simulation of three years of insertion and removal were observed / Mestrado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Mestre em Clínica Odontológica

Low back pain is also a vast socioeconomic issue which costing American taxpayers more than $50 billion yearly. Estimates state that up to 75% of low back pain is caused by lumbar degenerative disc disease. The nucleus seems plays a critical role in pain related to disc degeneration; it is the starting point of the degenerative cascade. All of these factors make it the focus of novel treatment options. The goal of this study is to create idealized models to determine the shape of nuclear implant best suited to resist the standard shear and torsional stresses that are generated in the lumbar spine. Thus, five nuclear intervertebral disc prosthetics (Implant designs 1-5) were designed. Shear testing was conducted using an Instron, and torsion testing was conducted using the LabVIEW in conjunction with a torsional pneumatic cylinder. Implant design 4 was determined to be the implant design best suited to resist shear stresses. Implant design 3 was determined to be the implant design best suited to allow normal torsion of the spine. Therefore, it was determined that a combination of implant design 3 and implant design 4 might be optimal in terms of shear, torsion, wear, and stability.

The non-invasive measurement of the mass of bone is a clinically relevant problem. The bone is one component of a composite system. At the spine it may include fat, lean and bone mineral. At a hip prosthesis it may include soft tissue, bone mineral and metal. The measurement of the attenuation of photons of different energies can be used to determine the mass of one or all of the components of the composite system. The first system is currently measured using only two photon energies by assuming that it is a two component system. A model was developed which predicts the effect of the third component, fat, and was validated using phantom measurements. Typical parameters for the volume and spatial distribution of fat 𝘪𝘯 𝘷𝘪𝘷𝘰 were determined using CT scans. In combination with the model a median error of 8% is introduced by the third component. The feasibility of using a third energy to correct for the error was investigated. A model for the variance of the bone measurement normalized to emitted photon flux was developed. The optimal set of photon energies yielded a minimum value for the variance. However, this variance was excessively high, requiring a radiation dose 3000 times that for dual photon absortiometry. For the second system a triple photon absorptiometry technique was developed using the isotopes 203-Hg and 141-Ce. The technique was shown to be valid, but the variance was high due to cross-over of high energy photons in the detector and by scattering. In order to make measurements with a precision of 1%, counting times of 70 hours are required. Monte Carlo simulations were performed to determine the optimal geometry to reduce cross-over from scattering. However, cross-over cannot be reduced sufficiently with 203-Hg and 141-Ce. A three isotope source is required to make clinical bone measurements at a prosthesis. / Thesis / Doctor of Philosophy (PhD)