In situ effect of an erosive challenge on different restorative materials and on enamel adjacent to these materials

Objectives: This in situ study evaluated the effect of an erosive challenge on different restorative materials and on enamel restored with these materials, as well as the ability of these materials to protect the adjacent enamel against erosion.Methods: Ten volunteers wore palatal devices with eight bovine enamel blocks, randomly selected and distributed into two vertical rows, corresponding to the following groups: GI/GV, resin-modified glass ionomer; GII/GVI, conventional glass ionomer; GIII/GVII, composite resin; GIV/GVIII, amalgam. one row (corresponding to groups I-IV) was immersed in a cola drink and the other row (corresponding to groups V-VIII) was subjected to saliva only. The palatal device was continuously worn for 7 days and only half of the appliance (groups I-IV) was immersed in the soft drink (Coca-Cola (R), 150 mL) for 5 min, three times a day. The study variables comprised the wear (profilometry, mu m) and the percentage of surface microhardness change (%SMHC). Data were tested for significant differences by two-way ANOVA and Tukey's tests (p < 0.05).Results: Considering the restorative materials, for %SMHC and wear, there were no differences among the materials and between the saliva and the erosive challenge. For enamel analyses, the erosive challenge promoted a higher wear and %SMHC of the enamel than did the saliva. There were no significant differences in wear and %SMHC of the enamel adjacent to the different restorative materials.Conclusion: This research data suggest that there is little %SMHC and wear of the studied restorative materials and none of them had a preventive effect against erosion on adjacent enamel, which showed a pronounced wear. (c) 2007 Elsevier Ltd. All rights reserved.

Effect of light-curing units on microleakage under dental composite resins

The aim of this study was to determine the effect of two light-curing units (QTH and LED) on microleakage of Class II composite resin restorations with dentin cavosurface margins. Twenty extracted mandibular first premolars, free of caries and fractures were prepared two vertical slot cavities in the occluso-mesial and -destal surfaces (2 mm buccal-lingually, 2 mm proximal-axially and cervical limit in enamel) and divided into 4 equal groups (n = 8): GI and GII: packable posterior composite light-activated with LED and QTH, respectively; GIII and GIV: micro-hybrid composite resin light-activated with LED and QTH, respectively. The composite resins were applied following the manufacturer's instructions. After 24 h of water storage specimens were subjected to thermocycling for a total of 500 cycles at 5 and 55A degrees C and the teeth were then sealed with impermeable material. Teeth were immersed in 0.5% Basic fuchsin during 24 h at room temperature, and zero to three levels of penetration score were attributed. The Mann-Whitney and Kruskal-Wallis tests showed significant statistically similar (P > 0.05) from GI to GII and GIII to GIV, which the GII (2.750) had the highest mean scores and the GIII and GIV (0.875) had lowest mean scores. The use of different light-curing units has no influence on marginal integrity of Class II composite resin restorations and the proprieties of composite resins are important to reduce the microleakage.

Temperature and water content influence on thermophysical properties of coffee extract

Specific heat, thermal conductivity, thermal diffusivity, and density of coffee extract were experimentally determined in the range of 0.49 to 0.90 (wet basis) water content and at temperatures varying from 30 to 82 degreesC. Thermal conductivity and specific heat were measured by means of the same apparatus- a cell constituted of two concentric cylinders - operating at steady and unsteady state, respectively. The thermal diffusivity was measured by the well-known Dickerson's method and density was determined by picnometry. The results obtained were used to derive mathematical models for predicting these properties as a function of concentration and temperature.

Ativação muscular do quadril e do joelho em duas aterrissagens realizadas por atletas do sexo masculino

OBJETIVO: Comparar a atividade muscular antes e após o contato com o solo entre as aterrissagens unilateral (AU) e bilateral (AB) em atletas do sexo masculino. PARTICIPANTES: Quinze atletas masculinos de voleibol sem sinais e sintomas de lesões nas extremidades inferiores (13 ± 1 ano, 1,70 ± 0,12m, 60 ± 12kg). MENSURAÇÕES:Os participantes realizaram dois saltos verticais, aterrissando unilateralmente e bilateralmente. A atividade mioelétrica do reto femoral (RF), bíceps femoral (BF), adutores de quadril (AQ) e a relação BF/RF foram comparados entre as duas aterrissagens e entre as fases caracterizadas por 100ms antes (PRE) e 100ms após (POS) o contato com o solo. RESULTADOS: Em ambas as aterrissagens, a ativação do RF foi maior na fase POS em relação à PRE. Na comparação entre as aterrissagens dentro da mesma fase não encontramos diferenças estatísticas. Apesar de o BF não ter apresentado diferenças entre as fases PRE e POS em cada aterrissagem, sua ativação foi maior na AU. Os AQ apresentaram maior ativação na fase POS durante a AU, no entanto não houve diferenças quando comparadas as duas aterrissagens. A relação BF/RF apresentou valores maiores em ambas as aterrissagens na fase PRE. No entanto, não encontramos diferenças entre as aterrissagens. CONCLUSÃO: Os resultados sugerem que cada músculo apresenta um papel diferente durante a fase de aterrissagem em homens. Enquanto que o RF possui como principal função a frenagem da articulação do joelho e do movimento descendente, caracterizada pelo aumento da ativação na fase pós-contato, o BF parece atenuar a tensão articular do joelho em atividades de maior impacto, mantendo-se mais ativo durante todo o ciclo da AU. Já a maior ativação dos AQ após o contato com solo na AU evidencia a importância da região lombo-pélvica na estabilização pélvica em situações de grande instabilidade. Estudos futuros são necessários para determinar os efeitos da ativação muscular apresentada na imposição de cargas mecânicas potencialmente lesivas no joelho em atletas do sexo masculino.

Tilted and Short Implants Supporting Fixed Prosthesis in an Atrophic Maxilla: A 3D-FEA Biomechanical Evaluation

Purpose: This study compared the biomechanical behavior of tilted long implant and vertical short implants to support fixed prosthesis in an atrophic maxilla. Materials and Methods: The maxilla model was built based on a tomographic image of the patient. Implant models were based on micro-computer tomography imaging of implants. The different configurations considered were M4S, four vertical anterior implants; M4T, two mesial vertical implants and two distal tilted (45°) implants in the anterior region of the maxilla; and M6S, four vertical anterior implants and two vertical posterior implants. Numerical simulation was carried out under bilateral 150N loads applied in the cantilever region in axial (L1) and oblique (45°) (L2) direction. Bone was analyzed using the maximum and minimum principal stress (σmax and σmin), and von Mises stress (σvM) assessments. Implants were analyzed using the σvM. Results: The higher σmax was observed at: M4T, followed by M6S/L1, M6S/L2, M4S/L2, and M4S/L1 and the higher σvM: M4T/L1, M4T/L2 and M4S/L2, M6S/L2, M4S/L1, and M6S/L1. Conclusions: The presence of distal tilted (all-on-four) and distal short implants (all-on-six) resulted in higher stresses in both situations in the maxillary bone in comparison to the presence of vertical implants (all-on-four). © 2013 Wiley Periodicals, Inc.

Influência do número e inclinação dos implantes para a ancoragem de prótese fixa em maxila atrófica: estudo comparativo com elementos finitos 3D

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação in vitro das microdeformações em implantes curtos, com conexão protética cone morse e diferentes desenhos de roscas, convencionais e platôs

Pós-graduação em Odontologia Restauradora - ICT

Tratamento de recessões gengivais múltiplas: uma abordagem mais conservadora

Periodontal therapy has undergone significant changes in recent decades. While in the past the only goal was to restore gingival health, with no concern about the possible consequences of the disease treatment, currently the procedures are performed in a less invasive manner, to maintain aesthetic periodontal results or even recover them. Gingival recession is an alteration frequently found in patients and may be a complaint for causing various complications. For their treatment, several surgical techniques are reported in the literature. The techniques that are more predictable are those that associate a subepithelial connective tissue graft and a coronally repositioned flap. The original technique consists in performing two vertical incisions for an extensive release of the flap and its stabilization in a coronal position. Although this procedure is extremely widespread in the literature, the search for less invasive surgeries without the use of vertical incisions are the current aim of periodontal plastic surgeries, since they present several advantages. The aim of this paper is to demonstrate a case where adjacent, deep and multiple recessions were present resulting in aesthetic problems, which was resolved by a less invasive approach using a surgical technique in envelope and a subepithelial connective tissue graft.

Vertical distribution of benthic invertebrate larvae during an upwelling event along a transect off the tropical Brazilian continental margin

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

Flutuação populacional e distribuição vertical de Brevicoryne brassicae (L.) (Hemiptera: Aphididae) em couve

O conhecimento da dinâmica populacional e da distribuição vertical de insetos pragas em plantas hospedeiras é fundamental para o desenvolvimento de programas de manejo integrado de pragas. No presente trabalho efetuou-se um levantamento populacional de formas ápteras do pulgão Brevicoryne brassicae (L.), visando determinar a época de maior densidade populacional e a distribuição vertical em plantas de couve, (Brassica oleracea L. var. acephala DC.), cultivadas em Jaboticabal, SP. O estudo foi realizado durante as safras de brássicas de 1998 e 1999, efetuando-se correção da acidez do solo por meio de aplicação de calcário apenas no campo utilizado em 1998. A amostragem dos pulgões foi feita visualmente em folhas classificadas em três categorias: apical, mediana e basal. Nas duas safras estudadas, a infestação de B. brassicae na couve atingiu a maior densidade populacional em setembro, diminuindo rapidamente a seguir. Nos dois campos não se observou a mesma distribuição de B. brassicae em folhas apicais, medianas e basais. Os fatores que podem ter contribuído para as diferenças observadas no padrão de distribuição do pulgão devem estar relacionados com a precipitação pluvial e o calcário magnesiano.

Vertical growth of mini watermelon according to the training height and plant density

A melancia é uma espécie tradicionalmente conduzida em campo no sistema rasteiro. As cultivares de frutos pequenos (1 a 3 kg), que adquirem melhores preços de mercado, vêm sendo cultivadas também em ambiente protegido, onde são conduzidas no sistema vertical, com poda de ramos e raleio de frutos. Essas práticas possibilitam aumentar o adensamento das plantas, a qualidade e a produtividade de frutos em comparação ao sistema rasteiro. Objetivou-se com este trabalho avaliar a influência de três alturas de condução (1,7; 2,2 e 2,7 m) e duas densidades de plantas (3,17 e 4,76 plantas m-2) sobre as características produtivas e qualitativas da mini melancia Smile cultivada em ambiente protegido. A poda da haste principal foi realizada aos 43, 55 e 66 dias após o transplante (DAT) para as alturas de condução de 1,7; 2,2 e 2,7 m, respectivamente. A massa seca dos ramos, dos pecíolos, das folhas e total foram afetados pela altura de condução, cujos maiores valores foram obtidos para as plantas conduzidas a 2,2 e 2,7 m de altura. A área foliar, a área foliar específica e o índice de área foliar não foram influenciados pela altura de condução das plantas. A altura de condução de 2,7 m elevou a produtividade total. Entretanto, a produtividade comercial, a massa média dos frutos e todas as características qualitativas não foram significativamente diferentes das obtidos pela altura de poda de 2,2 m. em relação à densidade de plantas, a melhor opção foi a de 4,76 plantas m-2, pois elevou a produtividade comercial em 37,4% sem reduzir a massa média dos frutos.

Efeito do aquecimento com corrida sobre a agilidade e a impulsão vertical em jogadores juvenis de futebol

The aim of this study was to evaluate the effect of warm-up on agility (AG) and on vertical jump (VJ) tests in youth soccer players. Sixteen players performed the AG and VJ tests without warm-up (NW) and with warm-up (WW) randomly, within two weeks, at least 48 h interval, during season. The warm-up was performed only a light running during 10 min. The paired t-test identified significant difference (p <0,05) between the NW and WW conditions in the tests of SR and CJ (9,14 +/- 0,28 vs 8,94 +/- 0,30 s e 51,4 +/- 4,2 vs 54,5 +/- 6,4 cm, respectively). The warm-up performed on light intensity running was effective to improve the AG and VJ tests performance in youth soccer players.

The Synthetic Control Chart Based on Two Sample Variances for Monitoring the Covariance Matrix

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Alternative proposal for Modal Representation of a Non-transposed Three-Phase Transmission Line with a Vertical Symmetry Plane

The objective of this paper is to show an alternative representation in time domain of a non-transposed three-phase transmission line decomposed in its exact modes by using two transformation matrices. The first matrix is Clarke's matrix that is real, frequency independent, easily represented in computational transient programs (EMTP) and separates the line into quasi-modes a, b and zero. After that, Quasi-modes a and zero are decomposed into their exact modes by using a modal transformation matrix whose elements can be synthesized in time domain through standard curve-fitting techniques. The main advantage of this alternative representation is to reduce the processing time because a frequency dependent modal transformation matrix of a three-phase line has nine elements to be represented in time domain while a modal transformation matrix of a two-phase line has only four elements. This paper shows modal decomposition process and eigenvectors of a non-transposed three-phase line with a vertical symmetry plane whose nominal voltage is 440 kV and line length is 500 km.

Calcaneal Tendon Regions Exhibit Different MMP-2 Activation After Vertical Jumping and Treadmill Running

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