71 research outputs found
TiF4 varnish protects the retention of brackets to enamel after in vitro mild erosive challenge
The effect of fluoride agents on the retention of orthodontic brackets to enamel under erosive challenge is little investigated. Objective: The aim of this study was to evaluate the effect of titanium tetrafluoride (TiF4) and sodium fluoride (NaF) agents on the shear bond strength of brackets to enamel and on the enamel microhardness around brackets under erosive challenge. Methods: Brackets were bonded to bovine incisors. Five groups were formed according to fluoride application (n=10): TiF4 varnish, TiF4 solution, NaF varnish, NaF solution and control (without application). The specimens were submitted to erosive challenge (90 s cola drink/2h artificial saliva, 4x per day for 7 days). Solutions were applied before each erosive cycle and varnishes were applied once. Vickers Microhardness (VHN) was obtained before and after all cycles of erosion and the percentage of microhardness loss was calculated. Shear bond strength, adhesive remnant index and polarized light microscopy were conducted after erosion. The data were analyzed by ANOVA, Tukey, Kruskal-Wallis and Mann-Whitney U tests (α=0.05). Results: The %VHN had no statistically significant differences among the experimental groups. However, considering the comparisons of all groups with the control group, TiF4 varnish showed the highest protection from enamel demineralization (effect size of 2.94, while the effect size for the other groups was >2.4). The TiF4 varnish group had significantly higher shear bond strength compared to other groups. There was no difference among groups for adhesive remnant index. Polarized light microscopy showed higher demineralization depth for the control group. Conclusions: Application of NaF and TiF4 agents during mild erosive challenge minimized the enamel mineral loss around brackets, however only the experimental TiF4 varnish was able to prevent the reduction of shear bond strength of brackets to enamel.
TiF 4 varnish protects the retention of brackets to enamel after in vitro mild erosive challenge
The effect of fluoride agents on the retention of orthodontic brackets to enamel under erosive challenge is little investigated. Objective: The aim of this study was to evaluate the effect of titanium tetrafluoride (TiF<i>4</i>) and sodium fluoride (NaF) agents on the shear bond strength of brackets to enamel and on the enamel microhardness around brackets under erosive challenge. Methods: Brackets were bonded to bovine incisors. Five groups were formed according to fluoride application (n=10): TiF<i>4</i> varnish, TiF<i>4</i> solution, NaF varnish, NaF solution and control (without application). The specimens were submitted to erosive challenge (90 s cola drink/2h artificial saliva, 4x per day for 7 days). Solutions were applied before each erosive cycle and varnishes were applied once. Vickers Microhardness (VHN) was obtained before and after all cycles of erosion and the percentage of microhardness loss was calculated. Shear bond strength, adhesive remnant index and polarized light microscopy were conducted after erosion. The data were analyzed by ANOVA, Tukey, Kruskal-Wallis and Mann-Whitney U tests (α=0.05). Results: The %VHN had no statistically significant differences among the experimental groups. However, considering the comparisons of all groups with the control group, TiF<i>4</i> varnish showed the highest protection from enamel demineralization (effect size of 2.94, while the effect size for the other groups was >2.4). The TiF<i>4</i> varnish group had significantly higher shear bond strength compared to other groups. There was no difference among groups for adhesive remnant index. Polarized light microscopy showed higher demineralization depth for the control group. Conclusions: Application of NaF and TiF<i>4</i> agents during mild erosive challenge minimized the enamel mineral loss around brackets, however only the experimental TiF<i>4</i> varnish was able to prevent the reduction of shear bond strength of brackets to enamel
Oral paracoccidioidomycosis in a non-endemic region from Brazil: a short case series
Although the paracoccidioidomycosis (PCM) is endemic in Brazil, the occurrence in most states from the North and Northeastern Brazil is very unusual. The aim of this study was to evaluate the clinicopathologic features of a case series of oral PCM in a non-endemic region from Brazil (Northeastern region), discussing the clinical and histopathological differential diagnoses of the oral manifestations of the disease. Between 2000 and 2017, all cases of oral PCM were retrieved from the Oral Pathology Laboratory, Universidade Federal de Pernambuco, located at Northeastern Brazil. Clinical data, such as age, gender, origin, occupation, site, symptoms, time of complaints, clinical presentation, number of lesions, and clinical hypotheses of diagnosis, were collected from the clinical charts. All cases were histologically reviewed in hematoxylin-eosin and Gomori-Grocott staining. Six cases were identified. All patients were male, with a mean age of 53.8 years (ranging from 40 to 73 years). Four cases appeared as multiple ulcers and two presented single lesions (buccal mucosa and hard palate). Clinically, in five cases, squamous cell carcinoma was considered in the differential diagnosis. The common histopathological features consisted of hyperplastic epithelium, intraepithelial microabscesses, and formation of granulomatous chronic inflammatory reaction in a fibrous connective tissue with severe chronic inflammatory reaction. Yeasts were observed either inside of multinucleated giant cells or extracellularly. Although rare in non-endemic regions, oral PCM should be considered in the differential diagnosis of oral chronic ulcers, mainly those multiple
Marketing de relacionamento como fator otimizador de vendas
“O cliente tem sempre razão”, com essa chamada, todas as organizações desenvolveram seus
planejamentos de estratégicos, planos e marketing e ou, dentre outros, essenciais para o bom
desempenho de suas atividades. Com o passar dos anos, as exigências, demandas e expectativas
dos consumidores tem sofrido grandes mudanças, seja pela qualidade dos produtos ou mesmo
pela presteza na prestação dos serviços. Dessa forma, torna-se imprescindível que o empresário
compreenda o comportamento do consumidor antes de tomar qualquer atitude, seja colocando um
produto novo no mercado ou oferecendo algum tipo de serviço. Alguns autores contemporâneos
consideram já, que todo o planejamento de suas organizações deve ser desenvolvido tendo como
uma análise profunda do comportamento do consumidor, no sentido de que ele ainda sendo a
referência principal para que a empresa oferte um novo produto no mercado. Dessa forma então, a
Empresa Engemix, busca ofertar um produto agregando um serviço bem diferenciado dos já
existente no mercado, procurando, dessa forma, oferecer um diferencial para seus clientes.info:eu-repo/semantics/publishedVersio
A voz dos bandos: colectivos de justiça e ritos da palavra portuguesa em Timor Leste colonial
Este artigo examina as relações entre o discurso da justiça e a prática do ritual nos bandos do governo colonial português em Timor Leste, entre a segunda metade do século XIX e as primeiras décadas do século XX. Os bandos consistiam em ordens e instruções de comando emanadas pelo governador português em Díli, e comunicadas de forma cerimonial por oficiais às populações dos diversos reinos timorenses dispersos pelo país. Bandos eram um instrumento por excelência de governação colonial dos assuntos indígenas, servindo para arbitrar conflitos, punir transgressões e, em geral, instituir realidades no mundo timorense. Contudo, esta instituição assumiu igualmente uma singular expressão nos usos timorenses, servindo bandos para comunicar também as ordens de autoridades tradicionais, os liurais. O artigo acompanha as variações coloniais e indígenas que os bandos adquiriram em Timor Leste, conceptualizando-os enquanto colectivos de justiça. Ao considerar assim os bandos como colectivos – formações heterogéneas em que elementos linguísticos e não linguísticos se combinam na produção de efeitos de poder sobre as populações – o artigo propõe uma via conceptual alternativa às perspectivas linguísticas e literárias de análise do discurso colonial
Os partidos dentro e fora do poder: a judicialização como resultado contingente da estratégia política
Gestão das redes e sistemas educacionais: afirmação dos direitos à vida e à educação no retorno às atividades escolares em 2021
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
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