| Summary: | Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-26T14:53:16Z
No. of bitstreams: 1
TES_DIMAS_JOAO_RODRIGUES_NETO_PARCIAL.pdf: 405454 bytes, checksum: d48967a61777e3e773d5a2112997ee13 (MD5) === Made available in DSpace on 2017-06-26T14:53:16Z (GMT). No. of bitstreams: 1
TES_DIMAS_JOAO_RODRIGUES_NETO_PARCIAL.pdf: 405454 bytes, checksum: d48967a61777e3e773d5a2112997ee13 (MD5)
Previous issue date: 2017-01-19 === Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES === For a satisfactory clinical performance, pre-fabricated Co-Cr cylinders must have metallurgical compatibility to Co-Cr based cast alloys. A uniform interface with adequate union and resistance, with absence of interfacial reaction and porosities must be obtained. The present in vitro study aimed to evaluate the metallurgical compatibility at the interface between pre-fabricated Co-Cr cylinders and alloys for Co-Cr compound casting applying different casting techniques. In manuscript 2 the metallurgical compatibility and the interface between implant and alloy cylinders were evaluated for Co-Cr casting with different melting temperatures. Methodology: Three pre-fabricated Co-Cr prosthetic implant cylinders (Neodent, Pi-Br?nemark, Dentium) were subjected to casting with Co-Cr alloy using different casting techniques (Flame Torch, Induction / Centrifugation, Induction / Vacuum). Optical microscopy and Scanning Electron Microscopy (SEM) were used to characterize the obtained microstructures. The elementary composition of the cylinders and diffusion characteristics in the interfacial region between molten alloy and cylinder were determined by dispersive energy spectroscopy (EDS). Vickers microhardness was measured at interface, cylinder and cast alloy. The ANOVA and Tukey test were used to evaluate microhardness values. In the manuscript 2 cylinders based on Co-Cr were overfused with alloys with different melting temperatures and all microstructural analysis and microhardness tests were performed. Results: In the manuscript 1 a union between pre-fabricated cylinders and Co-Cr based alloys was observed microstructurally. An ideal interface was obtained with absence of interfacial reaction or significant porosities with the casting with the induction techniques (centrifugation and vacuum), but excess of porosities and failures were observed with the Torch casting technique. In manuscript 2 a microstructural bond was observed between the alloys and the cylinder, evidencing that both high melt alloy and low melt alloy presented compatibility with the Co-Cr cylinder. Microhardness values, both in manuscript 1 and in manuscript 2 also proved to form a satisfactory interface. Conclusions: It was concluded from manuscript 1 and 2 that both high and low melt temperature Co-Cr have metallurgical compatibility to pre-fabricated Co-Cr cylinders, showing an ideal interface. However, the technique of casting applied is relevant, and the torch technique has been shown to be less indicated due to the lack of standardization of the obtained results. === Para um bom desempenho clinico, cilindros de pilares pr? fabricados de Co-Cr devem apresentar compatibilidade metal?rgica a ligas de sobrefundi??o a base de Co-Cr. Uma interface uniforme com adequada uni?o e resist?ncia, com aus?ncia de rea??o interfacial e porosidades devem ser obtidas. O presente estudo, in vitro, objetivou atrav?s do manuscrito 1 avaliar a compatibilidade metal?rgica na interface entre cilindros pr? fabricados de Co-Cr e ligas para sobrefundi??o de Co-Cr com diferentes t?cnicas de fundi??o. No manuscrito 2, foi avaliado a compatibilidade metal?rgica e a interface entre cilindro de implante e ligas para sobrefundi??o de Co-Cr com diferentes temperaturas de fus?o. Metodologia: Tr?s cilindros pr?-fabricados para pr?tese sobre implantes em Co-Cr (Neodent, Pi-Br?nemark, Dentium) foram sorefundidos com liga de Co-Cr com diferentes t?cnicas de fundi??o (Ma?arico, Indu??o/centrifuga??o, Indu??o/v?cuo). Microscopia ?ptica e Microscopia eletr?nica de varredura (MEV) foram usadas para caracteriza??o das microestruturas. A composi??o elemental dos cilindros e caracter?sticas de difus?o na regi?o interfacial entre liga fundida e cilindro foram determinadas atrav?s de espectroscopia por energia dispersiva (EDS). Microdureza de Vickers foi aplicada na interface, cilindro e liga fundida. Foi aplicado o teste de ANOVA e Tukey para avalia??o dos valores microdureza. No manuscrito 2, cilindros a base de Co-Cr foram sobrefundidos com ligas com diferentes temperaturas de fus?o e foi realizada toda analise microestrutural e testes de microdureza. Resultados: No manuscrito 1 observou-se microestruturalmente uma uni?o entre cilindros pr? fabricados e ligas a base de Co-Cr. Foi obtida uma interface ideal com aus?ncia de rea??o interfacial ou porosidades significantes com a fundi??o com as t?cnicas por indu??o (centrifuga??o e v?cuo), por?m excesso de porosidades e falhas foram observados com a t?cnica de fundi??o ? ma?arico. No manuscrito 2 observou-se uma uni?o microestrutural entre as ligas e o cilindro avaliado, evidenciando que tanto liga de alta fus?o, quanto de baixa fus?o apresentam compatibilidade ao cilindro de Co-Cr. Valores de microdureza, tanto no manuscrito 1 como no manuscrito 2 tamb?m comprovaram a forma??o de uma interface satisfat?ria. Conclus?es: Concluiu-se atrav?s do manuscrito 1 e 2 que ligas de alta e baixa temperatura de fus?o a base de Co-Cr apresentam compatibilidade metalurgica a cilindros pr? fabricados de Co-Cr apresentando uma interface ideal. Por?m, a t?cnica de fundi??o aplicada ? relevante, sendo que a t?cnica ? ma?arico se mostra a menos indicada devido a falta de padroniza??o dos resultados obtidos.
|
|---|
