Penetration of 35% hydrogen peroxide into the pulp chamber in bovine teeth after LED or Nd:YAG laser activation

This aim of the present study was to evaluate the pulp chamber penetration of 35% hydrogen peroxide activated by LED (light-emitting diode) or Nd:YAG laser in bovine teeth, after an in-office bleaching technique. Forty-eight bovine lateral incisors were divided into four groups, acetate buffer was placed into the pulp chamber and bleaching agent was applied as follows: for group A (n = 12), activation was performed by LED; for group B (n = 12), activation was performed by Nd:YAG laser (60 mJ, 20 Hz); group C (n = 12) received no light or laser activation; and the control group (n = 12) received no bleaching gel application or light or laser activation. The acetate buffer solution was transferred to a glass tube and Leuco Crystal Violet and horseradish peroxidase were added, producing a blue solution. The optical density of this solution was determined spectrophotometrically and converted into microgram equivalents of hydrogen peroxide. The results were analysed using ANOVA and Tukey's test (5%). It was verified that the effect of activation was significant, as groups activated by LED or laser presented greater hydrogen peroxide penetration into the pulp chamber (0.499 +/- 0.622 microg) compared with groups that were not (0.198 +/- 0.218 microg). There was no statistically significant difference in the penetration of hydrogen peroxide into the pulp chamber between the two types of activation (LED or laser). The results suggest that activation by laser or LED caused an increase in hydrogen peroxide penetration into the pulp chamber.

Diabetes triggers the loss of tooth structure associated to radiographical and histological dental changes and its evolution to progressive pulp and periapical lesions in rats

The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.

Responses of human dental pulp cells after application of a low-concentration bleaching gel to enamel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transdentinal cytotoxicity of resin-based luting cements to pulp cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise do pré-mix de breu esterificado e policloreto de alumínio como agente de colagem interna em sistemas alcalinos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Utilização de resíduos agronômicos da mandioca para fabricação de papéis especiais como recurso alternativo para a comunicação visual

The air part of the cassava is a residue which presents possibilities of being used as a non-wooden raw material in the production of pulp due to the fact that its 81 % of the adult plants air part, besides having high availability and presenting a high concentration of fibers. Studies were developed with the purpose of producing the pulps through the kraft process, which is a mix of the Na2S and NaOH in water heated up to the temperature of 160º C for about 90 minutes to the extraction of lignin. The paper sheets obtained in the practices went through an experimenting process. Studies related to the paper characteristics were accomplished in order to assess its use in the visual communication through printing techniques, silk screen, pictures and others graphical processes. The research results are able to conclude the utilization viability of this material in graphics communication.

Avaliação da qualidade da madeira de cinco espécies de Pinus destinadas à produção de celulose

Pós-graduação em Ciência Florestal - FCA

Sanitizers effect in mango pulp and peel antioxidant compounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modificações na produtividade e nas características físicas e químicas da madeira de Eucalyptus grandis causadas pela adubação com lodo de esgoto tratado

O Eucalyptus grandis é uma das espécies mais cultivadas no Brasil devido à sua produtividade e qualidade da madeira. Avaliaram-se o efeito da aplicação de lodo de esgoto tratado (0 a 40 t ha-1 base seca) e uma dose de adubo mineral nos atributos físicos e químicos da madeira de Eucalyptus grandis de árvores com cinco anos de idade, no Município de Itatinga, São Paulo, Brasil. O tipo de solo foi caracterizado como Latossolo Vermelho-Amarelo Distrófico (argila = 120 g kg-1 na camada de 0-20 cm) e o clima, como mesotérmico úmido (Cwa), segundo a classificação de Köeppen. O delineamento experimental foi o de blocos ao acaso, com seis tratamentos e quatro repetições. O diâmetro à altura do peito (DAP), a altura das árvores e o volume de madeira foram obtidos em todas as parcelas de oito árvores com DAP na classe de maior freqüência. As caracterizações físicas e químicas da madeira foram realizadas de acordo com as normas da ABTCP, TAPPI e ABNT. O lodo de esgoto diminuiu a densidade básica da madeira, mas não afetou os teores de celulose, lignina, extrativos e o poder calorífico da madeira. O decréscimo de densidade da madeira pela adubação com lodo de esgoto foi compensado pela maior produtividade de madeira.

Efeitos de absorventes de umidade e de aditivos químicos e microbianos sobre o valor nutritivo, o perfil fermentativo e as perdas em silagens de capim-marandu

The objective of this trial was to evaluate the nutritional value, fermentation profile and dry matter losses of Palisadegrass silages ensiled with either dried citrus pulp, soybean hulls, chemical or microbial additives. The trial was carried out in a completely randomized experimental design and in a factorial arrangement (3 x 5), with three dry matter levels (wet forage or forage ensiled with pelleted citrus pulp or pelleted soybean hulls) and five additives (without or with the presence of bacterial inoculants or the addition of: sodium benzoate, formic acid in the concentration of 62% or 44%), totalizing 15 treatments and 60 experimental silos. The variables analyzed were: nutritional value, losses due to gases and effluents, and dry matter recovery. The use of dried citrus pulp or soybean hulls at the ensiling time increased the dry matter content (29.4 and 28,9%) and decreased the effluent production (4.1 and 3.8 kg/t of fresh matter), also providing fermentable substrate to microorganisms, resulting in increased fermentation coefficient and digestibility of silages. The use of formic acid resulted in silages with higher digestibility and increased water-soluble carbohydrates and crude protein content. This additive was also effective in reducing the losses due to gases and, as a result, increased the total dry matter recovery. The treatment containing homolactic bacteria showed similar trend of increasing the digestibility and reducing the losses due to gases. The use of sodium benzoate was less effective in altering the fermentation pattern of tropical silages. The nutritional value and total dry matter losses of silages ensiled without additives can be considered satisfactory. However, wet forage ensiled with dried citrus pulp and, mainly, with soybeans hulls showed the best results. Treatments containing formic acid had a beneficial effect on the fermentation profile of tropical grass silages.

Preliminary studies on the effects of d-limonene to workers of the leaf-cutting ant Atta sexdens rubropilosa and its implications for control

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Attractiveness of Different Citrus Pulps to the Leaf-Cutting Ant Atta sexdens rubropilosa (Hymenoptera: Formicidae)

The most common control method Uses toxic baits consisted of dehydrated citrus pulp as carrier and attractant. However, the portion of the citrus fruit that is attractive to ants is still Unknown, despite its importance in chemical control. This study compared the attractiveness of different fruit parts of citrus pulps to Atta sexdens rubropilosa workers. Three treatments: pellets of industrial citrus pulp, albedo (mesocarp), and whole citrus pulp were offered randomly to ants and the removal of these substrates by workers was observed. Tie three pulps Were equally attractive to this species (F = 0.8033; p = 0.4633). Although the whole pulp included the epicarp, it was as attractive as the other treatments, possibly because, the material was heated during processing, eliminating any volatile substance that could repel ants.

Metodologia para avaliação do tempo de cozimento e características tecnológicas associadas em diferentes cultivares de mandioca

O consumo culinário de raízes de mandioca é bastante generalizado em todo o mundo, sendo essa raiz amplamente utilizada na forma cozida, assada, frita ou integrando pratos mais complexos. O objetivo deste trabalho foi definir metodologia, avaliar o tempo de cozimento e algumas características associadas a este processo em 26 cultivares de mandiocas. Avaliaram-se os seguintes parâmetros avaliados foram cor da entrecasca; cor da polpa; dificuldade de soltar a entrecasca; dificuldade de palitar; porcentagem de água absorvida/perdida em relação ao peso dos toletes durante o processo de cozimento; cor dos toletes cozidos; formações de pontuações brancas no interior do tolete; formação de gel em volta dos toletes e tempo de cozimento observado para cozimento de 13 palitos. Ao final da avaliação concluiu-se que as melhores cultivares para utilização como mandioca de mesa foram a SRT-1105 (Mico), Milagrosa RG, Mantiqueira, IAC 522-30, IAC 576-70, sendo a última a que apresentou melhor resultado no teste de cozimento.

Viabilidade econômica, desempenho e características de carcaça de garrotes em confinamento alimentados com dietas contendo silagem de capins tanzânia ou marandu ou silagem de milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dinâmica fermentativa e microbiológica de silagens dos capins tanzânia e marandu acrescidas de polpa cítrica peletizada

O experimento foi conduzido com o objetivo de avaliar a dinâmica fermentativa e microbiológica de silagens de capins tropicais acrescidas de polpa cítrica. Os capins tanzânia (Panicum maximum cv. Tanzânia) e marandu (Brachiaria brizantha (Hochst ex. A. Rich) Stapf cv. Marandu) foram colhidos aos 64 e 49 dias de rebrota, respectivamente, e ensilados com 0, 5 ou 10% de polpa cítrica peletizada (PCP), em relação à matéria verde, durante 1, 4, 7, 14, 21, 28 e 56 dias. Foram utilizados silos experimentais de PVC adaptados com válvula do tipo Bunsen para eliminação dos gases. A forragem foi compactada visando obter densidade de 550 kg/m³. O delineamento utilizado foi o inteiramente ao acaso com três repetições, em esquema de parcelas subdivididas. A inclusão de PCP aumentou os teores de MS e diminuiu o pH das silagens. A adição de PCP influenciou os teores de N-NH3 (N total), uma vez que, nas silagens sem PCP, os teores N-NH3 foram significativamente elevados, o que as caracteriza como de qualidade duvidosa. A adição de PCP aumentou a concentração molar dos ácidos acético e propiônico. A população de enterobactérias foi detectada somente no primeiro dia de fermentação nas silagens do capim-tanzânia e até o 18º dia nas do capim-marandu. Nas silagens avaliadas, a população de bactérias homofermentativas foi semelhante à das bactérias heterofermentativas.