Avaliação da intensidade da luz dos aparelhos fotopolimerizadores utilizados em clínicas odontológicas de São Luís - MA / Light intensity evaluation of light curing units used in dental clinics of São Luís - Maranhão

Introdução: O aparelho fotopolimerizador é um instrumento imprescindível para garantir o sucesso das restaurações estéticas. Por isso, o controle da correta emissão de intensidade luminosa suficiente é fundamental. Entretanto, as unidades fotoativadoras são suscetíveis à perda de rendimento ao longo do tempo. Objetivo: Avaliar a intensidade luminosa emitida, o tipo de luz, o tempo de polimerização e a frequência de manutenção dos aparelhos fotopolimerizadores utilizados nas clínicas Odontológicas de São Luís-MA. Método: Foi aplicado um questionário a 148 clínicas odontológicas. Após o preenchimento do questionário foram realizadas as leituras de intensidade de luz dos aparelhos fotopolimerizadores das clínicas estudadas. A intensidade de luz foi mensurada com um radiômetro Demetron (Kerr-Sybron Dental, EUA). Resultado: Mais de 90% dos aparelhos fotopolimerizadores não se encontram em condições adequadas de emissão de luz. A grande maioria dos profissionais adota aparelho com LED (sigla do inglês Light Emission Diode ou Diodo emissor de luz) como fonte de luz para a polimerização dos materiais resinosos. Os resultados sugerem que há um desconhecimento no tempo necessário para a fotoativação e nos cuidados com a manutenção e que esses aparelhos necessitam de uma revisão periódica por parte do profissional. Conclusão: Os resultados encontrados nesta pesquisa foram considerados preocupantes. Um programa de manutenção e esclarecimento deveria ser aplicado.Palavras-chave: Clínica Odontológica. Fotopolimerização. Manutenção.AbstractIntroduction: Curing light unit is an essential instrument to ensure the success of esthetic restorations. Therefore, the control of correct emission of sufficient light intensity is critical. However, the light activating units are susceptible to lose performance over time. Objective: To evaluate the light intensity, the light type, the curing light time and the maintenance frequency of the light curing units used in dental clinics of São Luís – MA. Methods: We used a questionnaire in 148 dental clinics. After applying the questionnaires in the selected clinics, light intensity of light curing units was measured with a Demetron radiometer (Kerr, Sybron Dental, USA). Results: More than 90% of the light curing units were not with good light emission conditions. Most of the professionals use LED as the light source for polymerization of resin materials. The results suggest that dentists are not well informed about the light curing time and the light curing units maintenance. Besides, the equipments demand a periodic examination by professionals. Conclusion: Regarding the worrying findings, maintenance and clarification procedures should be applied.Keywords: Dental clinics. Light-curing. Maintenanc

Efeitos de métodos para envelhecimento na microinfiltração de um sistema adesivo usado como selante em superfícies contaminadas

This study evaluated the effects of aging methods on the microleakage of an adhesive system used for sealing pit and fissure surfaces. After acid etching, the occlusal surfaces of 60 permanent teeth were contaminated with 1mL of human plasma and then sealed with OptiBond dual cure, activated in the ramp mode (Optilux 501). The sample was then divided into eight experimental and a control groups. Aging was performed for 20 days in 5, 37, 55 and 5-55ºC (200 cycles/day) under water contact or not. After subjecting the specimens to the AgNO3 technique, they were sectioned twice. Dye penetration was measured and the mean values were subjected to ANOVA. No group provided hermetic seal against dye penetration, even the control group (without treatment). Significant aging x water interaction effect (p=0.033) was observed. The group without water contact at 5ºC (p=0.015) showed the least dye penetration value. The results led to the main conclusions: 1) all groups showed dye penetration, even the control group; 2) storage teeth at 5ºC on dry condition provided the lowest degree of dye penetration; 3) in the presence of water, the temperature variations seem not to affect the microleakage values.Este estudo avaliou os efeitos de métodos para envelhecimento na microinfiltração de um sistema adesivo usado para selar superfícies oclusais. Após o condicionamento com ácido, as superfícies de 60 dentes permanentes foram contaminadas com 1 mL de plasma e seladas com OptiBond dual cure, ativado pelo Optilux 501, no modo rampa. A amostra foi dividida em oito grupos experimentais e um grupo controle ou imediato O envelhecimento dos espécimes foi realizado por 20 dias a 5, 37, 55 e 5-55°C (200 ciclos/dia) em contato com a água ou não. Após submeter os espécimes à técnica de infiltração com AgNO3, eles foram secionados duas vezes e os valores médios da penetração do corante foram tratados por análise de variância. Nenhum grupo apresentou vedamento hermético na interface, nem mesmo o grupo sem envelhecimento (imediato ou controle). O grupo que permaneceu a 5°C sem contato com a água mostrou o menor grau de penetração (p=0,015) e a interação envelhecimento x água foi significante (p=0,033). Os resultados levam às seguintes conclusões: 1) todos os grupos mostram microinfiltração, inclusive o controle; 2) o grupo mantido a 5ºC sem contato com a água mostrou os menores valores de microinfiltração; 3) em contato com a água, as variações térmicas parecem não afetar o grau de penetração do corante

Characterization of aqueous silver nitrate solutions for leakage tests

OBJECTIVE: To determine the pH over a period of 168 h and the ionic silver content in various concentrations and post-preparation times of aqueous silver nitrate solutions. Also, the possible effects of these factors on microleakage test in adhesive/resin restorations in primary and permanent teeth were evaluated. MATERIAL AND METHODS: A digital pHmeter was used for measuring the pH of the solutions prepared with three types of water (purified, deionized or distilled) and three brands of silver nitrate salt (Merck, Synth or Cennabras) at 0, 1, 2, 24, 48, 72, 96 and 168 h after preparation, and storage in transparent or dark bottles. Ionic silver was assayed according to the post-preparation times (2, 24, 48, 72, 96, 168 h) and concentrations (1, 5, 25, 50%) of solutions by atomic emission spectrometry. For each sample of each condition, three readings were obtained for calculating the mean value. Class V cavities were prepared with enamel margins on primary and permanent teeth and restored with the adhesive systems OptiBond FL or OptiBond SOLO Plus SE and the composite resin Filtek Z-250. After nail polish coverage, the permanent teeth were immersed in 25% or 50% AgNO3 solution and the primary teeth in 5% or 50% AgNO3 solutions for microleakage evaluation. ANOVA and the Tukey's test were used for data analyses (α=5%). RESULTS: The mean pH of the solutions ranged from neutral to alkaline (7.9±2.2 to 11.8±0.9). Mean ionic silver content differed depending on the concentration of the solution (4.75±0.5 to 293±15.3 ppm). In the microleakage test, significant difference was only observed for the adhesive system factor (p=0.000). CONCLUSIONS: Under the tested experimental conditions and based on the obtained results, it may be concluded that the aqueous AgNO3 solutions: have neutral/alkaline pH and service life of up to 168 h; the level of ionic silver is proportional to the concentration of the solution; even at 5% concentration, the solutions were capable of indicating loss of marginal seal in the composite restorations; the 3-step conventional adhesive system had better performance regarding microleakage in enamel on primary and permanent teeth.FAPESPCNPqCAPES - PQ

Calcium Pre-Rinse : effect on permeability of dentin tubules by fluoride rinse

The aim of this study was to evaluate whether calcium (CaL) solution would enhance the capacity of sodium fluoride (NaF) solution in reducing the permeability of hypersensitive dentin. Thirty-two Wistar rats ingested for 45 days acidic isotonic drink (Gatorade, pH 2.7) ad libitum to induce dental erosion. Then, molar teeth received a cold stimulus to confirm the presence and score the intensity of dentin hypersensitivity based on body contraction and noise. Animals were allocated to four groups (n=8), according to the solution(s) applied in the oral cavity: NaF (12 mmol/L, 1 min); CaL (150 mmol/L, 1 min); CaL followed by NaF (CaF+NaF, 1 min each); distilled water (DW, 1 min, as negative control). The animals were euthanized and the mandibles dissected into hemimandibles, which were sealed with sticky wax, except for the occlusal surface of the molar teeth. The samples were immersed in 10% copper sulphate solution and in 1% dithioxamide alcoholic solution (25 min each). The samples were sectioned longitudinally and imaged under optical microscope. Then, dentin permeability was measured as the area of copper ion penetration, using ImageJ software. Photomicrographs were obtained by scanning electron microscopy. 68.7% of animals had body contraction associated or not with noise. One-way ANOVA followed by Tukey´s test indicated that groups treated with NaF solution, whether or not preceded by CaL solution, presented lower permeability than the remaining groups [CaL+NaF: 3405.7 ?m2 (±1796.4); NaF: 4111.7 ?m2 (±2450.6); CaL: 42254.6 ?m2 (±30399.2); DW: 37064.6 ?m2 (±21994.4)]. Photomicrographs showed that CaL+NaF group presented an increased proportion of occluded dentin tubules in comparison to the NaF-only group. Although qualitatively there seems to be a benefit in using CaL pre-rinse, this solution did not quantitatively enhance the capacity of NaF in reducing permeability of hypersensitive dentin

estudos artísticos

Há cegueira nos pintores? A escuta e revisitação dos trabalhos que nos antecedem permite acrescentar riqueza ao presente e ao alargar as opções para as intervenções do futuro. Este é um desígnio que nos importa onde a educação artística se entrecruza com a história da arte, na perspetiva de um passado que aos criadores é uma parte do seu corpo. A arte significa-se e ressignifica-se a cada resgate de uma obra perdida, a cada descoberta de um autor menos conhecido. Há capítulos que se reabrem depois da publicação alargada de um corpus desconhecido – veja-se o caso de Claude Cahun (Doy, 2007), que possibilitou um novo entendimento dos temas de género e da autorrepresentação na arte contemporânea. Esta é uma opção de resgate, de reconhecimento, para procurar sentidos desconhecidos ou mais ou menos esquecidos. Também é uma opção que experimenta a reflexão mais demorada, recusando a política fast fashion de alguns sectores que tomam as artes como um dos apartados da secção de tendências. As obras pedem maturação, tempo para produzir efeito, latência para uma disseminação eficiente. É este o sentido dos 17 artigos selecionados para o número 7 da Revista Gama, estudos artísticos: dar a conhecer, pela voz dos próprios agentes criadores, obras e autores que é preciso visitar, reaprender, reconhecer. Reuniram-se aqui algumas possibilidades de reconhecimento, autores desconhecidos, obras agora reveladas, inéditos que são divulgados. Lança-se pontes para conhecer o percurso de autores como Villari Herrmann, Edgard da Rocha Miranda, Raymonde Carasco, Armínio Kaiser, António Alfredo, Roberto Rodrigues, entre outros autores e outras obras. Após o livro de Júlio Pomar (1986) Da cegueira dos pintores, encontramos uma justificação da Revista Gama: lançar o olhar de artistas, um olhar plástico, operativo, sobre as obras de outros artistas, para um retomar do seu conhecimento.info:eu-repo/semantics/publishedVersio

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good