RESUMO
Abstract This study aimed to evaluate the effects of the application of 10% sodium ascorbate (SA) after in-office bleaching on the penetration of hydrogen peroxide (HP) into the pulp chamber, color change, and microtensile bond strength (µTBS) to the resin-enamel interface. Thirty premolars and thirty molars were randomly divided into three groups (n = 20 each). One group was exposed to deionized water (negative control). The other two groups were bleached with 35% HP in a single session for 3x15 minutes for each application. However, in only one of them, SA was applied for 10 minutes after bleaching. After, the concentration (µg/mL) of HP in each pulp chamber was evaluated by UV-Vis spectrophotometry. Color changes (ΔEab, ΔE00, and ΔWID) were evaluated with a digital spectrophotometer before and in the first week after bleaching. After treatment, molars were restored and sectioned to obtain resin-enamel interface sticks for µTBS at a crosshead speed of 1 mm/min until failure. The HP concentration and µTBS data were analyzed using one-way ANOVA and Tukey tests, and color changes were analyzed by t-tests (α = 0.05). SA application significantly improved the µTBS values and reduced the HP concentrations within the pulp chambers (p < 0.0001). The application of SA significantly interfered with the color changes after bleaching when compared to the control group (p < 0.05). Application of 10% SA after in-office bleaching successfully reduced the penetration of HP into the pulp chamber; however, it decreased color change.
Resumo Este estudo teve como objetivo avaliar os efeitos da aplicação do ascorbato de sódio a 10% (AS) depois do clareamento em consultório na penetração do peróxido do hidrogênio (PH) na câmara pulpar, mudança de cor e resistência de união (RU) da interface resina-esmalte. Trinta pré-molares e trinta molares foram divididos aleatoriamente em três grupos (n = 20). Um grupo foi exposto em água deionizada (controle negativo). Os outros dois grupos foram clareados com 35% PH numa única sessão de 3x15 minutos para cada aplicação. Porém, só um grupo recebeu AS durante 10 minutos depois do clareamento. Depois, a concentração (µg/mL) do PH no interior de cada câmara pulpar foi avaliado com espectrofotometria UV-Vis. A mudança de cor (ΔEab, ΔE00 and ΔWID) foi avaliada como espectrofotômetro digital antes e depois de uma semana do clareamento. Após de cada tratamento, os molares foram restaurados e seccionados em espécimes com interface resina-esmalte para o teste de RU por microtração a uma velocidade de 1 mm/min até a fratura. Os dados da concentração de PH e RU foram analisados usando ANOVA de uma via e teste de Tukey, e a mudança de cor com o teste t (α = 0.05). A aplicação de AS melhorou significativamente a RU e reduziu a concentração de PH na câmara pulpar (p < 0.0001). A aplicação de AS interferiu significativamente na mudança de cor depois do clareamento comprado com o grupo controle (p < 0.05). A aplicação de SA a 10% depois do clareamento em consultório reduziu significativamente a penetração do PH na câmara pulpar e interferiu na mudança de cor.
RESUMO
El calentamiento del almidón de los cereales durante el proceso de extrusión a temperaturas entre 60 y 80ºC, en presencia de agua hace que el gránulo se hinche y alcance la gelatinización, la cual tiene ventajas en cuanto al aumento de la digestibilidad de los nutrientes. Con el objetivo de determinar el coeficiente de digestibilidad de los nutrientes del almidón de maíz, el almidón de yuca, el sorgo y el arroz quebrado cuando son extrusados e incluidos en la dieta de codornices Coturnix coturnix japonicus, se utilizaron 175 codornices machos de 6 semanas de edad y peso promedio de 123±6,3 gramos, distribuidas en un diseño irrestrictamente al azar, con 5 tratamientos, 5 repeticiones por tratamiento y 7 animales por unidad experimental, y según el tratamiento se alimentaron con una dieta de referencia y cuatro dietas experimentales preparadas con 80% de la dieta referencia y 20% del ingrediente a evaluar. Después de un período de adaptación de 10 días, se dio inicio al período experimental con una duración de 10 días, tiempo durante el cual las codornices tuvieron agua y alimento ad libitum. Se realizó el análisis proximal de las dietas, de los alimentos y de las excretas; así mismo se determinaron sus valores de energía bruta por medio de una bomba calorimétrica adiabática; posteriormente se calcularon los coeficientes de digestibilidad total aparente y el valor de la energía metabolizable de los ingredientes. Los resultados fueron analizados por el ANOVA y la prueba de SNK (p<0,05) para establecer la diferencia estadística entre medias de tratamientos. En general todos los ingredientes presentaron altos coeficientes de digestibilidad de los nutrientes, pero, fueron el almidón de maíz y el almidón de yuca los que presentaron los mejores, al ser comparados con el sorgo y el arroz quebrado.
Heating starch from cereals during the extrusion process at temperatures between 60 and 80°C in presence of water makes the granule swell up and reach gelatinization, which has advantages regarding the digestibility of nutrients increase. With the aim to determine the coefficient of digestibility from corn starch, cassava starch, sorghum and broken rice nutrients when they are extruded and included in the diet of quails Coturnix coturnix japonicus, 175 male 6 weeks of age and an average weight of 123±6.3 g quails were used. The birds were distributed in a completely randomized design with 5 treatments, 5 repetitions per treatment and 7 animals per experimental unit and, depending on the treatment they were fed with a reference diet and four experimental diets prepared with 80% of the reference diet and 20% of the ingredient to be tested. After an adaptation period of 10 days, the experimental stage began in a period lasting 10 days during which quails were given water and food ad libitum. The proximal analysis of the diets, food and excreta was carried out; likewise their raw energy values were determined through an adiabatic calorimeter bomb. Later, the total apparent digestibility coefficient and value of energy of the ingredients that could be metabolized were calculated. The results were analyzed by ANOVA and Student Newman Keuls test (p<0.05) to establish the statistical difference between treatment means. In general all the ingredients had high nutrient digestibility coefficients, but corn starch and cassava starch presented the best when compared with sorghum and broken rice.