The trace mineral trivalent chromium (Cr3+) is an essential nutrient involved in the regulation of carbohydrate, lipid and protein metabolism via an enhancement of insulin action. The present work had as objective to characterize histopathologically and histometrically the hepatic alterations of female Wistar rats, determined by the chromium III administration in drinking water. Adult rats received ration and drinking water ad libitum containing 300 or 500 mg/l chromium III during 4 months. Control animals received only water and ration. All animals were sacrificed by lethal dose of anesthetic. Samples of liver were fixed in 10% formalin for 24 h. Tissues for microscopical pathology were processed using standard procedures. Paraffin sections prepared at 6 µm were stained with haematoxylin and eosin and PAS. Besides the histopathological exam, histometrical techniques were used. The blood was collected and processed for hematological study. Histopathological analysis revealed periportal, midzonal and pericentrilobular zones with parenchyma cells with varying degrees of vacuolation. Many hepatocytes are ballooned and the nuclei were in lysis. The centrilobular vein was dilated and congested. Dilated sinusoids containing erythrocytes were observed. The portal area showed fibrosis, biliar duct proliferation with small cells. Histometric study showed increased cytoplasm and cell volumes, and small values for number of hepatocytes per mm³. Lymphopenia was observed in 500 mg/l Cr3+/l treated animals. These results indicate that the chromium III has a direct participation in liver structures alterations

El cromo trivalente (Cr3+) es un nutriente esencial involucrado en la regulación del metabolismo de carbohidratos, lípidos y proteínas, a través de un estímulo a la acción de la insulina. El objetivo del presente trabajo fue caracterizar histopatológicamente e histométricamente las alteraciones hepáticas de ratas Wistar hembras, provocadas por la administración de cromo III en agua potable. Ratas adultas recibieron ración y agua potable ad libitum, conteniendo 300 ó 500 mg/l de cromo III, durante 4 meses. Los animales control recibieron solo agua y ración. Todos los animales fueron sacrificados con dosis letal de anestésico. Muestras de hígado, fijadas en formol al 10% por 24 h, fueron cortadas a 6 µm y teñidas con hematoxilina y eosina o PAS. Además del examen histopatológico, fueron usadas técnicas histométricas. La sangue fue recolectada y procesada para estudio hematológico. El análisis histopatológico reveló, en la zonas periportal, intermediaria y pericentrolobular, células parenquimatosas con grados variables de vacuolización. Muchos hepatocitos mostraban degeneración baloniforme con núcleos lisados. La vena centrolobular estaba dilatada y congestionada. Se observaron sinusoides dilatados conteniendo eritrocitos. La zona porta mostró fibrosis y proliferación de ductos biliares con pequeñas células. La histometría mostró aumento de los volúmenes de citoplasma y celular, y valores menores para el número de hepatocitos por mm³. Linfopenia fue observada en los animales tratados con 500 mg/l de Cr3+. Estos resultados indican que el cromo III tiene una participación directa en las alteraciones de las estructuras hepáticas

Durante a confecção de restaurações de cerâmica aderidas, a adaptação cervical, o ajuste oclusal e o polimento/acabamento final são procedimentos a serem executados no consultório odontológico após a cimentação adesiva. Os ajustes finais podem resultar na perda do "glaze" da cerâmica, o que requer novo polimento da superfície da restauração, necessitando de atenção especial em relação aos materiais e instrumentos adequados. O objetivo deste estudo foi avaliar a eficiência de diferentes veículos associados a pastas diamantadas indicadas para polimento de cerâmicas odontológicas. Duas pastas de polimento diamantadas (Crystar Paste and Diamond Excell) associadas a quatro veículos (taça de borracha, escova de Robinson, roda de feltro e disco de feltro) foram avaliadas. A cerâmica Ceramco II foi selecionada para a confecção dos espécimes. A rugosidade superficial (Ra) dos espécimes de cerâmica foi determinada por um rugosímetro. Os dados foram submetidos a análise de variância a dois critérios e ao teste de Tukey com nível de significância de 5%. Não houve diferença estatisticamente significante (p>0,01) entre as pastas de polimento avaliadas. Contudo, houve diferença significante (p<0,01) entre os veículos. A interação veículo-pasta revelou diferença significante (p<0,05). Conlcuir que: 1) A escova de Robinson, a roda de feltro e o disco de feltro foram veículos efetivos para serem usados em associação com as pastas de diamante; 2) O uso da taça de borracha como veículo foi menos eficiente para o polimento mecânico das superfícies cerâmicas; 3) Ambas as pastas de polimento apresentaram comportamento similar e eficiente e podem ser indicadas para o polimento final de restaurações cerâmicas com um veículo apropriado

During fabrication of bonded ceramic restorations, cervical adaptation, occlusal adjustment and final finishing/polishing are procedures to be performed at the dental office after adhesive cementation. Final adjustments may result in loss of ceramic glaze, which requires new polishing of the ceramic surface, with special attention for selection of adequate materials and instruments. The purpose of this study was to evaluate the efficiency of different vehicles associated with diamond pastes indicated for dental ceramic polishing. Two polishing pastes (Crystar Paste and Diamond Excell) associated with four vehicles (rubber cup, Robinson bristle brush, felt wheel and buff disc) were evaluated. Disc-shaped specimens were fabricated from Ceramco II dental ceramic. Surface roughness means (Ra) of the ceramic specimens were determined with a rugosimeter. Data were analyzed statistically by two-way ANOVA and Tukey's test at 5% significance level. There was no statistically significant difference (p>0.01) between the polishing pastes. However, there were statistically significant differences (p<0.01) among the tested vehicles. Vehicle-paste interaction showed statistically significant difference (p<0.05) as well. It may be concluded that: 1) Robinson bristle brush, felt wheel and buff disc were efficient vehicles to be used in association with a diamond polishing paste; 2) The use of rubber cup as a vehicle showed poor efficiency for mechanical polishing of the ceramic surfaces; 3) Both pastes provided similar and efficient polishing and may be recommended for use with an appropriated vehicle.

O objetivo deste estudo foi comparar, in vitro, a efetividade de métodos de diagnóstico de lesões de cáries oclusais em dentina. Foram avaliados 38 sítios em 3º molares sem cavidades macroscópicas, de indivíduos adultos, provenientes da cidade de Barretos. Os exames inspeção visual (IV), endoscópio (AcuCam), inspeção visual e uso de sonda exploradora de ponta romba (Táctil), radiografia interproximal (RxC), radiografia digital direta (RxD), e radiografia digital direta com manipulação do contraste e brilho (Rxcb), foram realizados por 5 examinadores não calibrados. Para validação dos dados os dentes foram seccionados e avaliados histologicamente. Concluiu-se que, comparativamente, a efetividade entre os métodos clínicos foram similares, tanto quanto entre os radiográficos. Os métodos clínicos apresentaram um menor número de diagnósticos falsos positivos do que os radiográficos.

The aim of this study was to compare the effectiveness of in-vitro methods for the occlusal dentine caries diagnosis. Thirty-eight sites were evaluated on third molars without macroscopic carious cavitation in adult individuals from the city of Barretos (SP), Brazil. Visual inspection (VI), endoscopic evaluation (AcuCam), visual inspection and blunt-tipped exploratory probes (Tactile), conventional bite-wing radiographs (CR), direct bite-wing digital radiograph (DR), and direct digital radiograph with contrast and brightness controled (DRbc) were used by five observers. In order to validate the data, the teeth were sectioned and histologically evaluated. The average sensitivity and specificity values of the methods were respectively:0,25 , 0,96 (VI); 0,15 , 0,92 (AcuCam); 0,17 , 0,95 (Tactile); 0,45 , 0,73 (CR); 0,33 , 0,80 (DR) and 0,35 , 0,84 (DRbc) , the effectiveness of clinical methods (VI, AcuCam and Tactile) as well as that of radiographic methods (CR, DR and DRbc) were comparatively similar. The clinical methods presented a smaller number of false-positive diagnosis than the radiographic methods. It was concluded that visual inspection is an important diagnostic method; conventional bite-wing and digital radiography aid the diagnosis and are equally efficient to diagnose carious lesions in the dentine of teeth without visible cavitation.

Maternal ingestion of ethanol during lactation alters the chemical composition of milk, results in the appearance of ethanol and acetaldehyde in milk, and exacerbates the effects of ethanol on the rat pups. So that, the effect on respiratory epithelium and anterior and posterior septal glands in 21-day-old suckling pups of ethanol treated mothers was studied. Female rats received dinking water ad libitum containing ethanol (20%) throughout the whole lactation. Control animals received a similar volume of water without ethanol. Lactent rats (21 day-old) were killed by lethal dose of anesthetic. The heads were serially sectioned (6µm thick) in a frontal plain, and stained with haematoxylin and eosin. Cell nuclear parameters were estimated, as well as cytoplasm and cell volume, nucleus-cytoplasm ratio, number and surface densities, and epithelial thickness. Mean body weight of the pups was 34.9 g for the controls and 20.2 g for the treated group. Histologically, the respiratory epithelium was thinner, with more numerous and smaller cells and small nuclei. The posterior septal glands showed smaller acini. In this paper, ethanol induced epithelial (respiratory and glandular) hypotrophy, indicating a direct action in nasal mucous cells, besides retarded development in pups

El consumo materno de etanol durante la lactancia altera la composición de la leche, provoca la aparición de etanol y acetaldehído en la leche y agrava los efectos del etanol en las crías de ratas. De este modo, fueron estudiados los efectos del etanol, administrado a las ratas madres durante la lactancia, sobre el epitelio respiratorio y en las glándulas septales anterior y posterior de las crías lactantes con 21 días de vida postnatal. Las ratas recibieron etanol al 20% en el bebedero, ad libitum durante los 21 días que amamantaron. Los controles recibieron un volumen similar de agua sin alcohol. Las crías fueron sacrificadas en el 21 día. Las cabezas fueran cortadas frontalmente. Los cortes seriados de 6 µm de grosor fueron teñidos con hematoxilina y eosina. Fueron determinados los parámetros nucleares de los epitelios respiratorio y glandular, así como los volúmenes citoplasmático y celular, relación núcleo-citoplasma, densidades numérica y superficial y espesor del epitelio. El peso corporal medio de las crías control fue 34,9 g y en las tratadas 20,2 g. Histologicamente, el epitelio respiratorio se mostró adelgazado en el grupo tratado, constituido por células abundantes y menores, con núcleos menores. La glándula septal posterior presentó ácinos menores. En este trabajo, el etanol indujo un cuadro de hipotrofia epitelial (respiratorio y glandular), indicando una acción directa sobre las células de la mucosa nasal, además de retardar el desarrollo de las crías intoxicadas

A Odontologia de nossos tempos conta com inúmeros recursos para o tratamento de pacientes. Com o desenvolvimento dos materiais adesivos e a introdução de novas técnicas restauradoras, a estrutura dental pode receber diferentes tipos de tratamentos superficiais. O uso do fluxo de óxido de alumínio em alta velocidade para a remoção de estrutura dental foi descrito por Black em 1945, no entanto, a literatura pertinente ao uso do jato de óxido de alumínio ainda permanece escassa no que se refere às alterações produzidas na estrutura dental. Atualmente, com o desenvolvimento de novos equipamentos de ar abrasivo, o procedimento de microabrasão vem sendo incorporado a várias técnicas restauradoras adesivas no preparo de superfícies dentais e superfícies internas de restaurações indiretas, as quais receberão a aplicação de materiais adesivos. O objetivo simples deste estudo foi avaliar as alterações produzidas pelo uso do ar abrasivo sobre o esmalte dental por meio de microscopia eletrônica de varredura, observando-se as alterações micromorfológicas superficiais. A importância deste estudo baseia-se no fato de que tratamentos superficiais alternativos químicos e mecânicos venham a ser introduzidos para o condicionamento de superfícies, inclusive do esmalte dental.

Dentistry nowadays can count on a wide range of resources to treat patients. With the development of adhesive materials and several newly introduced restorative techniques, the dental structure can be subjected to different sorts of surface treatment. The use of aluminum oxide flow at high speed to remove dental structure was described by Black in 1945, however, the literature regarding the use of aluminum oxide jet is still scarce, as far as the alterations occurring in the dental structure are concerned. At the present, with the development of new abrasive air equipment, microabrasion has been added to several adhesive restorative techniques, in the preparation of the dental surface and of inner surfaces of indirect restorations, which will receive the application of adhesive materials. The aim of this study was to assess the alterations produced by abrasive air applied on the dental enamel by means of electronic microscopy, taking into consideration micromorphological surface alterations. The importance of this study is based on the fact that alternative surface treatments both chemical and mechanical could be introduced in surface priming, including dental enamel priming.

O objetivo deste trabalho é verificar, quantitativa e comparativamente, durante a trituração mecânica do amálgama, a ocorrência de perdas de mercúrio em cápsulas, disponíveis em nosso mercado, e os possíveis efeitos dessas perdas sobre as propriedades físicas do material. Os efeitos analisados foram resistência à compressão, alterações dimensionais e fluência estática ("creep" estático).

The purpose of this study was to evaluate quantitatively and comparatively, the occurrence of mercury leakage during the mechanical trituration of amalgam from capsules available in the domestic marketplace, and the possible effects of this leakage on the physical properties of the material. Analyzed items were compressive strength, dimensional change, and static creep.