Efeito da remoção do colageno na resistencia ao cisalhamento de dois sistemas adesivos de frasco unico

O objetivo deste trabalho foi verificar os efeitos remoção do colágeno na resistência ao cisalhamento de dois sistemas adesivos de frasco único e examinar a micromorfologia da dentina, antes e após o teste de cisalhamento, em lupa estereoscópica e MEV. Foi usado como substrato dentina planificada de terceiros molares recém-extraídos e armazenados em formal a 10% (pH neutro). Foram usados os adesivos Prime & Bond 2.1 (PB-Dentsply) e Single Bond (SB-3M). Nos grupos controle (1 e 3), após aplicação da ácido fosfórico a 37%, os adesivos foram aplicados de acordo com as instruções do fabricante, enquanto que nos grupos experimentais (2 e 4), após o condicionamento ácido, foi aplicada uma solução de hipoclorito de sódio a 10% (H), por 1 minuto, para remover o colágeno exposto pelo condicionamento ácido. Foram cqnfeccionados cilindros de 3 mm de diâmetro por 5 mm de altura com resina composta Z-100 (3M). Após 24 horas em ambiente úmido a 37 °e, foi realizado o teste mecânico de cisalhamento com velocidade de 0,5 mm/min. Os resultados explorátórios e do Teste de Kruskal-Wallis podem ser observados na tabela abaixo. ... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digitalThe purpose of this study was to evaluate the effect of removing collagen using Single Bond-3M (SB) according to the manufacturer's to four groups and on the shear bond strength for two single-bottle adhesives systems and to examine the dentin surfaces after shear test. The buccal and lingual surfaces of 80 extracted human third molars were ground to expose dentin, then polished with 320, 400 and 600-grit aluminum oxide. Teeth were randomly assigned received the following treatments: group 1, samples were conditioned with 37% phosphoric acid , rinsed and left moist, Prime & Bond 2.1-Dentsply (PB) adhesive was applied according to manufacturer's directions, and restorative Z100 (3M) composite resin was bonded to the dentin surface; group 2, the same procedures were followed as for group 1 except the surfaces were treated with 10% NaOCI for 1 minute, after acid conditioning; group 3, the same technique was followed as for group 1 , recommendations; group 4, the same procedure was followed for group 2, using Single Bond. The specimens were stored. in humidity at 37°C for 24 hours and tested in a shear mode at a crosshead speed of 0,5 mm/minute. The median of results were: G2=21,84, G3=15,99, G1=15,02 and G4=13,82. The Kruskal-Wallis test and multiple comparisons were used for statistical analysis of the data. A 1 minute exposure of dentin to 10% NaOCI following acid conditioning resulted in significant increase on the dentin shear bond strength for Prime & Bond 2.1 (group 2). The same treatment for Single Bond (group 4) resulted in significant reduction on the values of adhesion. Groups 1 and 3 were not statistically different from each other. Group 2 showed more dentin-cohesive failures than the other groups. Under SEM observations, there were morphological differences between the groups treated with NaOCI and those that did not received this treatmen