Adhesive Bonding of Resin Composite to Various Ni-Cr Alloy Surfaces Using Different Metal Conditioners and a Surface Modification System

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

Titanium surface topography after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

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

Comparative cytogenetics of eight species of Cycloramphus (Anura, Cycloramphidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Suitability of DNA extracted from archival specimens of fruit-eating bats of the genus Artibeus (Chiroptera, Phyllostomidae) for polymerase chain reaction and sequencing analysis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Femur bone repair in ovariectomized rats under the local action of alendronate, hydroxyapatite and the association of alendronate and hydroxyapatite

P>An evaluation was made of the local action of alendronate sodium (A), hydroxyapatite (HA) and the association of both substances (A + HA), in different molar concentrations, on the femur bone repair of ovariectomized rats. Ninety-eight animals were divided into seven groups: control (C), starch (S), alendronate 1 mol (A1), alendronate 2 mols (A2), hydroxyapatite 1 mol (HA1), hydroxyapatite 2 mols (HA2) and the association of alendronate + hydroxyapatite (A + HA). Rats weighing about 250 g were ovariectomized and 2.5-mm diameter bone defects were made on the left femur 30 days later. Each experimental group had defects filled with appropriate material, except for group C (control). The animals were killed 7 and 21 days after surgery. Histological, histomorphometric and statistical analyses of bone neoformation in the bone defect site were performed. From the histological standpoint, the major differences occurred after 21 days. All specimens in groups C, S, HA1 and HA2 presented linear closure of the bone defect, and most animals in groups A1, A2 and A + HA showed no bone neoformation in the central area of the defect. No statistically significant difference was found among the experimental groups after 7 days; after 21 days, group HA2 presented the highest amount of neoformed bone. There was no significant difference among groups A1, A2 and A + HA in the two study periods. It was concluded that alendronate, either isolated or in association with hydroxyapatite, had an adverse effect on bone repair in this experimental model. Moreover, the hydroxyapatite used here proved to be biocompatible and osteoconductive, with group HA2 showing the best results.

Fracture resistance of endodontically treated teeth with different heights of crown ferrule restored with prefabricated carbon fiber post and composite resin core by intermittent loading

This study evaluated the fracture resistance of endodontically treated teeth restored with prefabricated carbon fiber posts and varying quantities of coronal dentin. Sixty freshly extracted upper canines were randomly divided into groups of 10 teeth each. The specimens were exposed to 250,000 cycles in a controlled chewing simulator. All intact specimens were subjected to a static load (N) in a universal testing machine at 45 degrees to the long axis. Data were analyzed by 1-way analysis of variance and Tukey test (alpha = .05). Significant differences (P < .001) were found among the mean fracture forces of the test groups (positive control, 0 mm, 1 mm, 2 mm, 3 mm, and negative control groups: 1022.82 N, 1008.22 N, 1292.52 N, 1289.19 N, 1255.38 N, and 1582.11, respectively). These results suggested that the amount of coronal dentin did not significantly increase the fracture resistance of endodontically treated teeth restored with prefabricated carbon fiber post and composite resin core. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:e52-e57)

Dentin bond strength: Influence of laser irradiation, acid etching, and hypermineralization

Objective: the purpose of the present study was to investigate the effects of ND:YLF laser irradiation (1.31 J/cm(2); 250 mJ per pulse), acid etching, and hypermineralization on the shear bond strength (SBS) of the Scotchbond Multi-Purpose Plus (3M Dental Products) bonding system. Summary Background Data: Previous studies had shown that the pretreatment of the dentin substrate with laser irradiation can influence the SBS, Methods: Sixty bovine incisors were selected and stored at -18 degrees C, Dentinal buccal surface was exposed and radiographs were taken to control dentin thickness, the specimens were separated into 2 groups: (1) the control, which was kept in distilled water at 4 degrees C; (2) the hypermineralized, which was kept in hypermineralizing solution at 4 degrees C for 14 days, Each group was divided into 3 subgroups according to the type of dentin pretreatment used: M (acid etching + primer + bond); AL (acid etching + primer + bond + laser); and LA (laser + acid etching + primer + bond). A standard composite resin cylinder (Z100-3M) was bonded to the dentinal surface and the SBS performed on an Instron machine (500 Kg load cell at 0.5 mm/min), followed by scanning electron microscopy (SEM) and x-ray diffraction analysis. Results: Analysis of variance (ANOVA) determined that the pretreatments influenced the SBS values (p < 0.05): AL (9.96 MPa), M (7.28 MPa), and LA (4.87 MPa), the interaction between the group and pretreatment factors also influenced the SBS (p < 0.05). The highest values were obtained for the interaction control/AL (11.64 MPa), Conclusion: the results suggested that dentin treatment with laser after the application of the adhesive system is efficient in achieving higher bond strength and is promising as a possible new adhesive substrate.

Trypanocidal activity of Brazilian plants against epimastigote forms from Y and Bolivia strains of Trypanosoma cruzi

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

Microdureza de resinas em função da cor e luz halógena

O objetivo desse trabalho foi avaliar a influência da intensidade da luz e cor de uma resina composta no grau de dureza Knoop. Corpos-de-prova foram confeccionados utilizando-se matrizes de poliéster envoltas por um anel de cobre, contendo uma cavidade padronizada de 6 mm de diâmetro por 2 mm de espessura. Estas cavidades foram preenchidas com resina composta selecionada, Fill Magic - Vigodent, com as cores A3, B3, C3, D3 e I, fotopolimerizadas através de um fotopolimerizador Elipar, calibrado para produzir 3 intensidades de luz diferentes: 450 mW/cm², 800 mW/cm² e uma intensidade de luz crescente de 100 a 800 mW/cm². Foram confeccionados 90 corpos-de-prova em que o tempo de exposição da resina à luz halógena foi de 40 s. As amostras foram armazenadas em tubos de ensaio com água destilada a 37 ± 1ºC. Após este período, foram realizados os testes de dureza Knoop na região de superfície e fundo. Os resultados mostraram que houve diferença estatística em relação a intensidade de luz, entretanto em relação a cor, não houve diferença estatística. Os autores concluíram que a cor do compósito não influencia a dureza Knoop e que a intensidade progressiva promoveu os melhores resultados de dureza Knoop.

Desempenho da colhedora de milho Penha CLM-350: parte II - sistemas de debulhamento e limpeza

Com a finalidade de quantificar o desempenho dos sistemas de debulhamento e limpeza da colhedora Penha CLM-350,, estudou-se as perdas percentuais era grão de milho, ocorridos na saída de palhas, bem como a porcentagem de impurezas, presente no milho ensacado. Tomando-se como 100% os grãos de milho colhidos pelo sistema espigador, determinou-se o valor percentual perdido pelos sistemas de debulhamento e limpeza, bem como a porcentagem de impurezas presente nos grãos de milho ensacado, nos diversos tratamentos estudados. O teor médio de umidade foi de 15,78% (b.u.). Os tratamentos correspondentes ao sistema de debulhamento e limpeza são as velocidades periféricas do debulhador ou as rotações do aspirador em faces da configuração geométrica da máquina. Os resultados obtidos foram estudados através da análise de variância, empregando-se os testes F, aos níveis de 1% e 5% de probabilidade e o teste Tukey, para a comparação estatística entre as médias. A análise estatística para verificar a influência da rotação do aspirador, era relação a porcentagem de grãos de milho perdidos na saída de palhas, mostrou diferenças altamente significativas, podendo-se admitir uma relação direta entre os dois parâmetros nas condições do ensaio. Com relação a rotação do aspirador e a porcentagem de impurezas, presentes nos grãos de milho ensacados, os testes das médias revelaram significância entre os tratamento D (1241,7 rpm) e E (820 rpm) sendo que este último apresentou a maior média. Uma análise mais acurada dos resultados sugere que a porcentagem de impurezas, estaria mais na dependência das relações de fluxo através da colhedora, do que propriamente do regime do aspirador.

Desempenho da colhedora de milho Penha CLM-350: parte III - danos mecânicos

Cm vistas a estudar o efeito do sistema de debulhamento na qualidade dos grãos de milho, realizou-se o presente trabalho, onde foram estudados os danos mecânicos sofridos pelos grãos, bem como os danos mecânicos invisíveis, evidenciados pelos testes de germinação. Nos diversos tratamentos estudados, determinou-se a porcentagem de umidade presente nos grãos de milho. Definiu-se a velocidade periférica do debulhador, pelo diâmetro (300 mm) do mesmo e as rotações, para os diversos tratamentos. O delineamento experimental foi de blocos ao acaso com 5 tratamentos e 6 repetições onde foram estudados os valores percentuais de grãos inteiros e quebrados, os teores de umidade correspondentes e os valores de germinação através da análise de variância. Empregou-se o teste F aos níveis de 1% e 5% de probabilidade e o teste Tukey para comparação entre as médias. da análise pode-se concluir que em relação ao teor de umidade dos grãos, os tratamentos não diferiram estatisticamente.

Isolation and identification of mycobacteria from livestock specimens and milk obtained in Brazil

The prevalence of Mycobacterium bovis and other mycobacterial species in livestock specimens and milk was evaluated. An emphasis was placed upon the distribution of these organisms in milk that is readily available to the public that was either untreated, pasteurized, or treated using ultra high temperature. Twenty-two pathologic specimens from livestock (bovine, swine and bubaline) in five Brazilian states and 128 bovine milk samples from retail markets in the State of São Paulo were examined for mycobacteria. Identification was made by classical biochemical tests, thin layer chromatography of mycolic acids and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Mycobacteria were isolated from 15 (68.2%) caseous lesions and from 23 (18%) milk samples. Eleven isolates were identified as M. bovis, and the remaining 27 nontuberculous mycobacterial isolates were represented by five species and six unidentified rapidly growing mycobacterial strains. The data demonstrate that animal products in Brazil are frequent reservoirs of mycobacteria and may pose a risk to the public.

Pulverização em CDA 250 herbicida pendimethalin na cultura do arroz de sequeiro

Foi estudada a viabilidade de utilização da pulverização CDA 25C, na aplicação do herbicida em pré-emergência na cultura do arroz de sequeiro. O herbicida empregado foi o pendimethalin nas doses de 0,0; 1,5; 2,0; 2,5 e 3,0 litro s/ha da formulação comercial a 50%. A pulverização convencional foi efetuada com bicos 11003 com consumo de 200 litros de calda per hectare. O processo CDA 250 foi aplicado por meio de bico rotativo (Micromax) com dois níveis de consumo de calda : 50 1/ha e 27 1/ha. Os resultados mostraram que: a) - o método CDA 250 proporciona controle dc mato e produtividade de arroz equivalentes ao método convencional; b) para o bico Micromax, a aplicação da formulação comercial de pendimethalin a 50% com vazão de 0,48 1/min./bico, a distância entre bicos deve ser de 1,75 m e para a vazão de 0,96 1/min./bloco, essa distancia deve ser de 1,90 m; c)- a aplicação do pendimethalin 50% C.E. pelo processo CDA 250, empregando 27 litros de calda por hectare foi o processo mais interessante por oferecer vantagens logísticas apreciáveis.

The compulsive-like aspect of the head dipping emission in rats with chronic electrolytic lesion in the area of the median raphe nucleus

Head dipping (HD) is a behavioral pattern considered to have a risk assessment or an exploratory role and is used as a complementary parameter to evaluate anxiety in experimental animals. Since rats with electrolytic lesion in the area of the median raphe nucleus displayed high frequencies of HD in a previous study, the present investigation was undertaken to confirm this observation and to determine its anxiety-related origin. HD episodes were counted in adult male Wistar rats (270-350 g) with electrolytic lesion (N = 11) and sham-lesioned controls (N = 12). When HD was measured for 60 min on an elevated open platform, lesioned rats emitted 13 times more HD than controls (264.7 ± 93.3 vs 20.3 ± 7.6 episodes), with the difference being statistically significant (P < 0.05). HD counts during 10-min sessions held 7, 14, 21, 27, and 63 days after lesion showed significantly higher means (range: 28.14 ± 5.38 to 62.85 ± 9.48) compared to sham-lesioned controls (range: 7.37 ± 1.13 to 8.5 ± 1.45). Normal rats stepped down into their home cages when the vertical distance between them and the cage was short (16 cm), and the step-down latencies increased with increasing depths (36.7 ± 7.92 to 185.87 ± 35.44 s). Lesioned rats showed a similar behavior when facing the shortest depth, but had a significantly increased number (23.28 ± 2.35 episodes) and latency (300 ± 0.00 s) of HD compared to normal rats (9.25 ± 1.37 episodes and 185.87 ± 35.44 s) when facing the greatest depth (30 cm). This suggests that HD may be a depth-measuring behavior related to risk assessment.