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

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

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora