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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.
1

EFEITO DO ACABAMENTO DE SUPERFÍCIE NA ESTABILIDADE DE COR DE RESINAS PARA PROVISÓRIO SUBMETIDAS A DESAFIO CORANTE / EFFECT OF SURFACE FINISHING ON COLOR STABILITY OF RESINS FOR PROVISIONALS SUBMITTED TO STAINING CHALLENGE

Garlet, Katia 25 August 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The purpose of this study was to investigate the effect of surface finishing on the color stability of the resins used for provisional restorations when immersed in staining agent in different times (7, 30, and 60 days). Thirty-six disc-shaped specimens (sp) were built up for each type of resin: Duralay (polymethylmethacrylate), Trim II (polyethylmethacrylate) and Protemp 4 (bis-acrylic). The sp were prepared using a muffle with the use of a matrix with dimensions of 10x3 mm. Resins were inserted in the muffle, pressed with 1500 kgf and sp were removed after 15 min. The sp were randomly divided into 2 groups: one was finished with 150-grit sandpaper (rough group) and the other with 150 to 1200-grit sandpapers sequence (polished group). These groups were subdivided into two types of immersion: red wine and saliva (control). Specimens from the wine group were immersed 10 minutes per day and were maintained in saliva along the remained period. Specimens from control group were kept in saliva which was changed every 3 days. The color change (ΔE) was measured with the spectrophotometer SP60 using the CIE L*a*b* system. Data were statistically analyzed by ANOVA and Tukey test (5%). The effect of surface, material and time was statistically significant in red wine (p <0.05). The methylmethacrylate-based resin was superior to the other materials in both storage media, in all periods and in polished and rough surfaces. / O objetivo deste trabalho foi investigar o efeito do acabamento de superfície na estabilidade de cor das resinas utilizadas para confecção de restaurações provisórias submetidas a desafio corante em períodos distintos (7, 30 e 60 dias). Foram confeccionados 36 corpos de prova (cps) em forma de disco para cada tipo de resina: Duralay (polimetilmetacrilato), Trim II (polietilmetacrilato) e Protemp 4 (bis-acril). Os cps foram confeccionados em mufla através de uma matriz com dimensões de 10x3 mm. As resinas foram inseridas na mufla, prensadas com 1500 kgf e os cps removidos após 15 min. Os cps foram aleatoriamente divididos em 2 grupos, sendo que um recebeu acabamento de superfície com lixa d água granulação 150 (grupo rugoso) e o outro acabamento com sequência de lixas de 150 a 1200 (grupo polido). Esses grupos foram subdivididos em dois tipos de imersão: vinho tinto e saliva (controle). Os cps do grupo vinho receberam imersões diárias de 10 minutos e no restante do tempo eram mantidos em saliva. Os cps do grupo controle permaneceram em saliva, que era renovada a cada 3 dias. A alteração de cor (ΔE*) foi medida pelo espectrofotômetro SP60 utilizando o sistema CIE L*a*b*. Os dados foram analisados estatisticamente através de Análise de Variância com fator vinculado e Teste de Tukey (5%). O efeito da superfície, material e tempo foi estatisticamente significante em vinho (p<0,05). A resina à base de metilmetacrilato mostrou superioridade nos dois meios de imersão, em todos os tempos e nas superfícies polida e rugosa.

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