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Comportamento mecânica da mola T de Beta-titânio: influência da marca comercial e do alivio de tensão estrutural

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000719591.pdf: 779908 bytes, checksum: 46ae5fb815016e4b4b9801a1a96120f1 (MD5) / Objetivo: Os objetivos do estudo foram (1) avaliar o comportamento biomecânico das molas T confeccionadas com diferentes marcas comerciais de beta-titânio (β-Ti), (2) avaliar a estabilidade do sistema de força das molas 'T pré-ativadas por curvatura quando submetidas ao alívio de tensão estrutural a longo prazo, assim como, (3) comparar seus resultados com as molas préativadas por dobras. Materiais e Métodos: No artigo 1, a amostra foi constituída de 40 molas “T” (6 x 10mm) confeccionadas com fio 0,017” x 0.025” de β-Ti e divididas em 4 grupos de 10 molas de acordo com a marca comercial: Grupo 1 - TMA® (Ormco), Grupo 2 - BETA FLEXY® (Orthometric), Grupo 3 - BETA III TiMo® (Morelli) e Grupo 4 - CNA® (Ortho Organizers). O ensaio mecânico foi realizado utilizando-se um transdutor de momentos acoplado a um indicador para extensometria, adaptado a uma máquina de ensaios mecânicos Emic (DL2000) com célula de carga de 0,1kN e velocidade 5mm/min. Para o ensaio de tração, a amostra foi constituída de 05 segmentos com 30cm de comprimento para cada marca comercial. O ensaio foi realizado na máquina de ensaios mecânicos com célula de carga de 5kN e velocidade de 2mm/min. A análise metalográfica foi realizada por fluorescência de raios X no equipamento Energy Dispersive X-ray Fluorescence Spectrometer. A dimensão dos fios calculada com auxílio de um paquímetro digital com precisão de ± 1μm. A análise estatística foi realizada por meio da análise de variância a um critério (ANOVA) e pós teste de Tukey (α=5%). No artigo 2, a amostra foi constituída de 90 molas de dimensões 6 X 10mm, confeccionadas com fios 0,017” x 0,025” de TMA®, pré-ativadas por curvatura e divididas aleatoriamente em 9 grupos de 10 molas. As molas do grupo 1 (imediato) foram avaliadas logo após a... / Objective: The aim of this study were (1) evaluation of the force system produced by four brands of beta-titanium (β-Ti) wires bent into a T-Loop spring (TLS), (2) evaluate changes in the force system of TLSs preactivated by curvature due to stress relaxation and (3) assess the changes in the force system of TLSs preactivated by bends and curvature. Materials and Methods: The paper 1, the sample consisted of forty springs (6 x 10mm) from 0.017 x 0.025 β-Ti and divided into 4 groups of 10 springs according to wire brand: Group 1 - TMA® (Ormco), Group 2 - BETA FLEXY® (Orthometric), Group 3 - BETA III TiMo® (Morelli) and CNA® (Ortho Organizers). The mechanical testing was performed using a moment transducer coupled to a digital extensometer indicator adapted to an Emic testing machine (DL2000) with a load cell of 0.1kN and speed 5mm/min. For the tensile test, the sample consisted of five 30cm segments of each of the wires. The test was performed on a mechanical testing machine equipped with a load cell of 5kN and speed of 2mm/min. An energy dispersive X-ray fluorescence spectrometer machine was used to determine the surface chemical composition of the wires in each group. The height and width of each wire were measured to the nearest 0.001 mm with a digital micrometer accurate to ± 1μm. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey post hoc test (α=5%). The paper 2, the sample consisted of ninety TLSs with dimensions 6 x 10mm, produced out of .017” x .025” TMA® and preactived by gradual curvature, were randomly distributed into nine groups according to time point of evaluation. Group 1 was tested immediately and the remaining subgroups were tested after they were secured at 5 mm activation for different periods. Groups 2, 3, 4, 5, 6, 7, 8 e 9 were kept activated for 24, 48 and 72 hours... (Complete abstract click electronic access below)

Identiferoai:union.ndltd.org:IBICT/oai:repositorio.unesp.br:11449/104504
Date18 January 2013
CreatorsCaldas, Sergei Godeiro Fernandes Rabelo [UNESP]
ContributorsUniversidade Estadual Paulista (UNESP), Martins, Lidia Parsekian [UNESP]
PublisherUniversidade Estadual Paulista (UNESP)
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis
Format127 f. : il. color.
SourceAleph, reponame:Repositório Institucional da UNESP, instname:Universidade Estadual Paulista, instacron:UNESP
Rightsinfo:eu-repo/semantics/openAccess
Relation-1, -1

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