Grado de microfiltración en ionómero de vidrio y resina compuesta nanoparticulada en lesiones cervicales no cariosas / Degree of microleakage in glass ionomer and nanoparticulate composite resin in non-carious cervical lesions

Introducción: El grado de microfiltración en el ionómero de vidrio y la resina compuesta nanoparticulada en lesiones cervicales no cariosas es de gran importancia para elegir el material restaurador más adecuado para cada caso clínico. Objetivo: Describir el grado de microfiltración en ionómero de vidrio y resina compuesta nanoparticulada en lesiones cervicales no cariosas. Métodos: Se realizó una revisión bibliográfica, correspondiente al nivel exploratorio, en busca de responder cinco preguntas científicas sobre el tema. Se identificaron 62 artículos de las bases de datos de Google Académico o Scopus entre 2015 y 2022. Resultados: Los estudios consultados sugieren que la resina compuesta nanoparticulada es una opción de restauración efectiva y estética en odontología, especialmente en casos de cavidades de alta carga mecánica y estética dental. Los estudios de casos que se revisan demuestran que el grado de microfiltración en las lesiones cervicales no cariosas puede ser significativamente mayor en las restauraciones con ionómero de vidrio en comparación con las resinas compuestas nanoparticuladas. Conclusiones: Se concluye que el elemento fundamental en el tratamiento es realizar un correcto diagnóstico, determinando las necesidades para mejorar la salud dental y realizar una correcta planificación, por lo que es necesario conocer los diferentes tipos de tratamientos con la finalidad de seleccionar el más adecuado, que cumpla con las características biológicas, mecánicas y estéticas, ya que uno de los objetivos fundamentales de cualquier tratamiento es devolver la función y la estética de modo satisfactorio y con la mayor durabilidad posible.

Introduction: The degree of microleakage in glass ionomer and nanoparticulated composite resin in non-carious cervical lesions is of great importance for choosing the most suitable restorative material for each clinical case. Objective: To describe the degree of microleakage in glass ionomer and nanoparticulated composite resin in non-carious cervical lesions. Methods: A literature review, corresponding to the exploratory level, was carried out to answer five scientific questions on the subject. Sixty-two articles were identified from Academic Google or Scopus databases between 2015 and 2022. Results: The studies consulted suggest that nanoparticulated composite resin is an effective and esthetic restorative option in dentistry, especially in cases of cavities with high mechanical load and dental esthetics. The case studies reviewed demonstrate that the degree of microleakage in non-carious cervical lesions can be significantly higher in glass ionomer restorations compared to nanoparticulated composite resins. Conclusions: It is concluded that the fundamental element in treatment is to carry out a correct diagnosis, determining the needs to improve dental health and to carry out correct planning, so it is necessary to know the different types of treatments with the aim of selecting the most suitable one, which complies with the biological, mechanical and esthetic characteristics, since one of the fundamental objectives of any treatment is to restore function and esthetics in a satisfactory way and with the greatest possible durability.

Sellado marginal aplicando hipoclorito de sodio versus ácido fosfórico como acondicionador dental / Marginal sealing applying sodium hypochlorite versus phosphoric acid as dental conditioner

RESUMEN Introducción: La microfiltración es uno de los problemas principales de todas las obturaciones a base de resina. Muchos estudios buscan optimizar un buen sellado marginal utilizando diversos acondicionadores, como el hipoclorito de sodio, que permite que el adhesivo penetre bien, al generar desproteinización, y el ácido fosfórico que permite remover el barro dentinario, y así de esta manera formar una capa híbrida al colocar el adhesivo. Objetivo: Evaluar el grado de sellado marginal de la resina Bulk Fill aplicando gel de hipoclorito de sodio 10 por ciento comparado con el gel de ácido fosfórico al 37 por ciento en el acondicionamiento dental in vitro. Métodos: El universo fue de 72 dientes con cavidades clase I; se separaron en 4 grupos por muestra de 18 dientes cada uno; después de obturar se realizó el termociclaje a 500 ciclos entre 5 °C a 55 °C; luego se sumergieron en azul de metileno 2 por ciento, durante 12 h y 24 h a temperatura de 37 °C. Finalmente se evaluó el sellado marginal en el estereomicroscopio, según el ISO / TS 11405: 2015, con los criterios siguientes: grado 0 (sin microfiltración), grado 1 (microfiltración hasta esmalte), grado 2 (microfiltración hasta dentina) y grado 3 (microfiltración hasta piso pulpar). Resultados: El acondicionamiento con ácido fosfórico 37 por ciento a las 12 h presentó grado 0 (55,6 por ciento) y grado 1 (33,3 por ciento), y a las 24 h, grado 1 (55,6 por ciento). Con respecto al hipoclorito de sodio 10 por ciento a las 12 h, grado 0 (44.4 por ciento) y a las 24 h predominó grado 1 (55,6 por ciento). Para la contrastación de hipótesis en muestras relacionadas se obtuvo en ácido fosfórico 37 por ciento e hipoclorito de sodio al 10 por ciento a las 12 h y 24 h un p= 0,052 y p= 0,584, respectivamente. Para comparaciones entre muestras independientes a las 12 h y 24 h se obtuvo p= 0,462 y p= 0,406, respectivamente. Conclusiones: El gel de hipoclorito de sodio al 10 por ciento presenta similar eficacia en el sellado marginal respecto al gel de ácido fosfórico al 37 por ciento, al utilizarlo como acondicionador dental(AU)

ABSTRACT Introduction: Microfiltration is one of the main problems of all resin sealings. Many studies aim to optimize marginal sealing using a variety of conditioners, such as sodium hypochlorite, which allows good penetration of the adhesive by generating deproteinization, and phosphoric acid, which allows removal of the dental smear layer, thus creating a hybrid layer when the adhesive is placed. Objective: Evaluate the marginal sealing degree of Bulk Fill resin applying 10 percent sodium hypochlorite gel versus 37 percent phosphoric acid gel in in vitro dental conditioning. Methods: The study universe was 72 teeth with class I cavities, divided into four groups of 18 teeth. Upon sealing, thermal cycling was performed at 500 cycles from 5 ºC to 55 ºC. Next the teeth were submerged in 2 percent methylene blue for 12 h and 24 h at a temperature of 37 ºC. Finally marginal sealing was evaluated in the stereo microscope according to ISO / TS 11405: 2015, using the following scale: grade 0 (no microfiltration), grade 1 (microfiltration as far as the enamel), grade 2 (microfiltration as far as the dentin), and grade 3 (microfiltration as far as the pulp floor). Results: Conditioning with 37 percent phosphoric acid was grade 0 (55.6 percent) and grade 1 (33.3 percent) at 12 h, and grade 1 (55.6 percent) at 24 h, whereas conditioning with 10 percent sodium hypochlorite was grade 0 (44.4%) at 12 h, and predominantly grade 1 (55.6 percent) at 24 h. Hypothesis contrast in related samples yielded 37 percent phosphoric acid and 10 percent sodium hypochlorite at 12 h and 24 h, p= 0.052 and p= 0.584, respectively. Comparison between independent samples at 12 h and 24 h yielded p= 0.462 and p= 0.406, respectively. Conclusions: The 10 percent sodium hypochlorite gel has similar marginal sealing effectiveness as the 37 percent phosphoric acid gel when used as dental conditioners(AU)

Combinação de processos com membranas para remoção de sulfato da água do mar para injeção em reservatórios de petróleo / Combination of membrane processes for desulfation of seawater used for injection in oilfields

RESUMO Água do mar é comumente utilizada como fluido de injeção em plataformas offshore na recuperação secundária do petróleo. Porém, a presença de sulfato causa diversos inconvenientes, como a formação de precipitados, que podem se depositar em diversas partes da plataforma de produção. Atualmente, a dessulfatação é realizada em unidades removedoras de sulfato (URS) por processo de nanofiltração (NF), cujas amostras precisam ser pré-tratadas, usualmente em filtros cartuchos. Os sólidos suspensos e os microrganismos que não foram retidos pelo sistema de filtração podem depositar sobre a superfície das membranas de NF, diminuindo a produtividade do sistema e reduzindo o tempo de vida das membranas. O processo de microfiltração (MF) pode ser utilizado como pré-tratamento alternativo e possibilitaria a remoção desses elementos. Neste estudo, foi desenvolvido um processo combinado de MF e NF para a dessulfatação da água do mar, visando a sua injeção em reservatórios de petróleo. Módulos de permeação contendo membranas de poli(imida) no formato de fibras ocas foram utilizados na construção de um sistema piloto de MF integrado a um sistema piloto de NF similar aos já atualmente utilizados nas plataformas. O desempenho dos sistemas foi avaliado por meio do acompanhamento da permeabilidade de ambos durante a filtração da água do mar. Parâmetros como grau de recuperação de água, frequência e eficiência de procedimentos de retrolavagem e limpeza química também foram estudados. Os resultados demonstraram que o pré-tratamento da água do mar por MF é uma alternativa eficaz para a dessulfatação por NF.

ABSTRACT Seawater is commonly used in offshore platforms as an injection fluid in secondary oil recovery. However, the sulfate found in seawater has been the cause of many inconveniences, such as the formation of precipitates, which can settle in various parts of the production platform. Nowadays, nanofiltration (NF) is used in sulfate removal units for seawater desulfation, where cartridge filters are commonly used for seawater pretreatment. Suspended solids and microorganisms that have not been retained by the filtration system may deposit on the surface of NF membranes, decreasing system productivity and reducing membrane life. The microfiltration (MF) process can be used as an alternative pretreatment and would allow the removal of these elements. In this study, a combined process of MF and NF for seawater desulfation was developed for injection into oil reservoirs. Permeation modules containing hollow fiber shaped poly (imide) membranes were used in the construction of an MF pilot system, integrated with an NF pilot system similar to those already used on platforms. The performance of the systems was evaluated by monitoring the permeability of both during seawater filtration. Parameters such as degree of water recovery, frequency, and efficiency of backwash procedures and chemical cleaning were also studied. The results showed that MF seawater pretreatment is an effective alternative for NF desulfation.

Fibra óptica como un material alternativo en la obturación endodóncica: un estudio piloto / Optical fiber as an alternative material in endodontics: a pilot study

La gutapercha es químicamente un polímero a base de isopreno, impermeable, no poroso y radiopaco entre otras características, empleado desde el siglo XIX; sin embargo manifiesta algunos inconvenientes propios del material, lo cual ha dado lugar al nacimiento de otros materiales para mejorar sus propiedades. Recientemente se ha desarrollado y caracterizado un material novedoso a base de fibra óptica recubierta por nano partículas de plata (FONP), propuesto como un material alternativo para la obturación de conductos radiculares. En el presente estudio se seleccionaron 24 dientes para conformar cuatro grupos experimentales comparativos entre la obturación con fibra óptica y con gutapercha, ambos con el sellador AH Plus. Las raíces fueron obturadas en grupos de diez y almacenadas en solución salina a 37 oC. La filtración apical se midió desde el extremo apical de la interfaz del material hasta la extensión más coronal del tinte observado microscópicamente. Se empleó la herramienta de LAS EZ V3.0 (Leica Microsystems, Switzerland), los datos se tabularon y se analizaron. Resultados: Las mediciones de microfiltración a nivel apical e intraconductos manifestaron diferencias en favor de la gutapercha, donde los grupos experimentales manifestaron una filtración promedio correspondiente a 0.872 mm en el grupo de Gutapercha/AH-PLUS y de 2.390 mm con técnica lateral utilizando FONP/AH-PLUS, aun así se evidenció que las propiedades de sellado de la fibra óptica con nanopartículas fueron suficientes para considerarlo como un material de obturación de conductos radiculares dentales como posible sustituto de la gutapercha (AU)

Gutta-percha is chemically an Isoprene-based polymer, impervious, non-porous and radiopaque, among other characteristics, used since the 19th century, it manifests some disadvantages inherent to the material, which has led to the birth of new materials with improved properties. Recently, a novel material based on optical fiber covered by silver nanoparticles (FONP) has been developed, characterized and proposed as an alternative material for root canal obturation. In the present study, 24 teeth were selected and divided into four comparative experimental groups for obturation with fiber optics and gutta-percha, both with the AH Plus sealer. The roots were sealed in groups of ten and stored in saline at 37 oC. Apical filtration test was performed from the apical end of the material interface to the most coronal extension of the dye observed microscopically. The LAS EZ V3.0 tool was used to make the measurements and the data was tabulated and analyzed. Results: Measurements of microfiltration at the apical and intracanal level showed differences in favor of gutta-percha, where the experimental groups showed an average filtration of 0.872 mm in the Gutapercha/AH-PLUS group and 2.390 mm using FONP/AH-PLUS, even so, it was evidenced that the sealing properties of the optical fiber with nanoparticles are sufficient to consider this material as a proper filling material for dental root canals as a substitute for gutta-percha (AU)

Avaliação de parâmetros operacionais de um sistema de membranas para tratamento de efluentes oleosos / Evaluation of a membrane system's operational parameters for oily effluent treatment

RESUMO O objetivo deste trabalho foi discutir os principais parâmetros de controle de um sistema de membranas de microfiltração para remoção de óleo de efluentes com base em ensaios experimentais. Os ensaios utilizaram efluentes sintéticos com diâmetros de gotas de óleo entre 4 e 8 µm. As membranas usadas foram do tipo fibra oca com módulo submerso. Foram testados os seguintes parâmetros: concentrações de óleos e graxas na alimentação das membranas (O&Gam) entre 100 e 260 mg.L-1; taxas de recuperação de água (Rec) de 0,75 e 0,90; e pressões através das membranas (Δp) de -0,20 e -0,30 bar. Os resultados mostraram que as membranas produzem um permeado com uma qualidade boa a ponto de possibilitar o seu reúso em atividades industriais diversas. Foi também observado que a elevação da O&Gam e da Rec acentuam o declínio de fluxo com o tempo e que a elevação da Δp aumenta o valor do fluxo no tempo de seis horas.

ABSTRACT The aim of this paper is to discuss the main control parameters of a microfiltration membranes system for oil removal from effluent on experimental bases. The experiments were conducted by using synthetic effluent with oil droplets diameter ranging from 4 to 8 microns. The membranes used were hollow fiber-type which were assembled in a submerged module. The following parameters were tested: Oil and grease concentration in the feed stream (O&Gf ) of 100 and 200 mg.L-1, Water recovery rates (WRR) of 0.75 and 0.90, and Transmembrane pressure (TMP) of -0.20 and -0.30 bar. The results showed that the membranes produced a permeate with a good quality to the point of enabling their reuse in several industrial activities. It was also observed that the elevation of O&Gf and WRR increase the flux decline over time and that the increase of TMP increases the flow value in time of 6 hours.

In vitro comparative study of apical microfiltration in retrograde fillings between dental cements: MTA Repair Hp and Biodentine / Estudio comparativo"in vitro" de lamicro filtración apical en obturaciones retrógradasentre cementos dentales: MTA Repair Hp y Biodentine

Abstract Objective: To compare "in vitro" the degree of bacterial microfiltration in the apical third of the root canal, when performing the retrograde filling technique using two endodontic cements: MTA Repair Hp (Angellus) and Biodentine (Septodont). Materials and methods: Twenty-two uniradicular teeth were used (upper central and lateral incisors), whose ducts were instrumented up to the working length with the Limas K File hand instruments (Dentsply / Maillefer, Ballaigues, Switzerland). The teeth were randomly divided into 4 groups A, B, C and D, group A and B of 10 teeth each. The root canals of group A were obturated using retrograde technique with MTA Repair Hp, and those of Group B with Biodentine, Group C root canals positive control, Group D root canals negative control. The samples were screened and photographed, and the images were analyzed in the three thirds root using the program Motic Images 5.0. Results: Group A (MTA Repair Hp) showed a greater penetration of Chinese ink in the last 3 millimeters of the apical third, as well as in the middle third in relation to Group B (Biodentine), and although this difference was not statistically significant one observed a tendency to smaller microfiltrations with Biodentine. Conclusion: The technique of retrograde obturation with Biodentine presents a greater tendency to provide a more hermetic peripheral seal of the apical third, as compared to the retrograde obturation technique with MTA Repair Hp.

Resumen Objetivo: Comparar "in vitro" el grado de microfiltración bacteriana en el tercio apical del conducto radicular, al realizar la técnica de obturación retrógrada mediante el uso de dos cementos endodónticos: el MTA Repair Hp (Angellus) y el Biodentine (Septodont). Materiales y Métodos: Se utilizaron 22 dientes uniradiculares extraídos (incisivos centrales y laterales superiores) cuyos conductos fueron instrumentados hasta la longitud de trabajo con los instrumentos manuales Limas K File (Dentsply/Maillefer, Ballaigues, Suiza). Los dientes se dividieron al azar en 4 grupos A, B, C y D, el grupo A y B de 10 piezas dentales cada uno. Los conductos radiculares del grupo A fueron obturados mediante técnica retrógrada con MTA Repair Hp, y los del Grupo B con Biodentine, Grupo C conducto control positivo, Grupo D conducto control negativo. Las muestras fueron transparentadas y fotografiadas, y las imágenes se analizaron en los tres tercios radiculares mediante el programa Motic Images 5.0. Resultados: El grupo A (MTA Repair Hp) mostró una penetración mayor de la tinta china en los 3 últimos milímetros del tercio apical, así como en tercio medio respecto al Grupo B (Biodnetine), y aunque esta diferenciano fue estadísticamente significativa si se observa una tendencia a menores microfiltraciones con el Biodentine. Conclusión: La técnica de obturación retrógrada con Biodentine presenta una mayor tendencia a brindar un sellado periférico más hermético del tercio apical, en comparación con la técnica de obturación retrógrada con MTA Repair Hp.

Pilot technological process evaluation of Compound Banlangen Liyan Granules / 中草药

Objective: To evaluate the pilot technological process of Compound Banlangen Liyan Granules (CBLG). Methods: According to the indexes of six effective ingredients loss amount, accumulated loss rate, and HPLC characteristic spectrum similarity, the process quality of four key processes was evaluated and compared, such as microfiltration of ceramic membrane, vacuum concentration of extract, vacuum drying of concrete, and atmospheric drying of granules. Results: It was found that the total loss rates of glycyrrhizic acid, harpagoside, (R,S)-epigoitrin, liquiritin in two batches were 50.06%—66.99%, and angoroside C, adenosine were 35.49%—41.90%. The total content of the six effective ingredients of each material within the same batch of the two pilot batches from high to low were as follows: extract solution before membrane filtration > extract solution after membrane filtration > concentrate extract solution > dried concrete powder > granules of finished product. The comparison among four key processes loss rates was as follows: vacuum drying of concrete > ceramic membrane microfiltration > vacuum concentration of extract, atmospheric drying of granules. Loss amount of concrete vacuum drying process of the two pilot batches were 0.545 9 and 0.737 5 mg/g, and the process was the major loss process. The total loss rates of the two pilot batches were 48.15%, 50.85%, respectively. The HPLC characteristic spectrum similarity of each material within the same batch of the two pilot batches decreased from 0.998 to 0.818 with increasing process. The HPLC characteristic between the two batches of finished products was good (the similarity was 0.999). Conclusion: The consistency of the finished product quality between two batches was good. The study provided a basis for pilot production process control of CBLG. In the modernization and standardization study of traditional Chinese medicine preparation process, mild process of low temperature and short time heating should be applied as far as possible. It can reduce the effective components loss of original extract (decoction of herbal medicine) in the preparation process and maintain the quality and efficacy consistency of traditional Chinese medicine preparation and original extract (decoction of herbal medicine).

ANÁLISIS DE UN JUGO DE MORA (Rubus adenotrichos) ENDULZADO CON ESTEVIA (Stevia rebaudina Bertoni), UNA APROXIMACIÓN METABOLÓMICA

La investigación tuvo como propósito analizar, a través de una aproximación de estudio metabolómico, la composición integral de un jugo microfiltrado a base de mora (Rubus adenotrichos), endulzado con hojas deshidratadas de estevia (Stevia rebaudiana Bertoni) y su comparación con análogos obtenidos por tratamiento térmico convencional, endulzados con sacarosa. Para el registro de la información espectral, se optó por un enfoque no dirigido, en el que se midieron, simultáneamente, tantos metabolitos, como fue posible, en los cuatro tipos de muestras elaboradas (jugo microfiltrado no pasteurizado y pasteurizado, endulzado con estevia y sacarosa). Fue empleado un sistema de Cromatografia Líquida de Ultra Alta Resolución (UPLC), equipado con un detector de red de fotodiodos (PDA) acoplado a un electrospray de ionización y dispuesto con Q-TOF al espectrómetro de masas (ESI-Q-TOF/MS). Con base en los archivos formato SPL, aportados por el UPLC y, una vez convertidos a formato NetCDF, se efectuó el análisis respectivo, en el software MZmine, el cual, detectó cada uno de los iones presentes, discriminando la presencia o no de los mismos, en las diferentes muestras, identificándolos según su masa (molecular) y el tiempo de retención donde fueron registrados en el espectro, por el espectrómetro de masas. De acuerdo con las deducciones generadas, el análisis estadístico aplicado, confirmó la variación de la composición del jugo endulzado, tanto con estevia como con sacarosa, al ser sometidos a tratamiento térmico, al corroborar diferencias estadísticamente significativas, lo que permite afirmar que el tratamiento, para las formulaciones estudiadas, genera una variación de los iones presentes.

The purpose of the research was to analyze, through a metabolomic study, the overall composition of a microfiltration blackberry juice (Rubus adenotrichous) sweetened with dried leaves of stevia (Stevia rebaudiana Bertoni) and its comparison with analogues obtained by conventional heat treatment, sweetened with sucrose. The spectral information was obtained by an undirected approach. all possible metabolites produced in the four samples (unpasteurized and pasteurized microfiltered juice, sweetened with stevia and sucrose) were measured simultaneously. Analyses were conducted in series using a Waters Acquity Ultra Performance Liquid Chromatography system (UPLC) equipped with a photodiode array detector (PDA) and coupled with Electrospray Ionization and Quadrupole Time-Of-Flight Mass Spectrometry (ESI-Q-TOF/MS. SPL format files, provided by the UPLC, in the analysis of the samples were converted to NetCDF format, the respective analyzes were performed by the MZmine software. all ions were detected, discriminating presence or not in the different samples. The mass (molecular) and the retention time were recorded by the mass spectrometer. The results of the statistical analysis applied confirmed the variation in composition microfiltration blackberry juice sweetened with sucrose and stevia when subjected to heat treatment step, corroborating statistically significant differences between them, which allows to affirm that the treatment for the formulations studied generates a variation of the ions present.

Adsorption characteristics of proteins on membrane surface and effect of protein solution environment on permeation behavior of berberine / 中国中药杂志

In order to explore the adsorption characteristics of proteins on the membrane surface and the effect of protein solution environment on the permeation behavior of berberine, berberine and proteins were used as the research object to prepare simulated solution. Low field NMR, static adsorption experiment and membrane separation experiment were used to study the interaction between the proteins and ceramic membrane or between the proteins and berberine. The static adsorption capacity of proteins, membrane relative flux, rejection rate of proteins, transmittance rate of berberine and the adsorption rate of proteins and berberine were used as the evaluation index. Meanwhile, the membrane resistance distribution, the particle size distribution and the scanning electron microscope (SEM) were determined to investigate the adsorption characteristics of proteins on ceramic membrane and the effect on membrane separation process of berberine. The results showed that the ceramic membrane could adsorb the proteins and the adsorption model was consistent with Langmuir adsorption model. In simulating the membrane separation process, proteins were the main factor to cause membrane fouling. However, when the concentration of proteins was 1 g•L⁻¹, the proteins had no significant effect on membrane separation process of berberine.

Evaluation of microleakage degree in composite resin restorations by comparing two adhesives systems after different aging periods / Evaluación del grado de microfiltración en restauraciones de resina compuesta, comparando dos sistemas adhesivos tras diferentes períodos de envejecimiento

ABSTRACT Introduction: the clinical success of adhesive systems is based on the use of a responsible for creating microporosity in the dental structure acid and arises assess in vitro the degree of microfiltration in direct restorations with cavities class V where two adhesive systems differently used composition and at different periods of time. Methods: in the cervical third of 60 third molars extracted by therapeutic indication performed by diamond instruments, two cavities one on the vestibular side and one on the palatal or lingual side; It separated into two groups of 30 in the first acid conditioning was performed and then applied -Voco Admire bond while the second group Futurabond-Voco applied; both groups were restored with resin composite Admira-Voco, each group was divided into two subgroups of 15 subgroups A were subjected to thermal cycling for 10800 cycles and 5400 cycles B subgroups. It concluded these periods proceeded to staining with methylene blue and then a cut is made lengthwise to assess the income of the dye in the interface formed; this pigmentation was evaluated and measured under stereomicroscope. Results: the obtained data were statistically analyzed by Tukey′s test, which showed the existence of differences between the groups evaluated, so evident at the level of cervical margin with a p > 0.05 Conclusions: it is evident that the artificial aging increased microfiltration resin composite restorations regardless of the type of adhesive system used.

RESUMEN Introducción: el éxito clínico de los sistemas adhesivos está basado en el empleo de un ácido responsable de crear microporosidades en la estructura dental, así se plantea evaluar in vitro el grado de microfiltración existente en restauraciones directas con cavidades clase V donde se emplean dos sistemas adhesivos de diferente composición y en diferentes períodos de tiempo. Métodos: en el tercio cervical de 60 terceros molares extraídos por indicación terapéutica se realizaron, mediante instrumentos diamantados, dos cavidades: una en la cara vestibular y otra en la cara palatina o lingual, y fueron separados en dos grupos; en el primero se efectuó acondicionamiento ácido y luego se aplicó Admira bond- Voco, mientras que en el segundo se aplicó Futurabond NR-Voco. Ambos grupos fueron restaurados con resina compuesta Admira-Voco, cada grupo fue dividido en dos subgrupos de 15, los subgrupos A fueron sometidos a termociclado por 10800 ciclos y los subgrupos B por 5400 ciclos. Concluidos estos períodos, se procedió a su tinción con azul de metileno y luego se efectuó un corte en sentido longitudinal para evaluar el ingreso del colorante en la interface formada; esta pigmentación fue evaluada y medida bajo microscopio estereoscópico. Resultados: los datos obtenidos fueron analizados estadísticamente mediante el test de Tukey, que demostró la existencia de diferencias entre los grupos evaluados, de forma más evidente a nivel del margen cervical, con un p > 0,05. Conclusiones: se evidencia que el envejecimiento artificial aumentó la microfiltración de las restauraciones de resina compuesta independientemente del tipo de sistema adhesivo empleado.

Influencia de la calidad de restauración coronal en el pronóstico de dientes tratados endodónticamente / Influence of the quality of coronal restoration in the prognosis of endodontically treated teeth

Introducción: la restauración de dientes tratados endodónticamente es compleja y controversial y su pronóstico está directamente relacionado con la calidad del tratamiento endodóntico y la restauración definitiva, lo que debe asegurar un correcto sellado marginal para evitar la filtración coronaria y el posterior fracaso endodóntico. Se ha demostrado que la aplicación de un inadecuado protocolo en el tratamiento del conducto posendodoncia podría causar fracasos por el arrastre y filtración de microorganismos que se encuentran en la cavidad oral y sus productos derivados hacia la porción apical de la raíz. Muchos factores a lo largo de las fases del tratamiento endorrestaurador influyen directamente en su pronóstico: calidad del sellado apical, cantidad de gutapercha remanente, desobturación temprana o tardía, capacidad de sellado de la restauración temporal o definitiva, desinfección del conducto, entre otras. Objetivo: actualizar a profesionales acerca de los parámetros clínicos a tener en cuenta en la rehabilitación de dientes tratados endodónticamente, que implica realizar todos los procedimientos bajo un estricto protocolo y una adecuada cadena aséptica para evitar contaminación bacteriana. Métodos: la búsqueda bibliográfica se llevó a cabo utilizando los siguientes términos: restauración coronal, microfiltración, desobturación radicular, calidad y estado endondóntico; se seleccionaron los artículos que evaluaron el efecto de la calidad de la obturación radicular, la restauración coronal o ambas, en el éxito de una endodoncia. Cincuenta y tres artículos fueron identificados y revisados por dos investigadores. Los datos fueron obtenidos de bases de datos como: Hinari, Sciencedirect, Wiley interscience, SciELO y fuentes indexadas nacionales e internacionales con criterios predeterminados. Resultados: de acuerdo con los conceptos de control de infección, todos los instrumentos y el material colocado dentro del conducto radicular deben ser estériles. La prevención de la microfiltración es un aspecto importante en el éxito del diente tratado endodónticamente, que debe ser rehabilitado en un período corto entre la endodoncia y la restauración definitiva, para reducir de forma considerable la contaminación. Conclusiones: sobre la base de la evidencia disponible se puede afirmar que, independiente de la técnica o material de obturación endodóntica o tipo de restauración, es indispensable mantener la cadena aséptica a lo largo de todo el tratamiento, lo que sumado a una adecuada restauración definitiva favorece la conservación del sellado a nivel coronal y apical que minimice al máximo el riesgo de contaminación bacteriana(AU)

Introduction: the restoration of endodontically treated teeth is complex and controversial, and its prognosis is directly related to the quality of endodontic treatment and the final restoration, which should ensure a proper marginal seal to prevent coronary filtration and avoid subsequent endodontic failure. It has been shown that to handle badly a post-endodontic canal could cause failures for skiddingand microorganisms filtration which are found in the oral cavity and derived products to the apical portion of the root. Many factors during the endo-restorer treatment phase directly influence in its prognosis: apical sealant quality, residual amount of gutta-percha, early or late desobturation, sealing ability of the temporary or permanent restoration, disinfection canal among other. Objective: the purpose is to update professionals about clinical parameters to take into account in the rehabilitation of endodontically treated teeth, for this it is necessary to follow all the procedures under strict protocol and proper aseptic chain to prevent bacterial contamination. Methods: the literature search was conducted using the following terms coronal restoration, microfiltration, desobturation root, quality and endodontic status, articles that evaluated the effect of the quality of the root filling and coronal restoration or both in the success of a root canal were selected. Fifty-three articles were identified and reviewed by two investigators. Data were obtained from databases such as: Hinari, Science Direct, Wiley interscience, and indexed sources national and indexed sources national and international to predetermined criteria. Results: according to the concepts of infection control, all instruments and equipment placed inside the root canal must be sterile. Prevention of microfiltration is an important success endodontically treated tooth appearance, which must be rehabilitated in a short period of time between endodontics and final restoration to significantly reduce contamination. Conclusions: based on the available evidence, the results say that regardless of the technical or endodontic filling material or type of temporary or permanent restoration, is essential to maintain the aseptic chain along the whole treatment which added to an adequate final restoration promote the conservation sealed coronal y apical level to reduce the risk of bacterial(AU)

Effects of Microfiltration Membrane Adsorption on Detection of Pesticides in Water by Direct Injection Liquid Chromatography-Tandem Mass Spectrometry / 分析化学

Effects of microfiltration membrane adsorption for eight types of pesticides with diverse physicochemical properties on direct injection liquid chromatography-tandem mass spectrometric method ( DI-LC-MS/MS) were investigated. The results showed that the adsorption effects ( AE,%) on the loss of signal detection at concentration of 2. 5 μg/L ranged from 8%-92%, 0%-81% and 2%-59% for nylon (NYL), polyethersulfone ( PES) and hydrophilic polypropylene ( GHP) membrane, respectively ( accumulated volume of feed is 1 mL). The pesticides with higher octanol-water partition coefficient (lgKow) values appeared to adsorb onto the membrane surface more readily than those with lower lgKow. The AE was found to be alleviated as the feed volume of samples increased to 10 mL, except the case of profenofos adsorption on PES membrane ( AE=9%) . The effects of PES membrane on the eight pesticides at initial individual concentration of 0 . 25 , 2. 5 and 25 μg/L were also studied. The results showed that, the lower the initial concentration of pesticides, the stronger adsorption effect under the same filtration conditions was obtained. Besides, it was effective in eliminating the membrane adsorption effects by adding 40% methanol ( V/V) into water samples as a modifier, which could consequently improve the accuracy of DI-LC-MS/MS.

Study on influencing factors of membrane flux and membrane fouling resistance in microfiltration of water extract of Cassia Semen / 中草药

Objective: To study the influencing factors of membrane flux (J) and membrane fouling resistance (Rf) in the mincrofiltration of the water extract of Cassia Semen with ceramic membrane. Methods: Based on single-factor experiment, the process parameters in the mincrofiltration of the water extract of Cassia Semen were optimized by orthogonal design method using weighted composite score of Rf and J as evaluation. The correlation between Rf and J with main four process parameters was analyzed. Results: The best microfiltration process condition was as follow: Membrane aperture size was 0.2 μm, concentration of the water extract of Cassia Semen was 50.0 g/L, transmembrane differential pressure was 0.1 MPa, and crossflow velocity was 3.32 m/s. Membrane aperture size had a significant correlation with Rf and J. Conclusion: The process parameters have an important effect on Rf and J. The primary and secondary order of the effect of four process parameters on Rf and J is as follow: Membrane aperture size > transmembrane pressure > feed concentration > crossflow velocity.

An increasing of the efficiency of microbiological synthesis of 1, 3-propanediol from crude glycerol by the concentration of biomass

Background 1,3-Propanodiol (1,3-PD), is used in the production of polytrimethylene terephthalate (PTT), an aromatic polyester that exhibits high elastic recoveries. It is also employed as a supplement with low solidification properties, a solvent and a lubricant in the formof propylene glycol. 1,3-PD is effectively synthesized by a microbiological way from crude glycerol. The main problem of this technology is using a high concentration of glycerol, which is a limiting factor for bacteria cells growth (especially in batch fermentation). Results In this work, the influence of different glycerol concentration in batch fermentation on Clostridium butyricum DSP1 metabolism was investigated. The biomass was concentrated for two times with the use of membrane module (in case of increasing kinetic parameters). Increased optical density of bacteria cells six times increased the productivity of 1,3-PD in cultivation with 20 g/L of glycerol at the beginning of the process, and more than two times in cultivation with 60-80 g/L. Also the possibility of complete attenuation of 140 g/L of crude glycerol in the batch fermentation was investigated. During the cultivation, changes of protein profiles were analyzed. The most significant changes were observed in the cultivation in the medium supplemented with 80 g/L of glycerol. They related mainly to the DNA protein reconstructive systems, protective proteins (HSP), and also the enzymatic catalysts connected with glycerol metabolic pathway. Conclusions The application of filtration module in batch fermentation of crude glycerol by C. butyricum DSP1 significantly increased the productivity of the process.

Avaliação do emprego de microfiltração para remoção de fibras do efluente de branqueamento de polpa celulósica / Evaluation of the use of microfiltration for removal of fiber from bleaching pulp mill effluent

O processo de branqueamento é o estágio em que ocorre a maior perda de fibras durante a fabricação de polpa celulósica. Além de ser uma perda de produto, estas fibras aumentam a concentração de matéria orgânica do efluente dificultando seu tratamento. O objetivo deste trabalho foi avaliar o emprego de microfiltração (MF) na remoção de fibras de efluente de branqueamento alcalino de polpa celulósica. Foi empregada membrana de poli(éter imida) com tamanho médio de poros de 0,5 µm e área de filtração de 0,05 m². O efeito das condições operacionais no fluxo permeado foi avaliado através do monitoramento do perfil de fluxo durante a operação em diferentes condições de velocidade de escoamento (Reynolds de 1.226, 1.653 e 2.043), pH da alimentação (7, 10 e 10,6), temperatura (28, 43 e 48°C) e pressão de operação através da avaliação da pressão crítica. Os resultados mostraram que a MF é um processo eficiente para remoção de fibras, apresentado 99% eficiência de remoção de sólidos suspensos. O melhor desempenho da operação de MF foi obtido empregando pH 7, pressão de 1 bar e Re de 1.653. Os resultados mostram que a redução do fluxo se deve principalmente à formação de torta.

The bleaching process is the stage where there is the greatest loss of fibers during the pulp production. Besides being a waste of product, these fibers increase the concentration of organic matter in the effluent and make the treatment of effluent more difficult. The aim of this study was to evaluate the use of microfiltration (MF) in the removal of fiber of effluent of alkaline bleaching pulp mill. The membrane employed was hollow fiber poly (ether imide), with average pore size of 0.5 µm and filtration area of 0.05 m². The effect of operating conditions on the permeate flux was evaluated by monitoring the flux profile during operation in different conditions of flow velocity (Reynolds 1,226, 1,653 and 2,043), pH of feeding (7, 10 and 10.6), temperature (28, 43, and 48°C) and pressure operation by evaluating the critical pressure. The results showed that MF is an efficient process for removal of fiber, with 99% removal efficiency of suspended solids. The best performance of the operation of MF was obtained using pH 7, 1 bar and Reynolds number of 1,653. The results show that the flow reduction is mainly due to cake formation.

Evaluación del sellado apical de tres técnicas de obturación en presencia de instrumentos rotatorios de NiTi fracturados / Assessment of apical sealing of three warm obturation techniques in the presence of fractured NiTi rotary instruments

El propósito de este estudio fue comparar la capacidad de sellado de tres técnicas de obturación con gutapercha termoplastificada, técnica de obturación vertical de Schilder, compactación termomecánica y Thermafil (Dentsply-Maillefer), en dientes con instrumentos fracturados en la región apical. Un total de 30 dientes unirradiculares extraídos fueron instrumentados con ProTaper (Dentsply-Maillefer), en cada uno de los mismos se fracturaron intencionalmente instrumentos rotatorios ProTaper F3 en el tercio apical. Los dientes fueron divididos aleatoriamente en tres grupos (n = 10) para ser obturados con la técnica correspondiente, para que, con la técnica de filtración de colorante y con la ayuda de la aclaración de los dientes fueran observados bajo microscopio para determinar la cantidad de microfiltración apical que permitía cada técnica. En todos los grupos, los especímenes presentaron alguna cantidad de microfiltración apical. Los dientes que fueron obturados con Thermafil presentaron una microfiltración promedio de 3,134 μm, resultando en significativamente mayor microfiltración que los obturados con la técnica termomecánica de McSpadden y de compactación vertical de Schilder, (p < 0.05) que obtuvieron un promedio de microfiltración de 1,934 μm y 2,083 μm respectivamente. Mientras que no existe diferencia estadísticamente significativa de microfiltración entre la técnica de McSpadden y la de Schilder (p > 0.05).

The purpose of the present study was to compare the sealing ability of three warm obturation techniques (thermo-plasticized gutta-percha): Schilders warm vertical compaction, McSpadden's thermo-mechanical compaction and Thermafil (Dentsply-Maillefer) in teeth fractured at the apical region. 30 extracted, single-rooted teeth were prepared with Pro-Taper (Dentsply-Maillefer). At the apical third of each of these teeth, ProTaper F3 rotary instruments were deliberately fractured. Teeth were randomly divided into three groups (n = 10) to be later filled with the selected technique, so that with dye penetration technique and with the aid of discoloring teeth technique, teeth could be microscopically assessed so as to determine the amount of apical microfiltration elicited in every technique. In all groups, specimens presented some degree of apical microfiltration. Teeth filled with Thermafil presented 3,134 µm average microfiltration. This microfiltration was significantly higher than the one observed with McSpadden thermo-mechanical technique and Schilder's vertical compaction technique (p < 0.05). These two techniques presented 1,934 µm and 2,083 µm respectively. McSpadden and Schilder's technique show no statistically significant microfiltration differences (p > 0.05).

Acceptance of microfiltered milk by consumers aged from 7 to 70 years

Microfiltration of milk reduces its microbial load providing a longer shelf life and preserving its nutritional and sensory characteristics. The present study compared the effect of the microfiltration treatment and of the milk pasteurization regarding the sensory acceptability by consumers aged from 7 to 70 years using a 7-point hedonic scale. The obtained results were evaluated by variance analysis and Duncan’stest. Microbiological, acidity, instrumental color and heat treatment extent analyses were also performed. Microfiltered milk showed a higher microbial counting reduction and lower acidity; and lesser change incolor coordinates was found when compared to pasteurized milk, indicating the lack of reactions causedby heating. In the sensory acceptability, two groups were formed (p > 0.05) for microfiltered milk, being a group consisted of children, adolescents and elderly, who rated the highest sensory scores, and these cond one formed by adults. Comparing the two kinds of milk, pasteurized and microfiltered samples, no difference in the acceptation was found only in the group constituted by children. These findings highlights the importance in assessing the sensory quality of milk, seeing that the sensory perception is linked with the consumer purchase choice.

Dimensionamiento del sistema de microfiltración para la producción de la Vacuna Pertussis elaborada en el Instituto Nacional de Higiene “Rafael Rangel” / Microfiltration sistem dimension for using in Pertussis Vaccine toxin production in the Instituto Nacional de Higiene "Rafael Rangel"

Se evaluó el uso de la tecnología de Flujo de Filtración Tangencial (FFT), para obtener la Vacuna Pertussis Celular a partir de cultivos de la bacteria Bordetella pertussis, usando el proceso de Microfiltración (MF) a objeto de recuperar el paquete celular. Se determinaron las características de los filtros, condiciones de trabajo y el dimensionamiento del equipo a adquirir para la nueva producción in dustrial de Vacuna Pertussis Celular. Se evaluaron el flujo y tiempo de proceso, rendimiento y las características del producto obtenido. Utilizando cultivos con Vacuna Pertus sis en un equipo de filtración de laboratorio, diseñado para producir el efecto de FFT. Se seleccionó las membranas tipo cassettes, formato Suspended Screen, porosidad 0,2 μm, como las adecuadas para el proceso de MF, ya que mostraron un 100% de recuperación del paquete celular sin transmisión de células al filtrado y con un flujo promedio de filtrado de 54.00 L/m2h. Estos resultaron permitieron dimensionar, considerando las variables a utilizar en la nueva producción industrial (Volumen 650 Litros, Tiempo de Procesos, 3 a 4 horas), el área de filtración del equipo de MF a adquirir, estimado en 20 m² .

Tangential Flow Filtration (TFF) technology was evaluated to process Whole Cell Pertussis Vaccine which is produced by Bordetella pertussis bacterium. Microfiltration (MF) is used to recovery cells to produ ce the vaccine. MF pro - cesses was evaluated to specify the filters and corresponding critical process parameters to scale-up the application. As part of the evaluation, flow rate, processing time, yield and product attributes were characterized. The cell harvest con taining the Whole Cell Pertussis was processed using a laboratory scale TFF system designed to pro duct the TFF effect. The evaluation demonstrated that a cassette in suspended screen format and membrane with 0.2μm pore is the right selection for the MF step. It showed 100% of cell recovery without cell transmission to the filtrate and average process flux of 54.00 L/m2h. These results were used to scale-up the application to process the industrial volume of 650 liters in 3 hours of processing time. Membrane area sizing of MF to be acquired is estimated in 20 m².

Beer Clarification with polysulfone membrane and study on fouling mechanism

The aims of the present work were to study the relationship between the fluxes, permeate quality, and fouling mechanism. A polysulfone membrane with 100 KDa and 0.12 m² of surface area was used. Permeate fluxes were measured for different pressures (0.5, 1.0, 1.5, and 2.0 bar) at the same temperature of 8 ºC. The fluxes measured for each pressure ranged from 22, 24, 27 and 30 kg h-1m-2 at 0.5, 1.0, 1.5 and 2.0 bar, respectively. Samples of the feed and permeate were analyzed for pH, color, turbidity, sugar, bitterness, and proteins. The fouling mechanisms observed were cake filtration, partial pore blocking, and complete pore blocking.

Avaliação da microfiltração para remoção do lodo gerado no processo oxidativo avançado empregando o reagente de Fenton no tratamento de lixiviado de aterro sanitário / Evaluation of microfiltration for removal of sludge generated in advanced oxidation process by Fenton reagent in treatment of landfill leachate

Uma alternativa atrativa para o tratamento de lixiviado de aterro sanitário são os processos oxidativos avançados empregando o reagente de Fenton (POA/Fenton). No entanto, a aplicação do POA/Fenton é limitada pela geração de lodo no processo. Esse lodo possui elevada concentração de ferro, o que torna necessária sua separação do efluente tratado. O objetivo desse trabalho foi avaliar a microfiltração para a remoção de lodo gerado no POA/Fenton. A pesquisa foi desenvolvida em unidade de bancada. O POA/Fenton apresentou elevada eficiência na remoção de matéria orgânica (75 por cento) e cor real (95 por cento). O processo de microfiltração foi eficiente na separação do lodo gerado, o qual apresentou baixa sedimentabilidade, dificultando sua separação por sedimentação, além de ter contribuído para a remoção de outros poluentes.

Advanced oxidation processes using Fenton's reagent (AOP/Fenton) are an attractive alternative for landfill leachate treatment. However, the implementation of the AOP/Fenton is limited by the generation of sludge in the process. The sludge has a high iron concentration, which needs its separation from the treated effluent. The aim of this study was to evaluate the microfiltration for sludge removal from an AOP/Fenton. The work was conducted in bench scale. The advanced oxidation process showed high efficiency in removing organic matter (75 percent) and true color (95 percent). The microfiltration was effective in separating the sludge, which showed low settling hindering their separation by sedimentation, and has contributed to the removal of other pollutants.