Are different generations of CAD/CAM milling machines capable to produce restorations with similar quality?

Background: Different CAD/CAM machinesâ generation may impact the restoration overall quality. The present study evaluated the marginal fit of CAD/CAM restorations manufactured with different generations of CEREC milling unit systems. Material and Methods: Sixteen typodont teeth were divided into two groups (n=8) according to the machineâ s generation assigned. These are control group (G1): Cerec AC with Bluecam/Cerec 3 milling unit and (G2): Cerec AC with Bluecam/MC XL Premium Package milling unit. Scanning of the preparation were performed and crowns were milled using the Vita Mark II blocks. Blocks were cemented using epoxy glue on the pulpal floor only and finger pressure applied for 1 min. Upon completion of the cementation step, misfits between the restoration and abutment were measured by microphotography and the silicone replica technique using light body silicon material on Mesial (M) and Distal (D) surfaces. Results: Mean and SDs of marginal gaps in micrometers were: G1/M: 94.90 (±38.52), G1/D: 88.53 (±44.87), G2/M: 85.65 (±29.89), G2/D: 95.28 (±28.13). Two-way ANOVA indicated no significant differences among different groups (P>0.05); surface area (P>0.05) and the interaction (P>0.05). Overall, G2 had greater margin gaps than G1, however, without statistical difference (P>0.05). Conclusions: Difference in milling unit generation did not significantly affect the marginal fit. Marginal gap means were in the range of the clinical acceptance levels for both generations of Cerec milling units, regardless the teeth site area

Mechanical properties and DIC analyses of CAD/CAM materials

This study compared two well-known computer-aided-design/computer-aided-manufactured (CAD/CAM) blocks (Paradigm MZ100 [3M ESPE] and Vitablocs Mark II [Vita] in terms of fracture toughness (Kic), index of brittleness (BI) and stress/strain distributions. Three-point bending test was used to calculate the fracture toughness, and the relationship between the Kic and the Vickers hardness was used to calculate the index of brittleness. Additionally, digital image correlation (DIC) was used to analyze the stress/strain distribution on both materials. The values for fracture toughness obtained under three-point bending were 1.87Pa√m (±0.69) for Paradigm MZ100 and 1.18Pa√m (±0.17) for Vitablocs Mark II. For the index of brittleness, the values for Paradigm and Vitablocs were 73.13μm-1/2 (±30.72) and 550.22μm-1/2 (±82.46). One-way ANOVA was performed to find differences (α=0.05) and detected deviation between the stress/strain distributions on both materials. Both CAD/CAM materials tested presented similar fracture toughness, but, different strain/stress distributions. Both materials may perform similarly when used in CAD/CAM restorations

Evaluation of mineral content in healthy permanent human enamel by Raman spectroscopy

An understanding of tooth enamel mineral content using a clinically viable method is essential since variations in mineralization may serve as an early precursor of a dental health issues, and may predict progression and architecture of decay in addition to assessing the success and effectiveness of the remineralization strategies. Twenty two human incisor teeth were obtained in compliance with the NIH guidelines and site specifically imaged with Raman microscope. The front portion of the teeth was divided into apical, medium and cervical regions and subsequently imaged with Raman microscope in these three locations. Measured mineralization levels have varied substantially depending on the regions. It was also observed that, the cervical enamel is the least mineralization as a populational average. Enamel mineralization is affected by a many factors such as are poor oral hygiene, alcohol consumption and high intake of dietary carbohydrates, however the net effect manifests as overall mineral content of the enamel. Thus an early identification of the individual with overall low mineral content of the enamel may be a valuable screening tool in determining a group with much higher than average caries risk, allowing intervention before development of caries. Clinically applicable non-invasive techniques that can quantify mineral content, such as Raman analysis, would help answer whether or not mineralization is associated with caries risk

Nutritional Profile of Patients in Hemodialysis of the Hospital Universitário Ciências Médicas - Minas Gerais

Objectives: To evaluate the nutritional status of hemodialysis (HD) patients. Methods: A cross-sectional study was performed in all patients on HD at a single center. Results: We studied 72 patients, male (57%) and 45.8% between 45 and 64 years old. The most frequent etiology was systemic arterial hypertension (50.0%) and diabetes (20.8%). KT/V  > 1.2 was found in 88.8% of the patients, and phosphorus level > 5.5 mg/dL in 25%. The malnourished patients classified by body mass index (BMI) < 25 kg/m2 (66.67%), arm muscle circumference (WBC) index (84.72%) and albumin (≤ 4.0 g/dL) (28,8%), and 22,22% use a specific oral nutritional supplement for hypercaloric hyperproteic dialytic patients, provided by the hemodialysis service. The mean interdialytic weight gain (GPIDm) was < 2.5kg in 58.3% and the relative interdialytic weight gain (GPIDr) was < 4.5% in 75.0% of the patients. There was a significant association between GPIDm and CMB, patients with lower GPIDm (≤ 2.5 kg) tended to have more mild or moderate malnutrition (p = 0.003). No differences were observed by time in hemodialysis in relation to age, interdialytic weight gain, laboratory and anthropometric measurements. Conclusion: The nutritional assessment by BMI was in agreement with the Brazilian literature. By CMB, most were classified as malnourished, which differs from albumin, in that only ∼ 30% were malnourished. The results show the importance of supplementation for this population. We have seen that > 75% of the patients are within the ideal GPIDr (< 4.5% of the dry weight). The dialysis time did not affect the nutritional evaluation parameters

Effects of Euterpe oleracea Mart. (AÇAÍ) extract in acute lung inflammation induced by cigarette smoke in the mouse

AbstractShort term inhalation of cigarette smoke (CS) induces significant lung inflammation due to an imbalance of oxidant/antioxidant mechanisms. Açai fruit (Euterpe oleracea) has significant antioxidant and anti-inflammatory actions. The present study aimed to determine whether oral administration of an açai stone extract (ASE) could reduce lung inflammation induced by CS. Thirty C57BL/6 mice were assigned to three groups (n=10 each): the Control+A group was exposed to ambient air and treated orally with ASE 300mg/kg/day; the CS group was exposed to smoke from 6 cigarettes per day for 5 days; and the CS+A group was exposed to smoke from 6 cigarettes per day for 5 days and treated orally with ASE (300mg/kg/day). On day 6, all mice were sacrificed. After bronchoalveolar lavage, the lungs were removed for histological and biochemical analyses. The CS group exhibited increases in alveolar macrophage (AMs) and neutrophil numbers (PMNs), myeloperoxidase (MPO), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase activities (GPx), TNF-α expression, and nitrites levels in lung tissue when compared with the control ones (p<0.001 for all parameters). The AMs, PMNs, MPO, SOD, CAT, GPx and nitrite were significantly reduced by oral administration of ASE when compared with CS group (p<0.001 for all parameters, with exception of AMs p<0.01). The present results suggested that systemic administration of an ASE extract could reduce the inflammatory and oxidant actions of CS. Thus, the results of this study in mice should stimulate future studies on ASE as a potential agent to protect against CS-induced inflammation in humans

O ensino de matemática no ensino fundamental anos finais sob a luz da BNCC: métodos e práticas pedagógicas / Teaching mathematics in the final years of elementary school in light of the BNCC: methods and pedagogical practices

O presente artigo foi organizado, a partir da análise da Base Nacional Comum Curricular – BNCC, com a finalidade de fazer algumas reflexões sobre o ensino de Matemática nos Anos Finais do Ensino Fundamental, ações pedagógicas a partir das competências e habilidades a serem desenvolvidas, baseadas nas diretrizes do letramento Matemático, do raciocínio lógico e desenvolvimento do senso crítico dos discentes para atuação transformadora de sua realidade. De acordo com o documento que define as aprendizagens essenciais a serem garantidas a todos os estudantes. Trata – se, portanto, de uma pesquisa qualitativa, de natureza bibliográfica, cujo arcabouço de análise foi a BNCC. O texto conclui que, além da organização das habilidades por competências, o documento valoriza também os pressupostos pedagógicos de aprendizagem a partir da sistematização das unidades temáticas, objetos de conhecimento e estratégias de ensino articuladas com experiências vividas no convívio na sociedade. Garantindo níveis de aprendizagens seriadas ao desenvolvimento das competências e habilidades relativas aos seus processos de reflexão e abstração

Energia renovável e impactos ambientais: construindo conhecimento sobre energia eólica com os estudantes do Ensino Médio em uma disciplina eletiva: Renewable energy and environmental impacts: building knowledge about wind energy with high School Students in an elective subject

O presente artigo apresenta uma fonte de energia renovável, a energia eólica, considerada um tipo de energia alternativa que atende as demandas da sociedade, garantindo uma produção de qualidade, assim como, uma redução aos impactos socioambientais decorrentes da geração e o consumo de eletricidade. A energia eólica aborda conceitos físicos relacionados à aplicação de energia cinética dos ventos no aproveitamento para geração de energia elétrica. As energias renováveis, em geral, vêm cada vez mais sendo utilizada pela sociedade em todo o mundo, deste modo, esta fonte de energia alternativa cresce constantemente devido a sua importância na contribuição de geração de energia limpa inesgotável. Assim, com o intuito de contribuir com o debate sobre esta temática, o trabalho desenvolvido teve o objetivo de apresentar o uso da energia eólica e seu potencial energético, explicando todo processo de distribuição e geração de eletricidade através de uma maquete que foi dimensionada, construída e apresentada pelos alunos de uma disciplina eletiva em Centro Educa Mais, escola de tempo integral. Trata-se de uma pesquisa descritiva, de natureza qualitativa, acerca do projeto desenvolvido em uma disciplina eletiva, realizada com os alunos do ensino médio, mais precisamente com as 1ª e 2ª séries, trabalhando a abordagem e o universo de significados que busca explicar a dinâmica das relações sociais e as percepções dos sujeitos e da situação investigada. Considerando o maior número de informações, tornando explícito o assunto investigado, foi aplicado à luz da Teoria da Aprendizagem Significativa de Ausubel (1963), Metodologia Ativa, com o aluno sendo o centro do objeto do processo de ensino-aprendizagem, aprendendo a fazer fazendo, protagonistas e autônomos com a consolidação do processo de conscientização de uma sociedade sustentável

Purification of a lectin from Cratylia mollis crude extract seed by a single step PEG/phosphate aqueous two-phase system

The partitioning and purification of lectins from the crude extract of Cratylia mollis seeds (Cramoll 1,4) was investigated in aqueous two-phase systems (ATPS). A factorial design model (24) was used to evaluate the influence of polyethylene glycol (PEG) molar mass (15008000g/mol), PEG concentration (12.517.5% w/w), phosphate (1015% w/w) concentration, and pH (68) on the differential partitioning, purification factor, and yield of the lectin. Polymer and salt concentration were the most important variables affecting partition of lectin and used to find optimum purification factor by experimental BoxBehnken design together with the response surface methodology (RSM). ATPS showed best conditions composed by 13.9% PEG1500, 15.3% phosphate buffer at pH 6, which ensured purification factor of 4.70. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis showed a single band of protein with 26.1kDa. Furthermore, results demonstrated a thermostable lectin presenting activity until 60°C and lost hemagglutinating activity at 80°C. According to the obtained data it can be inferred that the ATPS optimization using RSM approach can be applied for recovery and purification of lectins.We are grateful to the following bodies for the grants awarded: CAPES (Coordination for the Improvement of Level Personnel Superior); FACEPE (Pernambuco Science and Technology Foundation): Researcher's scholarship grant: BFP-0017-5.05/18 CNPq (National Council for Scientific Development and Technological) process: 427153/2016-6 and we also thank the reviewers for their valuable comments and suggestions as these helped us to improve the manuscript.info:eu-repo/semantics/publishedVersio

Updated cardiovascular prevention guideline of the Brazilian Society of Cardiology: 2019

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