Retention of oral microorganisms on conventional and resin-modified glass-ionomer cements

A cárie secundária representa problema de saúde pública e socioeconômico no mundo. A restauração de dentes acometidos por cárie pode criar condições favoráveis à proliferação microbiana na superfície do material restaurador ou na interface dente/restauração, criando ambiente propício para o estabelecimento de cárie secundária. O objetivo deste estudo foi avaliar a capacidade de retenção de placa bacteriana em cimentos de ionômero de vidro convencionais (Chelon-Fil e Vidrion R) e modificados por resina (Vitremer e Fuji II LC) e de resina composta híbrida (Z100), utilizada como controle. Nos testes de retenção de microrganismos, in situ, 12 voluntários utilizaram, por 7 dias, placa de Hawley contendo corpos-de-prova de todos os materiais. A seguir, os corpos-de-prova foram transferidos para tubos contendo 2,0 ml de Ringer-PRAS e os microrganismos presentes em sua superfície foram cultivados em placa com ágar-sangue e ágar Mitis Salivarius Bacitracina, os quais foram incubados, a 37ºC, em anaerobiose (90% N2, 10% CO2), por 10 e 2 dias, respectivamente. Os ionômeros modificados por resina retiveram quantidade de bactérias similar àquela mostrada pela resina testada. Os ionômeros modificados por resina também apresentaram menor número de estreptococos do grupo mutans do que a resina e os cimentos ionoméricos convencionais. Os ionômeros de vidro convencionais apresentaram menor número de estreptococos do grupo mutans que a resina, sendo que essa diferença não foi estatisticamente significativa.Secondary caries are a worldwide public and socioeconomic problem. The placement of restorations can lead to the development of environmental conditions favorable to microbial colonization, especially on the tooth/restoration interface, which is a predisposing factor for secondary caries. The aim of this study was to evaluate microbial retention on conventional (Chelon-Fil and Vidrion R) and resin-modified (Vitremer and Fuji II LC) glass-ionomer cements, in situ, using a hybrid composite resin (Z100) as a control. Twelve volunteers wore Hawley appliances with specimens made of all tested filling materials for 7 days. The specimens were then removed from the appliances and transferred to tubes containing 2.0 ml of Ringer-PRAS. Microorganisms from the samples were inoculated onto blood agar and Mitis Salivarius Bacitracin agar and incubated under anaerobiosis (90% N2, 10% CO2), at 37°C, for 10 and 2 days, respectively. The resin-modified glass-ionomer cements and the composite resin retained the same levels of microorganisms on their surfaces. The resin-modified glass-ionomers retained less mutans streptococci than the composite resin and conventional glass-ionomer cements. The conventional glass-ionomer cements retained less mutans streptococci than the composite resin, but that difference was not statistically significant

Fluoride release by restorative materials before and after a topical application of fluoride gel

Avaliou-se a liberação de flúor de materiais restauradores (Vitremer, Ketac-Fil, Fuji II LC e Freedom) durante 2 períodos de 15 dias, antes e após a aplicação tópica de fluorfosfato acidulado (FFA). Foram confeccionados, para cada material, 6 corpos-de-prova que foram imersos em 2 ml de água deionizada. As dosagens da concentração de flúor das soluções foram realizadas em intervalos de 24 horas durante 15 dias. Após esse período, os corpos-de-prova de cada material receberam tratamento com gel de FFA durante 4 minutos. O flúor liberado foi analisado em intervalos de 24 horas durante 15 dias. A análise de variância e o teste de Tukey (p < 0,05) mostraram que a média total de flúor liberado durante os 15 dias iniciais foram maiores para o Vitremer e o Ketac-Fil e menores para o Fuji II LC e Freedom; e nos 15 dias finais apresentaram diferença de liberação, com maior valor para o Vitremer, seguido pelo Fuji II LC, Ketac-Fil e Freedom. A comparação dos resultados entre o 1º dia e o 16º dia (após aplicação do gel) mostrou uma maior liberação de flúor no 16º para o Vitremer, Fuji II LC e Freedom e igual para o Ketac-Fil. Embora todos os materiais avaliados tenham ganhado flúor pela aplicação de fluorfosfato acidulado, os dados sugerem que os cimentos de ionômero de vidro modificados por resina são mais eficientes para liberar o flúor do que os outros materiais.The release of fluoride from restorative materials (Vitremer, Ketac-Fil, Fuji II LC and Freedom) was evaluated during two 15-day periods, before and after a topical application of acidulated phosphate fluoride gel (APF). For each material, 6 specimens were made, which were immersed in 2 ml of deionized water. The fluoride concentration dosages in the solutions were read at intervals of 24 hours for 15 days. After this period, the specimens of each material received treatment with APF gel for 4 minutes and the fluoride released was analyzed at 24-hour intervals during the following 15 days. The analysis of variance and the Tukey test (p < 0.05) showed that the total mean fluoride released during the initial 15 days was greater for Vitremer and Ketac-Fil and lower for Fuji II LC and Freedom; and in the final 15 days there was a difference in release readings, with the greatest value for Vitremer, followed by Fuji II LC, Ketac-Fil and Freedom. The comparison of the results between the 1st day and the 16th day (after gel application) showed a greater fluoride release on the 16th day for Vitremer, Fuji II LC and Freedom and was equal for Ketac-Fil. Although all the materials evaluated gained fluoride with the application of APF, the data suggest that the resin-modified ionomers are more efficient in releasing fluoride to the medium than the other materials

Influência da aplicação de flúor sobre a rugosidade superficial do ionômero de vidro Vitremer e adesão microbiana a este material

Os cimentos ionoméricos representam importante opção de material restaurador em Odontologia e sua adesão à estrutura dental, diminuindo a infiltração marginal, somada à liberação de flúor, inibindo o metabolismo de microrganismos acidogênicos e favorecendo a remineralização dental, podem diminuir a ocorrência de cárie secundária. A aplicação tópica de géis acidulados ou neutros contendo flúor tem sido largamente utilizada em Odontologia. No entanto, este procedimento pode afetar a integridade dos materiais restauradores, aumentando sua rugosidade e a retenção de placa bacteriana. Dessa forma, o presente estudo avaliou o período de tempo no qual o cimento ionomérico Vitremer mantém sua capacidade inibitória sobre Streptococcus mutans ATCC 25175 e a adesão dos mesmos sobre a superfície do material, bem como a influência da aplicação tópica de flúor acidulado e neutro sobre esses parâmetros microbiológicos e as características superficiais daquele material. Verificou-se que a atividade antimicrobiana do cimento ionomérico Vitremer se mantém por aproximadamente quatro dias e não é recuperada com o uso de flúor gel acidulado ou neutro. Observou-se, também, que Streptococcus mutans ATCC 25175 adere ao material restaurador testado sendo que a aplicação tópica de flúor não influenciou esta adesão. As características superficiais desses materiais não se alteraram com a aplicação dos géis.Glass ionomer cements are important options in restorative and preventive dentistry due to their adhesion to the tooth surface and to fluoride release, which can decrease the risk of recurrent caries. The topical use of acidulated and neutral fluoride gels has been frequent in dentistry. However, this procedure can adversely affect the surface of restorative materials, increasing their roughness and the retention of dental plaque. Thus, this study evaluated the period in which Vitremer glass ionomer cement maintains its antimicrobial activity over Streptococcus mutans ATCC 25175, as well as the effects of topical application of acidulated and neutral fluoride gels on these microbiological parameters and on the superficial characteristics of the restorative material. It was verified that the antimicrobial activity of Vitremer is very transient, decreasing to an undetectable level after four days, and the topical application of fluoride gel did not restore this activity. It was observed that S. mutans ATCC 25175 adheres to this restorative material, and the topical fluorides did not affect this event. The surface of Vitremer was not altered by the application of fluoride gels

Resin-modified glass ionomer containing calcium glycerophosphate: physico-mechanical properties and enamel demineralization

Sources of calcium and phosphate have been added to dental restorative materials to improve their anticaries effect. Objective: This study evaluated the effect of adding calcium glycerophosphate (CaGP) to resin-modified glass ionomer cement (RMGIC) on the physico-mechanical properties, ion release, and enamel demineralization. Material and Methods: Specimens were fabricated for each experimental group: RMGIC without CaGP (Control), RMGIC with 1, 3 and 9% CaGP. To determine the release of fluoride (F), calcium (Ca) and phosphorus (P), six specimens were immersed in demineralization and remineralization solutions for 15 days. In another experimental trial, the following physico-mechanical properties were evaluated at time intervals of 1 and 7 days after fabrication: compressive strength (n=12), diametral tensile strength (n=12), surface hardness of material (n=6) and the degree of conversion of monomers (n=8). To study enamel demineralization, specimens (n=12) were attached to enamel blocks and submitted to pH-cycling. Subsequently, surface and cross-sectional hardness and the concentration of F, Ca and P in enamel were determined. Results: The addition of CaGP to RMGIC led to higher mean release of F, Ca and P when compared with control (p&lt;0.001). Mechanical properties were within the range of those of the ionomer cements after addition of 1% and 3% CaGP. The degree of conversion did not differ between groups at the 1st and the 7th day (p&gt;0.439). The addition of 3% and 9% CaGP reduced mineral loss and increased F, Ca and P in the enamel when compared with control (p&lt;0.05). Conclusion: The addition of 3% CaGP in RMGIC increased the release of F, P and Ca, reduced enamel demineralization, and maintained the physico-mechanical properties within the parameters for this material

Evaluation of cases of concussion and subluxation in the permanent dentition: a retrospective study

Objectives: This study evaluated the evolution of cases of concussion and subluxation through a retrospective study of 20 years. Material and Methods:Were examined clinical and radiographic records of 1,309 patients who underwent treatment of dentoalveolar trauma in the discipline of Integrated Clinic of the School of Dentistry of Araçatuba, UNESP, of which we selected 137 whose patients had concussion and subluxation injuries, with average age of 23.3 (SD – 10.96). The variables collected were: gender, age, history of previous and actual trauma, treatments performed, the presence of necrotic pulp, and time elapsed until the same trauma. The concussion and subluxation groups were subjected to statistical analyses using the SPSS 16.0 version software (α=0.05), Chi-square, and t-tests. Results: Of the 301 teeth involved, 49 (16.3%) suffered concussion and 252 (83.7%), subluxation, being the upper anterior teeth the most affected (75.1%) for both conditions. Subluxation and concussion traumas were more prevalent in men aged 10 to 20 years, most caused by cycling accidents (36.2%). There was a concomitant presence of crown fracture in 21% of cases of concussion and 34.7% of subluxation. Pulp necrosis was detected in 16.3% (concussion) and 27.1% (subluxation) (p=0.12), and most occurred within 6 months after the trauma (p=0.29). The pulp necrosis shows a positive correlation with motorcycle accidents (p=0.01), direct impact (p≤0.0001), crown fracture with pulp exposure (p≤0.0001), darkening of the crown (p=0.004) and spontaneous pain (p≤0.0001); and negative correlation with indirect impact (p≤0.0001). Conclusions: Although concussion and subluxation traumas are considered of minor degrees, they must be monitored, since the possibility of pulp necrosis exists, and its early treatment favors a good prognosis

GESTÃO DE ÁREAS PROTEGIDAS E AVALIAÇÃO DA EDUCAÇÃO AMBIENTAL NO ECOTURISMO: ESTUDO DE CASO COM O PROJETO TRILHA SUBAQUÁTICA – EDUCAÇÃO AMBIENTAL NOS ECOSSISTEMAS MARINHOS – NO PARQUE ESTADUAL DA ILHA ANCHIETA, UBATUBA, SÃO PAULO, BRASIL

The protected areas management faces a varied series of problems that oscillates since the land regularization up to the inefficiency of its programs of public use. The Environmental Education (EE) is a predictable and desirable legal action which is developed in all the Conservation Units (CU), not only in the Brazillian territory but also around the planet. The Evaluation of the Environmental Education in Brazil (EEEB) in the sea does not exist, mainly associated with the Ecotourism in CU’s. The actual paper presents a qualitative Case Study (CS) of the EEEB in a CU with a weakening zone: Anchieta Island State Park, in the State of São Paulo, Brazil. The CS deals with Submarine Trail Project – Environmental Education in the Marine Ecosystems (Sub Trail) of the University of São Paulo. The Sub Trail develops nowadays four types of Marine and Coastal Environmental Education (MCEE). The concepts about the environmental importance of the sea and its impacts have been analysed, such as what the ecotourists have learned in the activities of SubTrail in January 2008. The information has been obtained through interviews with semi structured route. 106 participants of the Sub Trail had been interviewed: 50.9% men and 49.1% women from different ages and school degree, so 18 project trainees and 88 visitors on the island. The number of activities performed by the interviewed people just in the Sub Trail reached to 182. The analyses of the interviews have showed that the able trainees and the ecotourists have properly learned the principal concepts of the activities. The Sub Trail have been adequately qualifying, in terms of basic concepts, its trainees through their sensibilization and the transference of fundamental concepts to the marine ecotourists to the PEIA. Its activities can be improved, having in mind to overcome the conceptual and sensibilization transference phase to look for the citizen emancipation, accomplishing the non targeted part of its conceptual quality indicators derived from the National Program of Environmental Education. The Sub Trail where it is and how it is done, qualifies itself already as a successful experience in the context of the Marine Environmental Education in Brazil. Key words: Evaluation. Environmental Education. Conservation Units. Trail. Ecotourism. Marine Ecosystems.A gestão de áreas protegidas enfrenta uma variada gama de problemas que oscilam desde a regularização fundiária de terras até a ineficácia de seus programas de uso público. A Educação Ambiental (EA) é uma ação legalmente prevista e desejada que seja desenvolvida em todas as unidades de conservação (UC) não só no território brasileiro como em todo o planeta. A Avaliação da Educação Ambiental no Brasil (AEAB no meio marinho inexiste, principalmente associadas ao ecoturismo em UC´s. O presente trabalho apresenta um Estudo de Caso (EC) qualitativo de AEAB numa UC com zona de amortecimento marinho: Parque Estadual da Ilha Anchieta, estado de São Paulo, Brasil. O EC trata do Projeto Trilha Subaquática – Educação Ambiental nos Ecossistemas Marinhos (TrilhaSub) da Universidade de São Paulo. O TrilhaSub desenvolve atualmente quatro modelos de Educação Ambiental Marinha e Costeira (EAMC). Foram analisados os conceitos sobre a importância ambiental do mar, seus impactos e o que os ecoturistas aprenderam nas atividades do TrilhaSub em janeiro de 2008. As informações foram obtidas através de entrevistas com roteiro semi-estruturado. Foram entrevistados 106 participantes do TrilhaSub: 50,9% de homens e 49,1% de mulheres de diversas faixas etárias e escolaridade, sendo 18 monitores do Projeto e 88 visitantes da Ilha. Chegou a 182 o número de atividades realizadas pelos entrevistados apenas no TrilhaSub. A análise das entrevistas mostrou que os monitores capacitados e os ecoturistas apreenderam adequadamente os conceitos principais das atividades. O TrilhaSub vem capacitando adequadamente, em termos conceituais básicos, seus monitores através de sua sensibilização e da transferência de conceitos fundamentais aos visitantes ecoturistas marinhos ao PEIA. Suas atividades poderão ser melhoradas, visando superar a fase de transferência conceitual e sensibilização para a busca da emancipação do cidadão, cumprindo a parte não ainda atingida dos seus próprios indicadores de qualidade conceitual derivados do Programa Nacional de Educação Ambiental. O TrilhaSub no estágio em que se encontra já o qualifica como uma experiência de sucesso no contexto da Educação Ambiental Marinha no Brasil Palavras-chave: Avaliação. Educação Ambiental. Unidades de Conservação. Trilha. Ecoturismo. Ecossistemas Marinhos. Abstract The protected areas management faces a varied series of problems that oscillates since the land regularization up to the inefficiency of its programs of public use. The Environmental Education (EE) is a predictable and desirable legal action which is developed in all the Conservation Units (CU), not only in the Brazillian territory but also around the planet. The Evaluation of the Environmental Education in Brazil (EEEB) in the sea does not exist, mainly associated with the Ecotourism in CU’s. The actual paper presents a qualitative Case Study (CS) of the EEEB in a CU with a weakening zone: Anchieta Island State Park, in the State of São Paulo, Brazil. The CS deals with Submarine Trail Project – Environmental Education in the Marine Ecosystems (Sub Trail) of the University of São Paulo. The Sub Trail develops nowadays four types of Marine and Coastal Environmental Education (MCEE). The concepts about the environmental importance of the sea and its impacts have been analysed, such as what the ecotourists have learned in the activities of SubTrail in January 2008. The information has been obtained through interviews with semi structured route. 106 participants of the Sub Trail had been interviewed: 50.9% men and 49.1% women from different ages and school degree, so 18 project trainees and 88 visitors on the island. The number of activities performed by the interviewed people just in the Sub Trail reached to 182. The analyses of the interviews have showed that the able trainees and the ecotourists have properly learned the principal concepts of the activities. The Sub Trail have been adequately qualifying, in terms of basic concepts, its trainees through their sensibilization and the transference of fundamental concepts to the marine ecotourists to the PEIA. Its activities can be improved, having in mind to overcome the conceptual and sensibilization transference phase to look for the citizen emancipation, accomplishing the non targeted part of its conceptual quality indicators derived from the National Program of Environmental Education. The Sub Trail where it is and how it is done, qualifies itself already as a successful experience in the context of the Marine Environmental Education in Brazil. Key words: Evaluation. Environmental Education. Conservation Units. Trail. Ecotourism. Marine Ecosystems. OLAM - Ciência & Tecnologia, Rio Claro, SP, Brasil – eISSN: 1982-7784 está licenciada sob Licença Creative Commons. Rio Claro / SP, Brasil Ano VIII Vol. 8 No.2, Janeiro - Junho / 2008 – RESUMO

Cor ASTM: um método simples e rápido para determinar a qualidade do biodiesel produzido a partir de óleos residuais de fritura

In this study, 23 biodiesel samples were produced, 20 from used cooking oil and the remaining 3 from refined soybean oil. The following properties were determined in all of the samples (oil and its respective biodiesel): density; viscosity; total acid number and ASTM color. The results indicated high correlation (R > 0.6) between ASTM color of used cooking oil and total acid number of its resultant biodiesel. This high correlation allows prediction of the quality of the biodiesel produced using a simple and fast procedure such as ASTM color

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| &lt; 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe