Cyclic Fatigue Resistance of WaveOne Gold, ProDesign R and ProDesign Logic Files in Curved Canals In Vitro

Introduction: Endodontic instruments are developed to provide a better cleaning of the root canal system and reduce its risk of fracture. The aim of this study was to evaluate the instrumentation time and cyclic fatigue resistance of WaveOne Gold, ProDesign R and ProDesign Logic files. Methods and Materials: Thirty Nickel-titanium (NiTi) rotary instruments were divided into 3 groups (n=10). ProDesign Logic file 25/0.06 was used in continuous rotation after glide path preparation. WaveOne Gold 25/0.07 and ProDesign R 25/0.06 files were used in reciprocating motion. Every file instrumented 3 standardized artificial canals. The average time, the number of cycles (NCI) and cyclic fatigue resistance of each file were determined through the number of cycles to failure (NCF) in a stainless-steel device. The total amount of cycles to fracture was also calculated (NCI+NCF). Data was analyzed using the Kruskal-Wallis and Mann-Whitney tests. Results: The instrumentation time of the ProDesign Logic file was significantly lower when compared to the other files (P=0.019). The longest times to failure were presented by ProDesign Logic (182.07 sec) and ProDesign R (152.38 sec) files. The same differences were observed for the NCF (910.37 and 761.93). The WaveOne Gold group presented a lower NCF as well as a smaller sum of NCI+NCF (748.33) that was statistically significant when compared to the other groups (P<0.05) respectively. Conclusion: The use of continuous rotational motion in canals with a glide path in the ProDesign Logic group led to shorter instrumentation time. The cyclic fatigue resistance of ProDesign R and Logic instruments was superior to WaveOne Gold. The thermal treatment of the instrument’s alloy, its cross section and the glide path seems to influence the cyclic fatigue resistance.Keywords: Cyclic Fatigue; ProDesign Logic; ProDesign R; WaveOne Gol

Evaluation of microhardness, sorption, solubility, and color stability of bulk fill resins : a comparative study

Due to the increasing popularity of bulk fill resins, there is a concern that their components can be leached; this is because these are inserted in a single 4-5 mm increment. This in vitro study evaluated the microhardness, sorption, solubility, and color stability of three restorative bulk fill resins, namely: Filtek Bulk Fill (FBF), Tetric N-Ceram Bulk Fill (TNC), and Opus Bulk Fill (OBF). Cylindrical samples were fabricated to be 15 mm in diameter and 1 mm thick (n = 10). For the microhardness test, three random indentations were formulated on the samples using a micro-durometer with a load of 300 gf for 15 s. Sorption and solubility were then evaluated (ISO 4049: 2009). Color stability was analyzed with a digital spectrophotometer three times (initially, after 24 h, and after 7 d) during immersion in coffee and distilled water (control). The Shapiro-Wilk test was applied to analyze normality. The Mann-Whitney and Kruskal-Wallis tests were used to compare the groups and the immersion solution, with a significance level of 5%. There were a significant difference in microhardness (p<0.001), with the FBF group showing a higher value compared to the other groups (56.38). The highest average of sorption scores was observed in the OBF group (16.9 µg / mm3), followed by FBF (16.8 µg / mm3) and TNC (11.3 µg / mm3). Solubility was lowest in the OBF group (-2.83 µg / mm3), with a significant difference (p = 0.031). There was also a significant difference after 24 h in the mean ?E score of all groups (p<0.005). After one week of immersion, the group that pigmented most was OBF (p = 0.008). The three bulk fill resins had acceptable hardness, sorption, and solubility values. However, all groups showed a high pigmentation rate after 7 d of immersion in coffee

Cyclic Fatigue Resistance of Mtwo Rotary Instruments with two Different Instrumentation Techniques

Introduction: The objective of this in vitro study was to evaluate whether cervical preparation with Mtwo files in a crown-down technique influences instrumentation time and the cyclic fatigue resistance of these instruments. Methods and Materials: Two instrumentation techniques were evaluated (manufacturer and crown-down). Each group consisted of 10 kits containing four Mtwo instruments (10/0.04, 15/0.05, 20/0.06, and 25/0.06), which were used to prepare three standard simulated curved resin canals. The mean instrumentation time and the corresponding number of cycles for each instrumentation (NCI) were recorded. The instruments were rotated at a constant speed of 300 rpm in a stainless-steel canal (diameter of 1.5 mm) at a 90° angle of curvature and 5-mm radius. The center of the curvature was 5 mm from the tip of the instrument. The cyclic fatigue resistance of the files was determined by counting the number of cycles to failure (NCF). Data were analyzed by the Mann-Whitney test. Results: The mean instrumentation time and NCI of files 10/0.04 and 15/0.05 were significantly lower (P&lt;0.05) when the crown-down technique was used compared to the manufacturer’s method for the same tip size/taper file. There was no significant difference in the mean NCF between the two techniques. Conclusion: The crown-down technique did not interfere with resistance to cyclic fatigue. However, the shorter instrumentation time of files 10/0.04 and 15/0.05 could reduce the fracture risk in the case of reuse of these instruments.Keywords: Crown Down; Cycles to Failure; Cyclic Fatigue; Instrument Fracture; Root Canal Instrumentation

Effect of Reciprocating and Rotary Systems on Postoperative Pain: A Systematic Review and Meta-Analysis

Introduction: Our study aimed to compare the incidence and intensity of postoperative pain after endodontic instrumentation with reciprocating and rotary systems. Methods and Materials: An electronic literature search was performed with MEDLINE via PubMed, Scopus, and Web of Science databases from January 2008 to June 2020. Two high-impact endodontic journals were also hand searched. The selection criteria were: Population; patients requiring endodontic treatment, Intervention and Comparison; endodontic instrumentation with reciprocating versus rotary systems, and Outcome; postoperative pain. We extrapolated all included research data and reported them as dichotomized ordinal variables to evaluate the incidence of pain and continuous variables to assess pain intensity. Standardized mean difference (SMD) was calculated with Inverse Variance method for pain intensity; the incidence of postoperative pain was calculated using relative risk (RR) with the Mantel-Haenszel method. Random-effects model and 95% confidence interval (CI) were used for all meta-analyses. The I2 statistic was used to evaluate the statistical heterogeneity among studies (P&lt;0.05). Results: Twenty-one articles were selected and 17 of them were included in the meta-analysis for the evaluation of postoperative pain in the first 24h. The meta-analysis was performed in two steps: a) all studies were included; b) subsequently studies with preoperative pain were excluded. A significant difference was observed in the intensity of postoperative pain; with rotary system having more favorable in both steps [a) SMD: 0.27; 95% CI: 0.13 to 0.41; P=0.0002; b) SMD: 0.37; 95% CI: 0.15 to 0.58; P=0.0010]. There was no significant difference in the incidence of pain, and the incidence of mild, moderate and severe pain . Conclusion: The meta-analysis results revealed that rotary system were the instrument of choice as they had lower intensity of postoperative pain. Further controlled studies are advocated to provide clarification for intensity/incidence of postoperative pain in endodontic treatment with mechanized instruments

Analise das propriedades do concreto no estado fresco e endurecido com a adição de fibras de aço / Analysis of the properties of concrete in the fresh and hardened state with the addition of steel fibers

O concreto é um dos materiais mais utilizados no mundo, seu destaque se deve ao seu baixo custo e grande capacidade de adequação a variadas produções, além da possibilidade de moldar peças de acordo com a necessidade de projeto. Contudo, as fibras de aço adicionadas a esses, aumentam a resistência, ajudam a controlar a fissuração e dispõem de outras vantagens. Assim, este trabalho tem como objetivo, identificar as propriedades do concreto tanto no estado fresco como endurecido na presença e adição de fibras de aço. Qualificando-se ainda em uma pesquisa de cunho quantitativa, descritiva, explicativa e experimental para a então análise das características como trabalhabilidade, resistência, ductilidade etc. No experimento, foram moldados e rompidos 30 corpos de prova aos 28 dias de cura úmida e ensaios de resistência à tração na flexão, resistência à compressão e o slump test para todos os traços na análise do concreto no estado fresco e endurecido com a adição de fibras de aço. Os estudos realizados mostraram que o aumento da resistência é diretamente proporcional a adição de fibras de aço, sendo para esforços de tração na flexão e compressão, já a trabalhabilidade diminuía à medida que se adicionaram as fibras, tendo o menor abatimento de tronco de cone de 49 mm com ductilidade afetada positivamente pela adição. Portanto, pode-se afirmar que em quantidades adequadas, a adição das fibras é vantajosa em diversas características, bem como o aumento da resistência a compressão e a tração quando submetido a cargas elevadas, incluindo redução da fissuração

Desafios e avanços na antibioticoterapia para exacerbações pulmonares na fibrose cística

A fibrose cística é uma doença genética complexa que afeta a produção de muco e a função pulmonar. Exacerbações pulmonares, muitas vezes provocadas por Pseudomonas aeruginosa, são comuns. O diagnóstico requer testes de suor e genéticos para guiar a terapia antibiótica. Avanços com moduladores CFTR melhoram a função pulmonar, mas desafios como resistência bacteriana persistem. Este estudo busca analisar a antibioticoterapia para exacerbações pulmonares na fibrose cística, com foco em abordagens inovadoras e personalizadas. O estudo, baseado em uma revisão sistemática da literatura científica, abrange o período de 2016 a 2024, utilizando as bases de dados PubMed (Medline), Cochrane Library e Scientific Electronic Library Online (SciELO). No primeiro estudo, sobre adjuvantes antibióticos no tratamento de infecções pulmonares em pacientes com fibrose cística, não houve impacto significativo nas exacerbações pulmonares ou na função respiratória. O KB001-A não alterou o tempo para a próxima administração de antibióticos em comparação ao placebo. Evidências apontam uma possível redução na densidade de Pseudomonas aeruginosa com o KB001-A e reduções em Staphylococcus aureus e quase-Pseudomonas aeruginosa com o óxido nítrico, sem diferenças na qualidade de vida. O segundo estudo, em um modelo suíno de pneumonia por Pseudomonas aeruginosa multirresistente, a terapia inalatória de amicacina combinada com meropenem mostrou maior eficácia bactericida nas secreções traqueais em comparação à monoterapia intravenosa. A administração inalatória não preveniu a disseminação da infecção, mas a amicacina evitou o aumento da concentração inibitória mínima de meropenem, com alta concentração nas amostras sem diferenças entre pulmões infectados e não infectados. No terceiro estudo, O estudo das nanopartículas poliméricas na eliminação de biofilmes bacterianos em cepas resistentes e suscetíveis associadas à fibrose cística mostrou potencial promissor contra bactérias multirresistentes. Os nanoportadores de lipídios demonstraram eficácia terapêutica significativa, ressaltando a necessidade de mais pesquisas para confirmar seu benefício clínico. Em resumo, os adjuvantes antibióticos não impactaram significantemente o tratamento de infecções pulmonares na fibrose cística. A combinação de amicacina e meropenem foi eficaz contra pneumonia por Pseudomonas aeruginosa multirresistente. As nanopartículas poliméricas e nanoportadores de lipídios mostraram potenciais terapêuticos promissores, demandando mais pesquisas para validar seus benefícios clínicos

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Educomunicação e suas áreas de intervenção: Novos paradigmas para o diálogo intercultural

oai:omp.abpeducom.org.br:publicationFormat/1O material aqui divulgado representa, em essência, a contribuição do VII Encontro Brasileiro de Educomunicação ao V Global MIL Week, da UNESCO, ocorrido na ECA/USP, entre 3&nbsp;e 5 de novembro de 2016. Estamos diante de um conjunto de 104 papers executivos, com uma média de entre 7 e 10 páginas, cada um. Com este rico e abundante material, chegamos ao sétimo e-book publicado pela ABPEducom, em seus seis primeiros anos de existência. A especificidade desta obra é a de trazer as “Áreas de Intervenção” do campo da Educomunicação, colocando-as a serviço de uma meta essencial ao agir educomunicativo: o diálogo intercultural, trabalhado na linha do tema geral do evento internacional: Media and Information Literacy: New Paradigms for Intercultural Dialogue