2 research outputs found

    PROPRIEDADES MECÂNICAS DE MATERIAIS RESINOSOS UTILIZADOS PARA RESTAURAÇÕES DE LESÕES CERVICAIS / MECHANICAL PROPERTIES OF RESIN MATERIALS USED IN CERVICAL LESIONS RESTORATIONS

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    Introdução: Desordens oclusais complexas podem ocasionar a fratura de tecido dentário e o aparecimento de hipersensibilidade dentinária, levando o profissional a difícil escolha do material restaurador. Objetivo: Comparar as propriedades mecânicas (resistência flexural e módulo de elasticidade) de cinco materiais utilizados para restauração de lesões cervicais com a dentina bovina. Métodos: Foram utilizadas duas resinas compostas comerciais de baixa viscosidade: Opallis Flow (OL) e Natural Flow (NF); duas resinas composta comerciais de viscosidade média: Z-100 (Z100) e Opallis (OP); e um cimento de ionômero de vidro modificado por resina Riva Light Cure (RL). Para a confecção dos corpos-de-prova, o material foi inserido uma matriz de silicone e fotoativado (n=12). Para a confecção dos corpos-de-prova de dentina, raízes de dentes bovinos foram utilizadas. As raízes foram seccionadas em uma máquina de corte (Isomet 1000) e lixados para obtenção dos palitos de dentina (10x1x1mm). Após, os corpos-de-prova foram levados a uma máquina de ensaio universal (Instron 3342) sob uma velocidade de 0,5 mm/min para o ensaio de resistência flexural e módulo de elasticidade. Os dados foram submetidos ANOVA um fator e Tukey (α=0.05). Resultados: Houve diferença significativa entre os grupos experimentais testados (p<0,05). A dentina bovina apresentou valores superiores de resistência flexural (169,30 ± 19,60 MPa) e os menores valores de módulo de elasticidade (4,48 ± 0,32 GPa). Conclusão: Nenhum material utilizado na pesquisa apresenta características mecânicas próximas daquelas encontradas na dentina bovina.Palavras-chave: Módulo de Elasticidade. Materiais Dentários. Dentina.AbstractIntroduction: Complex occlusal disorders can lead to tissue tooth fracture and may cause dentin hypersensitivity, thus dental professional have difficult to choose the ideal restorative material Objective: To compare flexural strength and modulus of elasticity, of five materials used for restoration of cervical lesions with bovine dentin. Methods: Two low viscosity resins: Opallis Flow (OL) and Natural Flow (NF), two medium viscosity resins: Z-100 (Z100) and Opallis (OP), and ionomer resin modified glass Riva Light Cure (RL) were tested materials. The specimens were made by silicon matrix and halogen light curing unit (Optilux 501) (n = 12). For dentin specimens, twelve bovine teeth without coronal portion were used. The roots were cut using a cutting machine (Isomet 1000) to obtain dentin sticks (10x1x1mm). Flexural strength test was conducted on a universal testing machine (Instron 3342) at a crosshead speed of 0.5 mm/min. Data were submmited to ANOVA (one variation factor) and Tukey (α=0.05). Results: There were significant differences between experimental groups tested (p < 0.05). Bovine dentin showed higher flexural strength values, which were statistically significant (169.30 ± 19.60 MPa). Bovine dentin showed lower modulus values (4.48 ± 0.32 GPa). Conclusion: No material used in this study showed similar mechanical properties from those found in bovine dentin.Keywords: Elastic Modulus. Dental Materials. Dentin

    ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

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    Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ
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