Syfte: Syftet med denna studie var att undersöka resistens mot marginala missfärgningar av en adhesivt cementerad keram till emalj beroende på typ av cement, teknik för avlägsnande av överskottscement och kombinationen av de två faktorerna.Metod: 60 extraherade tänder preparerades i emalj med en slipmaskin till en 90° vinkel. Sintrat IPS E-max CAD preparerades till 60 bitar med måtten 3x3x1mm. Glaskerambitarna cementerades med Variolink®Veneer, Variolink®II och Panavia™F 2.0 enligt bruksanvisning med en kraft på 5kg. Varje cementgrupp bestod av 20 provkroppar där cementöverskottet avlägsnades med putsning eller konventionell teknik. Detta ledde till totalt 6 grupper med 10 provkroppar i varje grupp. Provkropparna termocyklades i 5000 cyklar i destillerat vatten med temperaturen 5° C till 55° C, därefter placerades provkropparna 4 dagar i kaffe och 4 dagar i rött vin. Missfärgningsgraden av det marginala cementet avlästes i en blindad studie under mikroskop av två observatörer med signifikant klinisk erfarenhet inom dentala keramer. Resultat: Variolink®Veneer var det minst missfärgande cementet oberoende av avlägsningsteknik, men resultatet var inte statistiskt signifikant. Putsning visade bättre motstånd gällande missfärgning jämfört med konventionell teknik och detta resultat var statistiskt signifikant. Variolink®II tillsammans med putstekniken var det minst missfärgande kombinationerna.Signifikans: Inom de begränsningar en in vitro studie medför kan följande slutsats dras; den viktigaste parametern gällande resistens av marginal missfärgning är ej val av cement utan tekniken för avlägsning av överskottscement. / Purpose: The aim of this study was to investigate the resistance to marginal discoloration of an adhesively cemented bondable ceramic to enamel depending on choice of cement, the technique used for removing excess cement and a combination of the two factors. Method: 60 extracted teeth were prepared in the enamel with a grinding machine to an approximately 90° angle. A block of IPS E-max CAD was sintered and thereafter sliced into 60 pieces with the measurement 3x3x1mm. The ceramic pieces were cemented with Variolink®Veneer, Variolink®II and Panavia™F 2.0 following the manufacturer’s instructions with a force of 5kg (20 specimens in each group). The excess cement was removed by either polishing technique or conventional technique leading to 6 groups with 10 specimens in each group. The specimens were thermocycled for 5000 cycles in 5° C and 55° C distilled water baths and after placed in coffee for 4 days and red wine for 4 days. The discoloration degree of the cement margin was analysed blindly under microscope by two observers with significant clinical experience in dental ceramics.Results: Variolink®Veneer was the least discolored cement but the result was not statistical significant. When comparing polishing and conventional technique, polishing showed least discoloration independent of choice of cement. Variolink®II together with the polishing technique showed least discoloring mean and median value of the 6 groups.Significance: Within the restrictions an in vitro study has, the following conclusion can be made; the most important parameter regarding resistance to marginal discoloration is not the choice of cement but how the excess cement is removed.

Made available in DSpace on 2014-06-11T19:22:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-23Bitstream added on 2014-06-13T18:49:06Z : No. of bitstreams: 1 ennes_r_me_prud.pdf: 1370679 bytes, checksum: eb4f2a4378f82b93f832cc48f75c59ef (MD5) / Os recentes avanços na tecnologia de Sensoriamento Remoto proporcionaram o desenvolvimento de sensores orbitais com altíssima resolução espectral, capazes de fornecer medidas radiométricas em bandas estreitas e contínuas para cada pixel da imagem, definindo curvas espectrais com potencial de discriminar diferentes componentes da matéria. Diante disso, o objetivo geral deste trabalho foi de avaliar a contribuição de imagens hiperespectrais na identificação de componentes opticamente ativos presentes em um corpo d’água, considerado de boa qualidade. Para tanto, uma imagem hiperespectral Hyperion foi adquirida simultaneamente com variáveis limnológicas coletadas em alguns pontos georreferenciados no reservatório de Itupararanga. Após a correção atmosférica da imagem, extraíram curvas espectrais nos locais geográficos dos pontos, nos quais se aplicaram técnicas de análise de espectros, tais como, remoção do contínuo, razão de bandas e análise derivativa. Os dados hiperespectrais originais e os resultantes da aplicação de técnicas foram correlacionados com algumas variáveis limnológicas... / The recent improvements in the technology of Remote Sensing are providing the development of sensors with high spectral resolution that can supply radiometric measurements in narrow and continuous bands for each pixel of the image, defining spectral curves with potential of separating several components of the matter. Due to that, the general objective of this work was evaluating the contribution of hyperspectral images in the identification of optically active constituents present in a body of water, considered good quality. To reach the proposed objective, a hyperspectral imagery of EO-1/Hyperion orbital sensor was acquired simultaneously with limnological variables collected in some points in the body of water. After correcting the atmospheric effects, in the geographical locations of those points, spectral curves of the hyperspectral image were extracted, in which techniques of spectral analysis were applied, such as, continuum removal, derivative analysis and ratio analysis. The hyperspectral original data and the resultants of the application of techniques were correlated with some limnological variables. Of the applied techniques, the derivative analysis provided better differentiation among the optically active constituents... (Complete abstract, click electronic access below)

Orientador: Maria de Lourdes Bueno Trindade Galo / Banca: Renata Ribeiro de Araújo Rocha / Banca: Waterloo Pereira Filho / Resumo: Os recentes avanços na tecnologia de Sensoriamento Remoto proporcionaram o desenvolvimento de sensores orbitais com altíssima resolução espectral, capazes de fornecer medidas radiométricas em bandas estreitas e contínuas para cada pixel da imagem, definindo curvas espectrais com potencial de discriminar diferentes componentes da matéria. Diante disso, o objetivo geral deste trabalho foi de avaliar a contribuição de imagens hiperespectrais na identificação de componentes opticamente ativos presentes em um corpo d'água, considerado de boa qualidade. Para tanto, uma imagem hiperespectral Hyperion foi adquirida simultaneamente com variáveis limnológicas coletadas em alguns pontos georreferenciados no reservatório de Itupararanga. Após a correção atmosférica da imagem, extraíram curvas espectrais nos locais geográficos dos pontos, nos quais se aplicaram técnicas de análise de espectros, tais como, remoção do contínuo, razão de bandas e análise derivativa. Os dados hiperespectrais originais e os resultantes da aplicação de técnicas foram correlacionados com algumas variáveis limnológicas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The recent improvements in the technology of Remote Sensing are providing the development of sensors with high spectral resolution that can supply radiometric measurements in narrow and continuous bands for each pixel of the image, defining spectral curves with potential of separating several components of the matter. Due to that, the general objective of this work was evaluating the contribution of hyperspectral images in the identification of optically active constituents present in a body of water, considered good quality. To reach the proposed objective, a hyperspectral imagery of EO-1/Hyperion orbital sensor was acquired simultaneously with limnological variables collected in some points in the body of water. After correcting the atmospheric effects, in the geographical locations of those points, spectral curves of the hyperspectral image were extracted, in which techniques of spectral analysis were applied, such as, continuum removal, derivative analysis and ratio analysis. The hyperspectral original data and the resultants of the application of techniques were correlated with some limnological variables. Of the applied techniques, the derivative analysis provided better differentiation among the optically active constituents... (Complete abstract, click electronic access below) / Mestre