Characterization of fillets of Amazon and real hybrid sorubins / Caracterización de filetes de sorubinas híbridas amazónica y real

Background: Many fish hybrids (i.e., obtained by crossing two species) are produced rather than pure species because of their better growth rate and/or acceptance of formulated feed. However, few studies evaluate and compare their meats and acceptance, including, e.g., for the Amazon hybrid sorubim (Pseudoplatystoma reticulatum x Leiarius marmoratus) and the real hybrid sorubim (Pseudoplatystoma corruscans x L. marmoratus). Objective: Thus, this work aimed to evaluate the physical, chemical, microbiological, and sensory characteristics of fillets from the Amazon and real hybrid sorubins. Method:Proximate composition, instrumental color, water holding capacity, cooking losses, and shear force were measured.Microbiological analyses of the fillets were carried out for Salmonellasp. and Staphylococcusaureus to ensure food safety during sensory analysis. Results: Fillets presented excellent quality, classified in category A (lipids below 5% and proteins between 15 and 20%). There was no significant difference (p>0.05) between the evaluated fillets for several parameters: the average water holding capacities were 33.72 and 34.67%, the cooking losses were 14.93 and 13.41%, the shear forces were 2.21 and 1.74 kgf, and the luminosities were 49.61 and 45.04 for the fillets of Amazonian hybrid sorubim and real hybrid sorubim, respectively. Discussion: There was an evident relationship between water-holding capacities and shear forces. Amazonian hybrid sorubim fillets presented lower intensity of red. However, there was no sensory difference between the hybrids, and both had an acceptance rate above 80%. Conclusion: The hybridization does not alter the characteristics of the fish fillets

Antecedentes: Muchos híbridos de peces (i.e., obtenidos al cruzar dos especies) se producen en lugar de especies puras debido a su mejor tasa de crecimiento y/o aceptación de alimentos formulados. Sin embargo, pocos estudios evalúan y comparan sus carnes y aceptación, incluyendo, p. ej., para lo surubí híbrido amazónico (Pseudoplatystoma reticulatum x Leiarius marmoratus) y lo surubí híbrido real (Pseudoplatystoma corruscans x L. marmoratus). Objetivo: Así, el objetivo de este trabajo fue evaluar las características físicas, químicas, microbiológicas y sensoriales de filetes sorubines híbridos amazónico y real. Método: Se midió composición proximal, color instrumental, capacidad de retención de agua, pierdas por cocción y fuerza de corte. Se realizaron análisis microbiológicos de los filetes para Salmonella sp. y Staphylococcus aureus para garantizar la seguridad alimentaria durante el análisis sensorial. Resultados: Los filetes presentaron una excelente calidad, siendo clasificados en la categoría A (lípidos por debajo del 5% y proteínas entre 15 y 20%). No hubo diferencia significativa (p>0.05) entre los filetes evaluados para varios parámetros: las capacidades de retención de agua fueron 33.72 y 34.67%, las pierdas por cocción fueron 14.93 y 13.41%, las fuerzas de corte fueron 2.21 y 1.74 kgf y las luminosidades fueron 49.61 y 45.04 para los filetes de sorubim híbrido amazónico y sorubim híbrido real, respectivamente. Discusión: Hubo una relación evidente entre las capacidades de retención de agua y las fuerzas de corte. Los filetes de sorubim híbridos amazónicos presentaron menor intensidad de rojo. Sin embargo, no hubo diferencia sensorial entre los híbridos, y ambos tuvieron una tasa de aceptación superior al 80%. Conclusión: La hibridación no altera las características de los filetes de pescado

Análise de metodologias para avaliação da solubilidade do cimento à base de silicato de cálcio Bio-C Sealer / Analysis of methodologies for evaluating the solubility of calcium silicate-based sealer Bio-C Sealer

Introdução: Cimentos endodônticos à base de silicato de cálcio demonstram maior solubilidade em água destilada. Emprego de metodologias alternativas pode auxiliar em melhor compreensão sobre a solubilidade desses materiais. Objetivo: Avaliar o efeito da solução de imersão e do tipo de modelo experimental na solubilidade de cimento pronto para uso Bio-C Sealer. Material e método: Modelos circulares de polietileno ou dentina bovina (n = 16) foram confeccionados. Após inserção do cimento, os espécimes foram mantidos em estufa a 37 °C por 48 horas. Posteriormente, as amostras foram pesadas em balança de precisão para determinação da massa inicial. Na sequência, os espécimes foram imersos em 7,5 mL de água destilada (pH 6,5) ou PBS (pH 7,0) (n = 8) por 28 dias. Após isso, as amostras foram removidas das soluções e pesadas a cada 24 horas até a estabilização da massa final (0,001g). Corpos de prova confeccionados com Bio-C Sealer foram empregados como controle. A solubilidade foi avaliada de acordo com a diferença entre a massa inicial e final em porcentagem. Teste ANOVA Two-Way e teste post-hoc de Tukey foram realizados (α = 0,05). Resultado: Imersão em água destilada proporcionou maior solubilidade em comparação com PBS, independentemente do modelo experimental (p < 0,05). Corpos de prova apresentaram maior solubilidade, seguidos dos modelos de polietileno e dentina imersos em água destilada (p < 0,05). Não houve diferença entre os modelos experimentais imersos em PBS (p > 0,05). Conclusão: Bio-C Sealer apresenta solubilidade significativamente maior em água destilada do que em PBS em todas condições. Modelo experimental empregando dentina bovina e PBS como solução de imersão demonstra diminuir a perda de massa de Bio-C Sealer e pode ser uma alternativa valiosa para avaliar a solubilidade de cimentos biocerâmicos

Introduction: Calcium silicate-based sealers demonstrate greater solubility in distilled water. The use of alternative methodologies can help at better understanding the solubility of these materials. Objective: To evaluate the effect of the immersion solution and the type of experimental model on the solubility of readyto-use Bio-C Sealer. Material and method: Circular models of polyethylene or bovine dentin (n = 16) were made. After insertion of the sealer, the specimens were kept in an oven at 37°C and 95% humidity for 48h. Subsequently, the samples were weighed on a precision balance to determine the initial mass. Next, the specimens were immersed in 7.5 mL of distilled water (pH 6.5) or PBS (pH 7.0) (n = 8) for 28 days. After that, the samples were removed from the solutions and weighed every 24 hours until the final mass stabilized (0.001g). Test specimens made with Bio-C Sealer were used as a control. Solubility was evaluated according to the difference between the initial and final mass in percentage. Two-Way ANOVA test and Tukey post-hoc tests were performed (α=0.05). Result: Immersion in distilled water provided greater solubility compared to PBS regardless of the experimental model (p<0.05). The test specimens showed greater solubility, followed by polyethylene and dentin models immersed in distilled water (p<0.05). There was no difference between the experimental models immersed in PBS (p>0.05). Conclusion: Bio-C Sealer presents significantly greater solubility in distilled water than in PBS under all conditions. Experimental model using bovine dentin and PBS as an immersion solution demonstrates reduction in the mass loss of Bio-C Sealer and can be a valuable alternative for evaluating the solubility of bioceramic sealers

A new proposal for evaluating of the solubility of bioceramic materials in dentin tubes after immersion in PBS: a laboratory investigation / Nova proposta para avaliação da solubilidade de materiais biocerâmicos em tubos de dentina após imersão em PBS: um estudo laboratorial

Introdução: Materiais reparadores devem apresentar baixa solubilidade. Solução salina tamponada com fosfato (PBS) permite simular condição clínica e interação com dentina pode ser importante para correta avaliação da perda de massa de cimentos biocerâmicos. Objetivo: Avaliou o efeito da imersão em água destilada (AD) ou PBS na solubilidade de Bio-C Repair (BCR, Angelus) ou MTA Repair HP (MTAHP, Angelus) usando modelo de tubo de dentina. Material e método: Tubos de dentina bovina foram confeccionados com 4 mm de comprimento, 1,5 mm de diâmetro interno e 1 mm aproximadamente de espessura de parede. Os espécimes foram imersos em AD por 24h, posteriormente preenchidos com BCR ou MTAHP (n = 14) e armazenados em estufa a 37°C e umidade 95% por 24h. Após serem pesados em balança de precisão para determinação da massa inicial, os corpos de prova foram imersos em AD (pH 6,5) ou PBS (pH 7,0) (n = 7) por 28 dias. Tubos vazios também foram utilizados para o cálculo de perda de massa da dentina (n=4). Após esse período, os espécimes foram pesados até a estabilização da massa final (0,001g). A solubilidade de cada material foi avaliada. Testes estatísticos ANOVA e Tukey foram realizados (α=0,05). Resultado: BCR e MTAHP apresentaram ganho de massa em AD e perda de massa em PBS (p<0,05). Conclusão: A solução de imersão influencia a solubilidade de BCR e MTAHP usando modelo de tubo de dentina. Nova proposta metodológica poderá ser uma alternativa às normas ISO para testar a solubilidade de cimentos biocerâmicos

Introduction: Repair materials must have low solubility. Phosphate buffered saline (PBS) allows simulating clinical condition and interaction with dentin may be important for the correct evaluate of mass loss of bioceramic cements. Objective: To evaluate the effect of distilled water (DW), or PBS immersion on the solubility of Bio-C Repair (BCR, Angelus) or MTA Repair HP (MTAHP, Angelus) using a dentin tube model. Material and method: Bovine dentin tubes with a length of 4 mm, an internal diameter of 1.5 mm and walls thickness of approximately 1 mm were made. The specimens were immersed in DW for 24h, then filled with BCR or MTAHP (n = 14) and stored in an oven at 37°C and 95% humidity for 24h. After being weighed on a precision balance to determine the initial mass, the specimens were immersed in DW (pH 6.5) or PBS (pH 7.0) (n = 7) for 28 days. Empty tubes also were used for calculating the mass loss of the dentin (n=4). After this period, the specimens were weighed until stabilization of the final mass occurred (0.001g). The solubility of each material was evaluated. ANOVA and Tukey statistical tests were performed (α=0.05). Result: BCR and MTAHP showing gain of mass in DW and mass loss in PBS (p<0.05). Conclusion: The immersion solution influenced the solubility of BCR and MTAHP using dentin tube model. The new methodological proposal could be an alternative to ISO standards for testing the solubility of bioceramic cement

Comparative of flexural strength, hardness, and fluoride release of two bioactive restorative materials with RMGI and composite resin

Aim: This study was fulfilled to evaluate the flexural strength, micro-hardness, and release of two fluoride ions of bioactive restorative materials (Cention N and Activa Bioactive), a resin modified glass ionomer (Fuji II LC), and a resin composite (Filtek z250). Methods: Forty samples from four restorative materials (Activa Bioactive, Fuji II LC, Cention N, and Filtek Z250) were provided according to the current standards of ISO 4049/2000 guide lines. Subsequently, the samples were stored for 24 hours and 6 months in artificial saliva, and successively, flexural strength and micro-hardness of the samples were measured. For each studied groups the pH was decreased from 6.8 to 4 in storage solution. The rate of changes in fluoride ion release was measured after three different storage periods of 24 hours, 48 hours, and 6 months in distilled water, according to the previous studies' method. Two-way ANOVA, One-way ANOVA, Tukey HSD Pair wise comparisons, and independent t-tests were used to analyze data (α= 0.05). Results: The highest flexural strength and surface micro-hardness after 24 hours and also after 6 month were observed for Cention N(p<0.001).Flexural strength of all samples stored for 6 months was significantly lower than the samples stored for 24 hours(p<0.001). The accumulative amount of the released fluoride ion in RMGI, after six-month storage period in distilled water was considerably higher (p<0.001) than 24 hours and 48 hours storage. The amount of fluoride ion release with increasing acidity of the environment (from pH 6.8 to 4) in Fuji II LC glass ionomer was higher than the bioactive materials (p<0.05). Conclusion: The flexural strength of RMGI was increased after storage against the Activa Bioactive,Cention N and Z250 composite. Storage of restorative materials in artificial saliva leads to a significant reduction in micro hardness. The behavior and amount of released fluoride ions in these restorative materials, which are stored in an acidic environment, were dependent on the type of restorative material

Castor Bean Cake Protein-based Biodegradable Films: Gallic Acid Effect

Abstract: The objective of this work was to evaluate the effect of gallic acid (GA) concentration on some physical properties and biodegradability of films produced with proteins extracted from the castor bean cake. The films, prepared by the casting technique, showed homogeneous and brownish appearance. As the GA concentration increased (from 0 to 10 g/100 g protein), the films gradually became darker and more opaque; while the gloss had few significant differences. Solubility, tensile strength and elasticity modulus values of films varied due to changing concentrations of gallic acid. Elongation at break and water vapor permeability values did not have significant changes. A 60% mineralization value of the film containing GA was obtained at 21 days, evidencing its biodegradability. These dark and opaque films could be used in agriculture, specifically in seedling bags as the dark color decrease the incidence of light, preventing root weakening, and the seedlings can be transplanted directly without removal of the film.

Relative humidity, temperature, substrate type, and height of terrestrial lichens in a tropical paramo / Humedad relativa, temperatura, tipo de sustrato y altura de los líquenes del suelo en un páramo tropical

Abstract Lichens are traditionally divided into types such as "crustose", "foliose" and "fruticose", with different shapes and heights. Substrate, temperature and water are thought to affect lichen height, but there are few studies regarding tropical paramo lichens. Along 2015 I measured those variables in the terricolous lichens of the Cerro Buena Vista, paramo (Costa Rica, 9°33' N & 83°45' W). The measurements were taken inside the lichens and in the substrate under them, in 61 randomly located quadrats (50 x 50 cm). Lichens grew taller on (1) warmer ground, (2) wetter ground, (3) the moister Caribbean slope, and (4) the season with heavier rainfall, as expected. Apparently, atmospheric factors are more important than substrate in the determination of temperature, relative humidity and growth of lichens. Physiologically available water seems to be the main determinant of lichen vertical growth in the Buena Vista paramo.(AU)

Resumen Los líquenes se dividen tradicionalmente en morfotipos como "crustoso", "folioso" y "fruticoso", con diferentes formas y alturas. Se cree que el sustrato, la temperatura y el agua afectan la altura de los líquenes, pero existen pocos estudios con respecto a los líquenes tropicales. A lo largo del 2015, medí esas variables en los líquenes del suelo en el páramo de Cerro Buena Vista (Costa Rica, 9 ° 33'N; 83 ° 45'W). Las medidas se tomaron dentro de los líquenes y en el sustrato debajo de ellos, en 61 cuadrantes ubicados al azar (50 x 50 cm). Los líquenes fueron más altos en (1) suelo más cálido, (2) suelo más húmedo, (3) la pendiente del Caribe, que es más húmeda y (4) la temporada con lluvias más intensas, como se esperaba. Aparentemente, los factores atmosféricos son más importantes que el sustrato en la determinación de la temperatura, la humedad relativa y el crecimiento de los líquenes. El agua fisiológicamente disponible parece ser el principal determinante del crecimiento vertical de los líquenes en el páramo del Cerro Buena Vista.(AU)

Características físicas e microbiológicas de compostagem de resíduos animais / Physical and microbiological characteristics process of composting waste from animals

Objetivou-se com o presente trabalho caracterizar o processo de compostagem de fluxo contínuo e aeração passiva de resíduos da produção e abate da caprino-ovinocultura e de seu composto orgânico gerado. O processo de compostagem utilizou resíduos sólidos provenientes da produção e do abate de caprinos e ovinos e foi realizado em galpão de alvenaria. Os resíduos agropecuários utilizados incluíram sobras de capim-elefante triturado seco, poda de árvores, esterco e carcaça de caprinos e ovinos. Os tratamentos empregados foram três níveis de umidade aplicados nas leiras de compostagem (30, 50 e 70% com base no peso da carcaça dos animais) e épocas do ano de montagem (período seco, transição e úmido) com base na precipitação, com três repetições. As variáveis avaliadas foram atributos químicos, físicos, microbiológicos e parasitológicos do composto e sua comparação com a legislação vigente. O composto orgânico gerado atende as especificações das legislações utilizadas para comparação. Independentemente da época do ano ou da umidade aplicada, o processo de compostagem foi eficiente em reduzir passivos ambientais, como carcaças. A compostagem promoveu a eliminação dos patógenos avaliados, indicando que o composto não oferece risco de transmissão e pode ser utilizado de forma segura.(AU)

The objective of this study to characterize the process of continuous flow of composting and passive aeration of waste production and slaughter the goat and sheep industry and its generated organic compound. The composting process, performed in a brick barn, used solid residues (manure and carcass parts) from the slaughter of goats and sheep along with chopped dry elephant grass and tree trimmings. The treatments employed three moisture levels in the piles and four collections of samples from the piles at timed intervals (0, 30, 60 and 120 days), with three repetitions. The variables evaluated were the chemical and physical attributes of the compost generated. The treatments were three moisture levels applied in compost piles (30, 50 and 70% based on the housing of animals) and assembly times of the year (dry, transitional and humid) based on rainfall, with three replications. The variables were chemical, physical, microbiological and parasitological of the compound and its comparison with current legislation. The generated organic compound meets the specifications of the laws used for comparison. Regardless of the time of year or moisture applied, the composting process was effective in reducing environmental liabilities as carcasses. Composting promoted elimination of this pathogen, indicating that the compound can be used safely.(AU)

Avaliação do manchamento e da rugosidade superficial de materiais restauradores diretos após diferentes sistemas de polimento: estudo in vitro / Assessment of surface staining and roughness of direct restorative materials after different polishing systems: in vitro study

Resumo Introdução Com o avanço estético e tecnológico dos compósitos restauradores diretos, a procura pela Odontologia Éstética tem aumentado. Objetivo Avaliar o manchamento e a rugosidade superficial dos compósitos Filtek Z350 (3M ESPE) e Filtek Bulk Fill (3M ESPE), polidos por diferentes sistemas: Disco SofLex e Disco SofLex diamantado espiral (ambos da 3M ESPE), após exposição repetitiva ao café. Material e método Neste estudo in vitro, um total de 80 discos de resina foi confeccionado, com 40 espécimes para cada compósito avaliado. Os espécimes foram ainda subdivididos em grupos (n=10) de acordo com o método de polimento ‒ SofLex e SofLex diamantado ‒ e a solução de armazenamento ‒ água deionizada (controle) e café (experimental). Após 24 horas de armazenamento em água deionizada, foi realizada a avaliação de cor e rugosidade inicial, bem como a execução dos protocolos de polimento testados. Posteriormente, os espécimes foram expostos ao processo de manchamento em café e água deionizada durante 42 dias. Após esse período, a cor e a rugosidade foram reavaliadas. Resultado A análise estatística paramétrica evidenciou que o manchamento superficial foi influenciado significativamente pelos fatores compósito e solução, mas não pelo fator polidor ou ainda por qualquer interação entre os fatores. Para o fator compósito, Filtek Z350 exibiu maior manchamento, e para o fator solução, foi observado maior manchamento para o café. Já na análise de rugosidade, não houve diferenças significativas. Conclusão Independentemente do sistema de polimento, a solução experimental de café alterou a cor de ambos os compósitos avaliados e verificou-se que a rugosidade não foi alterada.

Abstract Introduction The aesthetic and technological development of direct restorative composites has increased the search for an aesthetic dentistry. Objective Assess the surface staining and roughness of composites: Filtek Z350 (3M ESPE) and Filtek Bulk Fill (3M ESPE), polished by different systems: Disco SofLex and Disco SofLex diamond spiral (both from 3M ESPE), after repeated exposure to coffee. Material and method This study was carried out together with 80 resin discs were made, 40 articles for each study evaluated. The compounds were divided into groups (n = 10) according to the polishing method - Softex and Softex diamond, storage solution - deionized water (control) and coffee (experimental). After 24 hours of storage in deionized water, a color evaluation was performed initially, as well as the execution of the polishing protocols tested. Subsequently, the specimens were exposed to the staining process in coffee and deionized water for 42 days. After this period, the color and roughness were assessed again. Result The parametric statistical analysis showed that surface staining was affected significantly by the composite and solution factors, but not by the polisher factor or by any interaction among factors. For the composite factor, Filtek Z350 showed greater staining and for the solution factor, coffee showed greater staining. In contrast, the roughness analysis did not show significant differences. Conclusion Regardless of the polishing system, differences in composite composition affect the color stability of the composites; and coffee changes the color of both; the roughness was not altered.

Effect of diphenyliodonium hexafluorphosphate in the yellowing and properties of experimental resin cements

Aim: The yellowing effect is undesirable and can occur in the dental restoration margins when light-cured resin cements containing camphorquinone as photoinitiator is used. This study aimed to evaluate the effect of diphenyliodonium hexafluorphosphate (DPI) in photoinitiator systems that contained different concentrations of camphorquinone (CQ) and dimethylamino ethyl benzoate (EDAB) on resin cements. Methods: A base (1:1) of bisphenol A diglycidyl methacrylate (BisGMA) and triethylene glycol dimethacrylate (TEGDMA) was obtained, and 60wt% of glass fillers was added. Eight formulations were obtained: RC1 (0.5mol% CQ / 1mol% EDAB), RC2 (0.5mol% CQ / 2mol% EDAB), RC3 (1mol% CQ / 1mol% EDAB), RC4 (1mol% CQ / 2mol% EDAB), and RC5 to RC8, which contained the same bases plus 0.5mol% DPI. Experimental resin cements were evaluated by the degree of conversion (DC), L*a*b* color analysis, water sorption (WS) and solubility (S), flexural strength, and Elastic Modulus. The data were analyzed by three-way ANOVA, Tukey's and Mann-Whitney tests (α = 0.05). Results: The combination of DPI and 0.5mol% CQ increased DC in RC6 and L* in RC5 without increasing the WS and a* b* values. CQ at 1mol% showed higher values of b* and lower values of a*, except for RC3. Groups with 2mol% EDAB showed higher DC. Conclusion: The addition of DPI reduces CQ, generating a decreased yellowing effect, while maintaining adequate properties in the resin cements, especially with 2mol% EDAB

Radiopacity and Chemical Assessment of New Commercial Calcium Silicate-Based Cements / Radiopacidad y Evaluación Química de Cementos Comerciales en Base a Silicato de Calcio

ABSTRACT: The aim of the study was to evaluate the chemical composition and radiopacity of new calcium-silicatebased cements. Discs of 10 mm x 1 ± 0.1mm were prepared of BiodentineTM, TheraCal, Dycal and GC Fuji IX (n=5). The samples were radiographed directly on an PSP occlusal plate adjacent to an aluminium step wedge. The radiopacity of each specimen was determined according to ISO 9917/2007. Statistical analyses were carried out using ANOVA and Tukey's test at a significance level of 5 %. The chemical constitution of materials was determined by scanning electron microscopy (SEM) and energy dispersive x-ray element mapping. The radiopacities of the materials in decreasing order were: GC Fuji IX (3.45 ± 0.16 mm), Dycal (3.18 ± 0.17), BiodentineTM (2.79 ± 0.22), and TheraCal (2.17 ± 0.17). TheraCal showed the lowest radiopacity compared to the other materials, followed by BiodentineTM. Dycal and GC Fuji IX radiopacity values did not present significant statistical differences. Scanning electron microscopy and energy dispersive X-ray analysis revealed the presence of zirconium in BiodentineTM; and strontium, barium and zirconium in TheraCal as radiopacifying elements. The new calcium silicate cements present distinctive chemical composition. BiodentineTM contains zirconium as a radiopacifying element and has higher radiopacity values than TheraCal, which contains barium and strontium as radiopacifiers.

RESUMEN: El objetivo de este estudio fue evaluar la composición química y la radiopacidad de nuevos cementos en base a silicato de calcio. Discos de 10 mm x 1 ± 0,1 mm fueron preparados con BiodentineTM, TheraCal, Dycal y GC Fuji IX (n=5). Las muestras fueron radiografiadas directamente en una película PSP oclusal adyacente a una cuña escalonada de aluminio. La radiopacidad de cada espécimen fue determinada de acuerdo a la norma ISO 9917/ 2007. Se realizaron los análisis estadísticos con las pruebas ANOVA y test de Tukey con un nivel de significancia de 5 %. La constitución química de los materiales fue determinada con microscopía electrónica de barrido y con mapeo por análisis con dispersión de energía de rayos X. La radiopacidad de los materiales en orden decreciente fue: GC Fuji IX (3,45 ± 0,16 mm), Dycal (3,18 ± 0,7 mm), BiodentineTM (2,79 ± 0,22 mm), y TheraCal (2,17 ± 0,17 mm). TheraCal mostró la menor radiopacidad comparada con los otros materiales, seguido de BiodentineTM. Los valores de radiopacidad de Dycal y GC Fuji IX no presentaron diferencias estadísticas significativas. Los análisis de microscopía electrónica de barrido y mapeo por análisis con dispersión de energía de rayos X revelaron la presencia de zirconio en BiodentineTM; y de estroncio, bario y zirconio en TheraCal, como elementos radiopacos. Los nuevos cementos en base a silicato de calcio presentan una composición química distintiva. BiodentineTM contienen zirconio como elemento que provee radiopacidad y tiene mayor valor de radiopacidad que TheraCal, el cual contiene bario y estroncio como agente radiopaco.

Influence of Functional Clinical Temperature over Compressive Strength and Diametral Tensile Strength of Various Luting Cements

Objective: To estimate the effect of temperature over the physical properties of commonly used luting cements. Material and Methods: The two set of cylindrical shaped cement samples measuring 12mm X 6mm and 4mm X 8mm were fabricated from non-eugenol zinc oxide, glass ionomer, zinc phosphate, Zinc polycarboxylate, resin cements. These two sets of samples were utilized to test compressive and diametral tensile strength respectively. Forty cement samples from each mold were fabricated and distributed between 14, 22, 37 and 550C (N=10). The samples were tested under universal testing machine, and data subsequently analyzed using One-way ANOVA and Tukey multiple comparison's statistical methods at p > 0.05. Results: The higher temperature resulted in noticeable reduction in the compressive strength of non-eugenol -zinc oxide, Zinc-phosphate, Zinc poly carboxylate cements. The highest compressive strength was recorded for non-eugenol zinc oxide (8.08 Mpa) at 370C, Zinc phosphate (91.01Mpa) at 140C, and for zinc polycarboxylate (83.06 Mpa) at 370C. The comparative values for respective cements at 550C were 6.40Mpa, 59.80Mpa, and 52.88 Mpa. The higher temperature had insignificant effect on the compressive strength of glass ionomer cement, while composite resin cement indicated minor deterioration. Conclusion: The relative mouth temperature influences the physical properties of the luting cements.

Impacto de um método de polimento adicional em propriedades físicas, micromorfológicas e microtopográficas de compósitos convencionais e Bulk Fill / Impact of an additional polishing method on physical, micromorphological and microtopographical properties of conventional and Bulk Fill composites

O objetivo deste trabalho foi avaliar a rugosidade superficial, a molhabilidade, a disposição em profundidade das partículas de carga, o mapeamento de elementos químicos, a microtopografia em 3D e a micromorfologia de compósitos convencionais e bulk fill após polimento adicional. Éspécimes foram preparados de cada compósito testado, sendo quatro do tipo bulk fill (Filtek Bulk, Fill Tetric N-Ceram Bulk Fill, Opus Bulk Fill e X-tra Fil) e quatro convencionais (Filtek Z250 XT, Grandioso, Tetric NCeram, Vittra APS), de acordo com três técnicas de acabamento/polimento/polimento adicional (n = 10): sem acabamento e polimento, acabamento e polimento com borrachas abrasivas (Astropol), acabamento e polimento com Astropol mais polimento adicional com escova de carbeto de silício. A rugosidade superficial (Ra) e o ângulo de contato foram medidos usando-se um perfilômetro e goniômetro adaptado, respectivamente. A microtopografia 3D foi avaliada utilizando microscopia de força atômica (MFA), enquanto a micromorfologia e a disposição em profundidade das partículas de carga, através da microscopia eletrônica de varredura (MEV). O mapeamento de elementos químicos foi avaliado por meio de Espectroscopia por energia dispersiva de raio-X (EDS). A rugosidade e o ângulo de contato foram analisados pelo ANOVA-dois fatores e teste de Tukey (p <0,05); os demais dados foram analisados descritivamente. A disposição das partículas de carga em profundidade de todas as resinas envolvidas neste estudo apresentou uma camada superficial rica em matriz orgânica e uma camada subsuperficial rica em partículas de dimensões mais diminutas. O polimento adicional: diminuiu a rugosidade superficial das resinas Filtek Bulk Fill, Vittra APS, Tetric N-ceram Bulk Fill e X-tra fil; aumentou o valor do ângulo de contato da X-tra Fil e diminuiu da Filtek Z250 XT. Nas análises para microtopografia em 3D e a micromorfologia, superfícies mais lisas e uniformes foram observadas em todas as resinas. Os elementos: carbono (C), cxigênio (O), silício (Si), zircônia (Zr) e alumínio (Al) foram presentes em todas as resinas compostas. O bário (Ba) foi ausente na Filtek Z250 XT, Filtek Bulk Fil e Vittra APS. O carbono foi predominante em todas as resinas. Após polimento adicional, houve um aumento na detecção de oxigênio para todas as resinas, exceto para Tetric N-Ceram e Xtra Fil e uma diminuição de carbono, exceto para a Tetric N-Ceram Bulk Fil. O silício diminuiu apenas nas resinas Z250 XT, Tetric N-Ceram e Tetric N-Ceram Bulk Fill. A zircônia diminuiu para a Tetric N-Ceram Bulk Fill e o alumínio para Z250 XT e Tetric N-Ceram Bulk Fill. O bário aumentou para Opus Bulk fill e X-tra Fil. O titânio foi ausente para todas as resinas. Portanto, o polimento adicional melhorou as propriedades de superfície das resinas estudadas (AU).

The objective of this study was to evaluate the surface roughness, wettability, the depth distribution of the charge particles, the mapping of chemical elements, the 3D microtopography and the micromorphology of the composites of the conventional and bulk fill after additional polishing. The specimens were prepared from each of the composites tested, four of them being bulk fillers (Filtek Bulk Fill Tetric N-Ceram Bulk Fill Opus Bulk Fill X-tra Fil) and four conventional ones (Filtek Z250 XT, Grandioso, Tetric N-Ceram, Vittra APS ), according to three additional finishing / polishing / polishing techniques (n = 10): without finishing and polishing, finishing and polishing with abrasive rubbers (Astropol), finishing and polishing with Astropol plus additional polishing with silicon carbide brush. The surface roughness (Ra) and contact angles were measured using a profilometer and adapted goniometer, respectively. The 3D microtopography was evaluated using atomic force microscopy (AFM); while the micromorphology and the in-depth arrangement of the charge particles by scanning electron microscopy (SEM). The mapping of chemical elements was evaluated by means of X-ray Dispersive Energy Spectroscopy (EDS). The roughness and the contact angle were analyzed by ANOVA- two factors and Tukey test (p <0.05); the other data were analyzed descriptively. The arrangement of the in-depth charge particles of all the resins involved in this study had an organic matrix rich surface layer and a particulate rich subsurface layer of smaller dimensions. Addicional polishing: reduced surface roughness of Filtek Bulk Fill resins, Vittra APS, Tetric N-ceram Bulk Fill and X-trafil resins; increased the contact angle value of the X-tra Fil and decreased the Filtek Z250 XT. In the analyzes for 3D microtopography and micromorphology, smoother and more uniform surfaces were observed in all a resins. The elements: carbon (C), oxygen (O), silicon (Si), zirconia (Zr) and aluminum (Al) were present in all composite resins. Barium (Ba) was absent on Filtek Z250 XT, Filtek Bulk Fil and Vittra APS. Carbon was predominant in all resins. After additional polishing, there was an increase in oxygen detection for all resins except for Tetric N-Ceram and X-tra Fil and a decrease in carbon except for Tetric N-Ceram Bulk Fil. Silicon decreased only in the Z250 XT, Tetric N-Ceram and Tetric NCeram Bulk Fill resins. Zirconia decreased for Tetric N-Ceram Bulk Fill and aluminum for Z250 XT and Tetric N-Ceram Bulk Fill. Barium increased for Opus Bulk fill and X-tra Fil. Titanium was absent for all resins. Therefore, additional polishing improved the surface properties of the resins studied (AU).

Surface roughness, gloss and color change of different composites after exposure to ultimate challenges

Aim: The study aimed to investigate the effect of the association of chemical and mechanical degradation on the surface roughness, gloss and color of nano and microfilled composites. Method: Disc-shaped specimens (n=10) were prepared for three nanocomposites (Filtek Z350XT, IPS Empress Direct, Charisma Diamond) and three microfilled composites (Estelite Σ Quick, Durafill VS, Renamel). After polishing, baseline surface roughness, gloss and color measurements were obtained. Specimens were submitted subsequently to the following challenges: chemical for 1 week (Hydrochloric acid, Coca-Cola and Red Wine) and mechanical (Toothbrushing). Surface roughness and gloss data were analyzed by Kruskal-Wallis followed by Dunn's test. Color difference (ΔE) was analyzed by one-way ANOVA and Tukey test. Results: The initial data were compared with those after challenges using the Wilcoxon test (p<0.05). All composites showed a significant increase (p<0.05) of surface roughness, after overstress. Filtek Z350 XT and Renamel had the lowest final surface roughness values and roughness increase (p<0.05). The comparative analysis revealed that Estelite Σ Quick and Renamel did not significantly change the gloss after challenges (p=0.185). Filtek Z350 XT and IPS Empress Direct had higher color variations, after the challenges than the other resins (p<0.05). Conclusion: Chemical and mechanical challenges influence on characteristics of all composites, except for gloss on Estelite Σ Quick and Renamel composites (AU)

Physical characterization of multiparticulate systems

ABSTRACT The search for new pharmaceutical dosage forms and different drug delivery systems already used in therapeutics is a global trend, serving as an opportunity to expand the portfolio for the pharmaceutical industry. In this context, multiparticulate systems, such as pellets, granules, and minitablets, represent an attractive alternative, given the range of possibilities they provide. Among the methods used in the production of these systems, we highlight the process of extrusion-spheronization for pellet manufacture, wet granulation and hot-melt extrusion for the obtention of granules, and direct compression for minitablets. Although highly versatile, depending on the technology chosen, many processes and formulation variables can influence the ensuing stages of manufacture, as well as the final product. Therefore, the characterization of these small units is of fundamental importance for achieving batch homogeneity and optimal product performance. Analyses, including particle size distribution, morphology, density, porosity, mechanical strength and disintegration, are example tests used in this characterization. The objective of this review was to address the most widely used tests for the physical evaluation of multiparticulate systems.

Characterization of Mechanical Properties, Fluoride Release and Colour Stability of Dental Sealants

Objective: To compare the mechanical properties, fluoride release, colour stability and spreading characteristics of glass ionomer cement (GIC), compomer (CO), chemical (CR) and light-cured resin based (LR) fissure sealants. Material and Methods: Cylinders were prepared to determine mechanical properties by diametral tensile strength tests (stored for 24h in distilled water at 37°C) and fluoride release (24 hours, 3, 7 and 15 days; deionised water). Disk shaped specimens were prepared to determine colour stability (1 week in pigmenting solution; 37°C; CIE L*a*b*; ΔE). A simplified method of a spreading test was proposed to predict viscosity characteristics of the tested materials. Data were analysed using one-way ANOVA followed by T-test (p<0.05). Results: Results showed differences between materials regarding all tested properties. CO was statistically more resistant than the other materials (p<0.05), but no difference was observed between CR and LR. The fluoride release of GICs was significantly higher than the other materials (p<0.05). CO showed lower ΔE than the other materials in the following order: CO

Soft denture liners and sodium perborate: sorption, solubility and color change

Abstract Aim: To evaluate the sorption, solubility and color change in two lining materials after 120 days of immersion in either sodium perborate or artificial saliva. Methods: Thirty disk-shaped specimens (15×3 mm) of each material, Mucopren(r) soft (MS) and Elite(r) soft (ES) were manufactured and divided into two groups. The specimens in the control group (CG, n=15) were stored in artificial saliva at 37 °C. The specimens in the experimental group (EG, n=15) were stored in artificial saliva at 37 °C and immersed in sodium perborate daily for 5 min. The analysis of sorption and solubility was based on the initial dry weight and on the wet and dry weights after immersion. The color was assessed with a portable spectrophotometer and the NBS system. ANOVA and Tukey test (p<0.05) were used to analyze color and sorption. The solubility was analyzed by KruskalWallis test (p<0.05). Results: Sorption was higher in the EG group (0.31±0.08) than in the control group (0.26±0.05), and higher in Elite(r) soft relining (0.34±0.07) than in Mucopren(r) soft (0.23±0.06). There was no interaction between the factors. Elite(r) Soft presented a higher solubility when immersed in artificial saliva (CG: 0.16±0.07 and EG: 0.13±0.06; p=0.00). Mucopren(r) soft showed no solubility in either treatment. Regarding the color changes, there was a significant difference between the groups (CG: 9.2±1.2 and EG: 9.9±1.2; p=0.025) but not between the materials (Mucopren(r) soft: 9.4±1.3 and Elite(r)soft: 9.7±1.0; p=0.34). Using the NBS system, we verified that both materials presented a high color change. Conclusions: The daily use of sodium perborate promoted changes in the liners' sorption and color. Elite(r) soft relining was more prone to changes than Mucopren(r) soft.

Physical characterization of freeze-dried foam prepared from Aloe Vera gel and guar gum / Caracterización de espumas liofilizadas preparadas a partir de gel de Aloe vera y goma guar

Background: Foams are colloidal dispersions of a gas suspended in a dispersing phase, which consisting of a semi-freeze-dried or viscous liquid phase. The physical properties of food foams are the result of the bubble characteristics and their spatial arrangement. Objectives: The aim of this work was to obtain foams of A. vera gel and guar gum and describe the changes in their physical properties and microstructure during freeze-drying using the fractal dimension concept and image analysis techniques. Methods: The porosity, density, and volume expansion factor of the fresh foams that were based on the A. vera foams were determined. The kinetics of foam texture, color, porosity and microstructure of the freeze-dried foams were obtained. The fractal texture dimension of surface (FDSDBC) and microstructure (FDESEM) of the foams were determined as indicators of structural changes after freeze-drying. The guar gum concentrations used to obtain the A. vera prefoam were expressed in w/w as F1 (control sample without gum), F2 (2%), F3 (4%) and F4 (6%). Results: We obtained stable freeze-dried foams of Aloe vera gel and guar gum. The porosity, density and volume expansion factor of the fresh and freeze-dried foams were affected by the addition of the guar gum. Changes in the topology of the freeze-dried foam surface during the drying process resulted in a high rugosity compared with the original smooth surface. The microstructure of the dried foam samples suggested a relationship between the gum concentration of the prefoam A. vera gel mixture and the physical properties before and after freeze-drying, such as an increase in the microstructural alterations and surface roughness during freeze-drying. The roughness of the freeze-dried foam surface, described by the FDSDBC represented the macroscopic physical changes of the samples and correlated with the changes in the foam microstructure, which were described by the fractal dimension of the Environmental Scanning Electron Microscopy ESEM microphotographs (FDESEM). Conclusions: The digital analysis of the structure and porosity of the freeze-dried foam can be used to quantify the effect of gum concentrations on the morphological features and physical properties of foams during freeze-drying.

Antecedentes: Las espumas son dispersiones coloidales de un gas en una fase líquida viscosa. Las propiedades físicas de las espumas alimentarias son el resultado de las características de sus burbujas y su disposición espacial. Objetivos: El objetivo de este trabajo fue obtener espumas de gel de A. vera y goma guar y describir los cambios en sus propiedades físicas y su microestructura durante el secado por liofilización utilizando el concepto de dimensión fractal y las técnicas de análisis de imagen. Métodos: Se determinó la porosidad, densidad, factor de expansión volumétrico de las espumas frescas de A. vera. Así como la cinética de liofilización, textura, isotermas de sorción, color, porosidad y la microestructura las espumas liofilizadas. La dimensión fractal de la textura (FDSDBC) y microestructural (FDESEM) de las espumas de gel de A. vera y goma guar liofilizadas se determinó como un indicador de los cambios estructurales después de la liofilización. Las concentraciones de goma de guar utilizados para obtener la solución de clara de huevo preespuma se expresaron en w/w como F1 (muestra de control sin goma), F2 (2%), F3 (4%) y F4 (6%). Resultados: Fue posible obtener espumas liofilizadas estables de gel de A. vera y goma guar. La porosidad, densidad, factor de expansión volumétrico de las espumas se vieron afectadas con la adición de goma guar. Los cambios en la topología de la superficie de la espuma liofilizada durante todo el proceso de secado dieron lugar a alta rugosidad en comparación con la superficie lisa original. La microestructura de las muestras de espuma secas sugirió una relación entre la concentración de goma de las espumas de A. vera y las propiedades físicas antes y después de la liofilización como un aumento en las alteraciones microestructurales y rugosidad de la superficie durante el secado por congelación. La rugosidad de la superficie de la espuma liofilizada, se describió por la relación FDSDBC que representa los cambios físicos macroscópicos de las muestras y se correlacionó con los cambios en la microestructura de espuma, que fueron descritos por la dimensión fractal de las micrografías ESEM (FDESEM). Conclusiones: El análisis digital de la estructura y la porosidad de la espuma liofilizada se puede utilizar para cuantificar el efecto de las concentraciones de goma guar en las características morfológicas de las espumas durante el secado por congelación.

Radiant exposure effects on physical properties of methacrylate - and silorane-composites

AIM: To evaluate the effect of different radiant exposures on the degree of conversion (DC), Knoop hardness number (KHN), plasticization (P), water sorption (WS), and solubility (S) of different monomer resin-based composites. METHODS: Circular specimens (5 x 2 mm) were manufactured from methacrylate and silorane composite resins, and light-cured at 19.8, 27.8, 39.6, and 55.6 J/cm2, using second-generation LED at 1,390 mW/cm2. After 24 h, DC was obtained using a FT-Raman spectrometer equipped with a Nd:YAG laser, KHN was measured with 50-g load for 15 s, and P was evaluated on the top and bottom surfaces by the percentage of hardness reduction after 24 h immersed in absolute alcohol. WS and S were determined according to ISO 4049. Data were subjected to statistical analysis (α=0.05). RESULTS: Methacrylate material presented higher DC, KHN, P, and WS than silorane (p<0.05). There was no difference in the S values (p>0.05). The increased radiant exposures improved only the KHN (p<0.05). In general, top surfaces showed higher DC and KHN than bottom, for both materials (p<0.05). The increase of the radiant exposure did not improve most physical properties of the composites and were monomer-base dependent. CONCLUSIONS: Chemical composition of the composite resins resulted in different physical properties behavior and could affect the clinical longevity of dental restorations, but overall these properties were not influenced by the different radiant exposures evaluated in the study...