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1.
Braz. j. biol ; 81(1): 1-10, Feb. 2021. tab, graf
Article in English | LILACS | ID: biblio-1153324

ABSTRACT

Abstract Starch samples from eight legumes cultivars instar of one variety of Vigna unguiculata L. (Cowpea), one variety of Vigna subterrenea V. (Bambara groundnut) and six varieties of Phaseolus vulgaris L. (Common bean), grown in Cameroon were isolated, and their physicochemical and pasting properties were evaluated. The objectives of the study were to investigate the starch properties and processing characteristics of different bean varieties, and to establish the basic foundation of improving the functionality of beans and their starch grown in the region. The result revealed significant differences amongst the properties of the starches. The swelling power of the legume starch isolates put them in the category of highly restricted-swelling starch. This characteristic is desirable for the manufacture of value-added products such as noodles and composite blends with cereals. The pasting properties were determined using a rapid visco analyzer, and various legumes bean starches exhibited different pasting profiles. The high breakdown viscosity (BV) was founded for Cowpea and Bambara groundnut and confirmed their low. ability to resist heat and shear stress when compared to Common bean varieties studies. The factors which influence the pasting characteristics resulting to decrease in peak viscosity (PV), trough viscosity (TV) and final viscosity (FV) of starch are attributed to the interaction of starch with the protein, fat, etc. which depended to their variety.


Resumo Foram isoladas amostras de amido de oito cultivares de leguminosas ínstar de uma variedade de Vigna unguiculata L. (feijão caupi), uma variedade de Vigna subterrenea V. (amendoim Bambara) e seis variedades de Phaseolus vulgaris L. (feijão comum), cultivadas nos Camarões, e suas propriedades físico-químicas e de pasta foram avaliadas. Os objetivos do estudo foram investigar as propriedades do amido e as características de processamento de diferentes variedades de feijão e estabelecer as bases básicas para melhorar a funcionalidade do feijão e do amido cultivado na região. O resultado revelou diferenças significativas entre as propriedades dos amidos. O poder de inchamento dos isolados de amido de leguminosas os coloca na categoria de amido com inchamento altamente restrito. Esta característica é desejável para o fabrico de produtos de valor acrescentado, tais como macarrão e misturas compósitas com cereais. As propriedades de pasta foram determinadas usando um analisador rápido de visco, e vários amidos de feijão leguminosos exibiram diferentes perfis de pasta. A alta BV foi fundada para o amendoim Cowpea e Bambara e confirmou sua baixa. capacidade de resistir ao calor e tensão de cisalhamento quando comparado com estudos de variedades de feijão. Os fatores que influenciam as características colantes resultantes da diminuição do pico de viscosidade (PV), da viscosidade mínima (TV) e da viscosidade final (FV) do amido são atribuídos à interação do amido com a proteína, gordura, etc., que dependem da sua variedade.


Subject(s)
Amylose , Fabaceae , Starch , Viscosity , Cameroon
2.
Article in Chinese | WPRIM | ID: wpr-888098

ABSTRACT

To explore the correlation between concentrate viscosity and molding quality of personalized traditional Chinese medicine(TCM) condensed water pill, this study established a concentrate viscosity characterization method with rotational rheometry. Seven model prescriptions were respectively concentrated to different degrees and the viscosity of each concentrate was determined. The pre-sence of 'viscosity jump' in the middle stage of 'flag hanging' of all the model prescriptions implied that there might be an ideal viscosity range in the preparation of condensed water pill. The further study of 22 model prescriptions demonstrated that the optimum viscosity range of concentrate was 5-15 Pa·s(25 ℃) for approximately 82% of the prescriptions. About 18% of the prescriptions had a wide range, which might be caused by the high proportions of mineral and crustacean drugs in the crushing part and sugar and fibrous drugs in the decocting part. This study clarified the optimum viscosity range for concentrates of personalized TCM condensed water pills and achieved a preparation technology without any excipient, laying a foundation for the on-line control of the preparation.


Subject(s)
Drugs, Chinese Herbal , Excipients , Medicine, Chinese Traditional , Viscosity , Water
3.
Article in English | LILACS, BBO | ID: biblio-1143393

ABSTRACT

ABSTRACT Objective: To evaluate the amount of residual monomers released after polymerization by the compomers in different colors and viscosities over time. Material and Methods: The compomer samples of different colors and viscosities (flowable compomers; blue-pink and packable compomers; A2-blue-pink-gold) were prepared in molds with an inner diameter of 5 mm and a height of 2 mm. In polymerization of samples, a LED unit was used. The amount of monomers released from the samples kept in 75% ethanol/water solution was measured by a high-performance liquid chromatography (HPLC) instrument in the 10th minute, in the 1st hour, and in the 1st, 7th, and 14th days. For statistical analyses, the paired sample t-test, independent sample t-test, and one-way ANOVA with Tukey's post hoc test were used. Results: The amount of residual monomers released from all materials increased over time. At the end of the 14th day, the most released monomer from all compomer samples was BisGMA. The total amounts of released monomers from the packable compomers were Gold>A2>blue>pink. The amount of residual monomers released from flowable compomers was higher in blue than in pink. Conclusion: The color and the viscosity are the factors affecting the residual monomer release in compomers.


Subject(s)
Chromatography/instrumentation , Compomers , Dental Materials , Polymerization , Turkey/epidemiology , Viscosity , Analysis of Variance , Chromatography, High Pressure Liquid/instrumentation , Statistics, Nonparametric
4.
Revista Areté ; 21(1): 33-41, 2021. ilus, tab
Article in Spanish | LILACS, COLNAL | ID: biblio-1354622

ABSTRACT

La iniciativa internacional para la estandarización de la dieta de disfagia (IDDSI) clasifica la viscosidad de los líquidos por niveles y determina metodologías específicas para evaluar cada consistencia. Con todo, la iniciativa no determina las medidas específicas de espesante requeridas para obtener cada nivel de viscosidad y sugiere hacer adaptaciones de acuerdo con las condiciones particulares de aplicación. Este estudio desarrolló una propuesta para la preparación de viscosidades mediante pruebas experimentales en las que se controló rigurosamente la cantidad de espesante y agua haciendo uso de instrumentos de mezclado de fácil acceso en entornos clínicos (vasos plásticos, jarra de agua, baja lenguas para integrar los elementos y cronómetro para considerar el tiempo de fraguado). Posterior a ello, cada nivel de viscosidad obtenido fue evaluado con el test de flujo propuesto por las IDDSI. Como resultado, este estudio especifica las cantidades necesarias de agua y espesante para conseguir viscosidad en bebidas de 0-4. Los hallazgos presentados, tienen en cuenta factores influyentes como la ubicación geográfica, temperatura y altitud. Se espera que esta propuesta incida en las dinámicas de evaluación de la deglución en el área clínica colombiana de forma que esta sea más precisa y eficaz. Finalmente, es pertinente realizar futuras investigaciones que determinen medidas específicas de espesante para lograr cambios en la viscosidad de líquidos diferentes al agua e igualmente necesario, replicar esta propuesta con otros espesantes de más fácil acceso para los usuarios y que tengan en cuenta otros aspectos como la palatabilidad


The International Dysphagia Diet Standardisation Initiative (IDDSI) classifies the viscosity of liquids by levels and determines specific methods to evaluate each consistency. However, the initiative does not determine the specific measures of thickener required to obtain each level of viscosity and suggests making adaptations according to the particular conditions of application. This study developed a proposal for the preparation of viscosities through experimental tests in which the amount of thickener and water was rigorously controlled using mixing instruments that were easily accessible in clinical settings (plastic cups, pitcher of water, tongue depressors to integrate the elements and timer to consider setting time). After that, each level of viscosity obtained was evaluated with the flow test proposed by the IDDSI. As a result, this study specifies the required amounts of water and thickener to achieve drinks viscosities 0-4. The findings presented take into account influencing factors such as geographic location, temperature and altitude. It is expected that this proposal will affect the dynamics of swallowing assessment in the Colombian clinical area so that it is more precise and effective. Finally, it is pertinent to carry out future investigations that determine specific measures of thickener to achieve changes in the viscosity of liquids other than water and it is equally necessary to replicate this proposal with other thickeners that are easier for users to access and that take into account other aspects such as palatability.


Subject(s)
Tongue , Deglutition Disorders , Deglutition , Reference Standards , Viscosity , Volition , Beverages , Water , Preparedness , Diet , Thickeners
5.
J. appl. oral sci ; 29: e20200609, 2021. tab, graf
Article in English | LILACS | ID: biblio-1154615

ABSTRACT

Abstract Objective To compare the effectiveness of ART restorations using High Viscosity Glass-ionomer cement (HVGIC) with conventional restorations using resin composite in Class II cavities of permanent teeth, in a 2-year follow-up. Methodology Seventy-seven restorations were made with each restorative material, Equia Fil-GC Corporation (ART restorations) and Z350-3M (conventional restoration), in 54 participants in this parallel and randomized clinical trial. Restorations were evaluated at 6 months, 1 and 2 years using the ART and the modified United States Public Health Service (USPHS) criteria. Chi-square test and Survival Analysis (p<0.05) were used for statistical analysis. Results The success rates for ART restorations were 98.7% (6 months) and 95.8% (1 year) for both criteria. At 2 years, success rate was 92% and 90.3% when scored by the modified USPHS and ART criteria (p=0.466), respectively. The success rates for conventional restorations were 100% (6 months), 98.7% (1 year) and 91.5% (2 years) for both assessment criteria. ART restorations presented a lower survival rate by the criterion of ART (83.7%) when compared to the modified USPHS criterion of (87.8%), after 2 years (p=0.051). The survival of conventional restorations was 90.7% for both evaluation criteria. Conclusion At the 2-years follow-up evaluation, no statistically significant difference was observed between the success rate of ART restorations with HVGIC compared to conventional restorations with resin composite in Class II cavities of permanent teeth.


Subject(s)
Humans , Dental Caries , Glass Ionomer Cements , Viscosity , Prospective Studies , Follow-Up Studies , Composite Resins , Dental Restoration, Permanent
6.
Article in English | LILACS, BBO | ID: biblio-1143394

ABSTRACT

ABSTRACT Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.


Subject(s)
Humans , Male , Female , Child , Saliva/microbiology , Biofilms , Viridans Streptococci , Histatins , Hydrogen-Ion Concentration , Spectrophotometry/instrumentation , Streptococcus mutans , Viscosity , Analysis of Variance , Statistics, Nonparametric , Indonesia/epidemiology
7.
J. oral res. (Impresa) ; 9(2): 98-103, abr. 30, 2020. ilus, graf, tab
Article in English | LILACS | ID: biblio-1151857

ABSTRACT

Evaluate the effect of a synbiotic on salivary viscosity and buffer capacity. Materials and Methods: A follow-up one-week study was performed on 24 healthy volunteers in San Luis Potosí, Mexico, during July 2017. Volunteers must have had active tooth decay at the moment of study. All 24 patients were given a Lactiv® probiotic package, advising not to modify usual oral hygiene practices, and were followed up during 6 days. Primary output variable was salivary viscosity while the secondary was salivary buffer capacity. Salivary viscosity was assessed by using an Ostwald Pipette and buffer capacity with bromocresol purple. Results: A total of 8 male patients (33.3%) and 16 females (66.6%) patients were included, with an average age of 10.92 years. All the volunteers completed the study. Comparisons between pre- and post-treatment showed a decrease in salivary viscosity, while buffer capacity was showed to increase. Conclusion: The use of a synbiotic during a short period of time lowered the viscosity of saliva and increased salivary buffer capacity.


Evaluar el efecto de un sinbiótico sobre la viscosidad salival y la capacidad de tampón de la saliva. Materiales and Métodos: Se realizó un estudio de seguimiento de una semana en 24 voluntarios sanos en San Luis Potosí, México, durante julio de 2017. Los voluntarios cursaban caries dental activa en el momento del estudio. Los 24 pacientes recibieron un paquete de probióticos Lactiv®, fueron aconsejados a no modificar las prácticas habituales de higiene oral, y fueron seguidos durante 6 días. La variable primaria fue la viscosidad salival mientras que la secundaria fue la capacidad tampón. La viscosidad salival se evaluó usando una pipeta Ostwald y capacidad tampón con bromocresol púrpura. Resultados: Se incluyeron un total de 8 pacientes varones (33,3%) y 16 mujeres (66,6%), con una edad promedio de 10,92 años. Todos los voluntarios completaron el estudio. Las comparaciones entre el pretratamiento y el postratamiento mostraron una disminución de la viscosidad salival, mientras que se demostró que la capacidad del tampón aumentó. Conclusión: El uso de un sinbiótico durante un corto período de tiempo mostró un efecto sobre la disminución de la viscosidad y el aumento de la capacidad del tampón salival.


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Adolescent , Saliva/drug effects , Probiotics/administration & dosage , Synbiotics , Viscosity , Treatment Outcome , Dental Caries , Non-Randomized Controlled Trials as Topic , Mexico
8.
Article in Chinese | WPRIM | ID: wpr-879212

ABSTRACT

A high throughput measurement method of human red blood cells (RBCs) deformability combined with optical tweezers technology and the microfluidic chip was proposed to accurately characterize the deformability of RBCs statistically. Firstly, the effective stretching deformation of RBCs was realized by the interaction of photo-trapping force and fluid viscous resistance. Secondly, the characteristic parameters before and after the deformation of the single cell were extracted through the image processing method to obtain the deformation index of area and circumference. Finally, statistical analysis was performed, and the average deformation index parameters (


Subject(s)
Erythrocyte Deformability , Erythrocytes , Humans , Microfluidics , Optical Tweezers , Viscosity
9.
Chinese Journal of Biotechnology ; (12): 2260-2276, 2020.
Article in Chinese | WPRIM | ID: wpr-878484

ABSTRACT

Dissolving pulp consists of high purity cellulose and is widely used to as raw materials for the production of regenerated cellulose fiber, cellulose ester and cellulose ether. The characteristic of dissolving pulp affects greatly the production and processing performance of subsequent products. The α-cellulose content, hemicellulose content, pulp viscosity, ash, transition metal ion content, fiber morphology, molecular weight distribution of cellulose and the reactivity are the important properties. Because of its green, mild and high efficiency, the application of enzymes in improving the properties of dissolving pulp has a promising application prospect and has been researched significantly. In this review, the main properties of dissolving pulp are presented first, followed by a recommendation of the enzymes to improve these properties. The application and current research of cellulase and xylanase in improving the properties of dissolving pulp are emphasized. The main problems and the future research areas in improving the properties of dissolving pulp by enzymes are revealed. Finally, the technology prospects in this field are proposed.


Subject(s)
Cellulase , Molecular Weight , Viscosity , Wood
11.
Braz. oral res. (Online) ; 34: e099, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132660

ABSTRACT

Abstract The composition of infiltrants can influence their physical properties, viscosity and depth of penetration (DP). Strategies are used to increase the DP, such as the addition of diluents or the use of heat. This study aimed to evaluate the effect of preheating and composition on physical properties and DP of infiltrants in demineralized enamel. The groups were assigned, and the following experimental formulations were made: 25%BisEMA +75%TEGDMA; 25%BisEMA +65%TEGDMA +10%ethanol; 25%BisEMA +65%TEGDMA +10%HEMA; 100%TEGDMA; 90%TEGDMA +10%ethanol; 90%TEGDMA +10%HEMA. The samples were photoactivated at two temperatures (25°C and 55°C). Degree of conversion (DC) was performed using an infrared spectrophotometer. Elastic modulus (E), flexural strength (FS) and contact angle (CA) tests were also performed. The DP of an infiltrant in demineralized enamel was determined by confocal laser scanning microscopy (CLSM) using an indirect labeling technique. The data were analyzed by two-way ANOVA and Tukey's test. DC increased after preheating in all the groups; however, 90%TEGDMA+10%ethanol showed the lowest DC for both temperatures, and the lowest E. Preheating did not influence E or FS. The CA increased at 55°C for most groups, but decreased for groups containing HEMA. Temperature did not seem to influence DP, and Icon showed the lowest DP values. The 100%TEGDMA composition showed more homogeneous penetration, whereas Icon showed heterogeneous and superficial penetration. The preheating technique does not improve all properties in all the material compositions. The composition of a material can influence and improve its properties.


Subject(s)
Dental Enamel , Polyethylene Glycols , Polymethacrylic Acids , Viscosity , Materials Testing , Bisphenol A-Glycidyl Methacrylate , Composite Resins , Elastic Modulus , Methacrylates
12.
Niger. J. Dent. Res ; 5(2): 131-135, 2020. ilus
Article in English | AIM, AIM | ID: biblio-1266997

ABSTRACT

Objective: To determine relative saliva viscosity (RSV) among carious and non-carious young adult Nigerians. Methods: Participants included in this study were young adults of both sexes aged 11-40 years recruited and categorized as non-carious individuals as those with Decayed, Missing and Filled Teeth (DMFT) of 0 and carious individual as those with DMFT of ≥1. The collection of unstimulated saliva samples was done using disposable cups and aspirated into 10 mls syringe. RSV was determined by allowing saliva to flow through a 10 mls syringe and measuring the rate of flow from 2 mls to 0 mls. The timing was done by means of a stopwatch and recorded in seconds. The plunger of the disposable syringe is carefully removed to allow the saliva to flow through the adaptor without the needle. The start off for the flow is usually above 2 mls but timing start off timing is at 2 mls as a precautionary measure. This is a simple and accurate model for measuring the viscousity of liquid (Figure 1). Statistical tests used in this study were independent t-test and one-way ANOVA. Statistical significance was at P <0.05. Results: The participants in this study were between 17 and 40 years with a mean age of 27.81±6.56 years. The overall mean relative saliva viscosity among the participants was 1.93±0.26. The mean relative saliva viscosity was 2.39±0.65 among participants aged 31-40years old. Female participants had mean relative saliva viscosity of 2.09±0.40. Participants with dental caries had mean relative saliva viscosity of 2.41±0.44. Conclusion: Relative saliva viscosity measured with a 10 disposable syringe was found to be higher in participants with dental caries than those without. Strategies to prevent dental caries should include efforts to increase the viscosity of saliva. Salivary viscosity of 1.16-1.66 P oise (P) (which is the CGS unit of viscosity) signifies oral cavity without dental caries. The SI Unit of viscosity is pascal second (Pa s). Ten poise equal one pascal second making the centipoise (cP) and millipascal second (mPa s) identical. Further studies on salivary viscosity and severity of dental caries is recommended


Subject(s)
Dental Caries , Nigeria , Salivary Glands , Viscosity , Young Adult
13.
Braz. J. Pharm. Sci. (Online) ; 56: e17509, 2020. tab, graf
Article in English | LILACS | ID: biblio-1132046

ABSTRACT

Amphotericin B is a broad spectrum antifungal agent used to treat fungal infections. Organogel is a semisolid preparation in which the apolar phase gets immobilized within spaces of the three-dimensional structure. The current study aimed at the formulation and comparative evaluation of sorbitan monostearate organogels and pluronic lecithin organogels (PLO). Different compositions of span 60 based organogels were prepared by varying the concentrations of the span 60 and PLO gels were prepared by varying the concentration of Pluronic F 127. The developed organogels were subjected to various characteristics such as pH, viscosity, spreadability, extrudability, and drug release studies. The optimized formulations were evaluated against Candida albicans and carried out ex vivo release study. The optimized formulation was selected from span 60 based organogels, and pluronic lecithin organogels were S1 and P1, respectively. The optimized formulation (S1) showed effective inhibition against Candida albicans. The skin irritation test was carried out on albino mice for optimized formulations and results showed that no irritation to the skin. Based on the results, organogels prepared by sorbitan monostearate showed better antifungal activity, and also all the formulations were found to be stable and safe throughout the study period.


Subject(s)
Skin , Candida albicans/classification , Amphotericin B/agonists , Growth and Development , Antifungal Agents/analysis , Viscosity , Drug Liberation , Mycoses/pathology
14.
Braz. dent. j ; 30(6): 592-598, Nov.-Dec. 2019. tab, graf
Article in English | LILACS | ID: biblio-1055449

ABSTRACT

Abstract This study aimed to evaluate the polymerization properties of bulk-fill materials (low and high-viscosity) by using high-intensity continuous light and intermittent photo-activation in terms of polymerization shrinkage stress and degree of conversion (DC). The following Bulk-fill and Conventional nanofilled resin composites were evaluated: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) and Filtek Bulk Fill Posterior (3M/ESPE). A LED device (DB 685, Dabi Atlante) was used for both protocols: continuous uniform and intermittent photo-activation (light-on and light-off cycles) with identical radiant exposure (14 J/cm2). The polymerization shrinkage stress (n=6) was evaluated by inserting a single increment of 12 mm3 between two stainless steel plates (6×2 mm) adapted to a Universal Testing Machine (UTM), at different times. Measurements were recorded after photo-activation. The degree of conversion was evaluated by Fourier transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory (n=5). Data were analyzed by three-way ANOVA and Tukey's HSD (α=0.05) tests. Bulk Fill Posterior presented higher shrinkage stress values when photo-activated with the intermittent technique (p<0.05). The intermittent photo-activation increased the degree of conversion for the low-viscosity bulk-fills (p<0.05). Therefore, the use of modulated photo-activation (intermittent) must be indicated with caution since its use can influence the shrinkage stress and degree of conversion of composites, which varies according to the resin formulations.


Resumo O presente estudo teve como objetivo avaliar as propriedades de polimerização de materiais bulk-fill (baixa e alta viscosidade) utilizando luz contínua de alta intensidade e fotoativação intermitente em relação ao estresse de contração de polimerização e grau de conversão (DC). As seguintes resinas compostas Bulk-fill e nanohíbridas convencionais foram avaliadas: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) e Filtek Bulk Fill Posterior (3M/ESPE). Um dispositivo de LED (DB 685, Dabi Atlante) foi utilizado nos dois protocolos: fotoativação contínua e intermitente contínua (ciclos de liga e desliga) com exposição idêntica (14 J/cm2). A tensão de contração de polimerização (n=6) foi avaliada através da inserção de um incremento único de 12 mm3 entre duas placas de aço inoxidável (6×2 mm) adaptadas a uma Máquina de Ensaio Universal (UTM), em tempos diferentes. As medições foram registradas após a fotoativação. O grau de conversão foi avaliado por FTIR-ATR (n=5). Os dados foram analisados ​​pelos testes ANOVA a três fatores e teste de Tukey (α=0,05). A resina Bulk Fill Posterior apresentou maiores valores de tensão de contração quando fotoativadas com a técnica intermitente (p<0,05). A fotoativação intermitente aumentou o grau de conversão nas resinas bulk-fill de baixa viscosidade (p<0,05). Portanto, o uso de fotoativação modulada (intermitente) deve ser indicado com cautela, uma vez que seu uso pode influenciar a tensão de contração e o grau de conversão dos compósitos, o que varia de acordo com as formulações da resina.


Subject(s)
Materials Testing , Composite Resins , Viscosity , Polymerization
15.
Braz. dent. j ; 30(5): 476-483, Sept.-Oct. 2019. tab, graf
Article in English | LILACS | ID: biblio-1039146

ABSTRACT

Abstract The aim of this study was to evaluate the bond strength, bottom/top hardness ratio, marginal adaptation, and interfacial nanoleakage of regular viscosity bulk fill composites (RVBFC) and regular viscosity traditional composites (RVTC). Two RVBFC (Filtek Bulk Fill and Aura Bulk Fill) and two RVTC (Filtek Z250XT and Aura) were assessed. Forty conical cavities (4.8×2.8×4.0) were prepared in bovine dentin and restored with composites (n=10). After 24h in water, marginal adaptation was evaluated by staining with a caries detector. The top and bottom surfaces of the conical restorations were stained for five seconds and the gap percentage in the composite/dentin interface was determined using digital images on a measurement program (ImageTool). The Vickers microhardness was measured and the bottom/top microhardness ratio (B/T) was determined. Push-out bond strength test was performed in a universal testing machine (0.5mm/min) and failure modes were evaluated in a stereomicroscope (20×). Other specimens (n=3) were produced for interfacial nanoleakage evaluation. Data were analyzed using one and two-way ANOVA and Tukey's test (α=0.05). The gap percentage was higher in the bottom compared to the top. The B/T ratio of the Aura Bulk Fill was statistically lower than other composites. Push-out bond strength were similar among composites. The RVBFC presented lower nanoleakage than the RVTC in the bottom of the conical restoration and there was no difference among the materials in the top surfaces. In conclusion, Filtek Bulk Fill performed better than Aura Bulk Fill regarding the analyzed properties.


Resumo O objetivo deste estudo foi avaliar a resistência de união, razão base/topo de microdureza, adaptação marginal e nanoinfiltração interfacial de resinas compostas bulk fill (BF) e tradicional (RT) de viscosidade regular.: Duas BF (Filtek Bulk Fill e Aura Bulk Fill) e duas RT (Filtek Z250XT e Aura) foram testados. Quarenta cavidades cônicas (4,8×2,8×4,0) foram preparadas em dentina bovina e restauradas com os compósitos (n=10). Depois de 24 h em água, a adaptação marginal foi avaliada por meio do corante com detector de cárie. As faces de topo e base das restaurações cônicas foram coradas por cinco segundos e a porcentagem de fendas na interface compósito/dentina foi determinada utilizando-se imagens analisadas num programa (ImageTool). A microdureza Vickers foi mensurada e a razção base/topo de microdureza (B/T) foi determinada. A resistência de união por push-out foi executada numa máquina de ensaios universal (0,5mm/min) e o padrão de fratura avaliado num estereomicroscópio (20x). Espécimes adicionais (n=3) foram confeccionados para avaliação da nanoinfiltração interfacial. Os dados foram analisados por meio de ANOVA a dois fatores e teste de Tukey (a=0,05). A porcentagem de fendas foi maior na base que no topo. A B/T da Aura Bulk Fill foi estatisticamente menor que os demais compósitos. A resistência de união por push-out foi similar entre os compósitos. As BF apresentaram menos nanoinfiltração que as RT na base das restaurações cônicas e não houve diferenças entre os materiais no topo. Conclui-se que a Filtek Bulk Fill comportou-se melhor que a Aura Bulk Fill considerando-se as propriedades analisadas.


Subject(s)
Animals , Composite Resins , Dental Caries , Viscosity , Materials Testing , Cattle , Dentin , Hardness
16.
ARS med. (Santiago, En línea) ; 44(1): 46-50, 2019. ilus
Article in Spanish | LILACS | ID: biblio-1046760

ABSTRACT

Introducción: la Macroglobulinemia de Waldenström (MW) es un tipo raro de linfoma de células B caracterizado por la proliferación de células linfoplasmocíticas que secretan altas cantidades de inmunoglobulinas M (IgM) monoclonales. Puede presentarse con una amplia gama de síntomas, entre ellos los derivados del aumento de la viscosidad plasmática. Métodos: reportamos un caso de MW que presentó una trombosis de la vena central de la retina (TVCR) bilateral en el contexto de un síndrome de hiperviscosidad (SHV). El objetivo de este trabajo fue revisar algunos aspectos clínicos de la MW, con especial énfasis en el SHV y la TVCR. Resultados: las manifestaciones clínicas y de laboratorio de la MW son inespecíficas y comunes a otras neoplasias hematológicas. El SHV se produce cuando los niveles de IgM sobrepasan los 3 mg/dL, situación que ocurre en un 15-30 por ciento de los pacientes. La TVCR es una complicación grave y rara asociada al SHV, presentándose típicamente como una pérdida de agudeza visual indolora. El fondo de ojo exhibe signos característicos, como tortuosidad venosa y hemorragias retinales hasta la periferia, y la angiografía con fluorosceína y la OCT pueden orientar al diagnóstico y guiar el manejo. El tratamiento incluye la plasmaféresis y tratamientos oftalmológicos basados en agentes antioangiogénicos. Conclusión: la MW es una enfermedad incurable. Sin embargo, es importante sospechar una TVCR en pacientes que debutan con una pérdida de agudeza visual, ya que existen tratamientos efectivos en el manejo de esta complicación. (AU)


Introduction: Waldenstrom's Macroglobulinemia (WM) is a rare type of B-cell lymphoma characterized by proliferation of lymphoplasmocitarian cells that secrete high amounts of monoclonal immunoglobulin M (IgM). It may present with a wide range of symptoms, including the ones that derivatives of the increase in plasma viscosity. Methods: we report a case of WM that presented a bilateral central retinal vein occlusion (CRVO) in the context of a hyperviscosity syndrome (HVS). The objective of this study was to review clinical aspects of the WM, with special emphasis on the HVS and the CRVO. Results: the WM laboratory and clinical manifestations are common to other hematological malignancies. The HVS occurs when levels of IgM exceed 3 mg/dL, situation that occurs in 15-30 percent of patients. The CRVO is a serious and rare complication associated with the HVS, typically presented as a painless visual acuity loss. The fundoscopic examination exhibits characteristic signs, such as venous tortuousity and retinal hemorrhages in all four quadrants and most numerous in the periphery; angiography with fluoroscein and the OCT can orientate the diagnosis and guide the management. The treatment includes plasmapheresis and other ophthlamological treatments based on antiangiogenic agents. Conclusion: the WM is an incurable disease. However, it is important to suspect a CRVO in patients who made their debut with a loss of visual acuity, since there are effective treatments in the management of this complication.(AU)


Subject(s)
Humans , Retinal Vein Occlusion , Waldenstrom Macroglobulinemia , Therapeutics , Viscosity
17.
Braz. oral res. (Online) ; 33: e125, 2019. tab, graf
Article in English | LILACS, BBO | ID: biblio-1100928

ABSTRACT

Abstract Atraumatic Restorative Treatment (ART) is one of the strategies used to control dental caries; it involves hand instruments for removal of carious tissue, and restorations using high-viscosity Glass Ionomer Cement (GIC). The present controlled clinical trial aimed to evaluate the performance of low-cost GIC indicated for ART in primary teeth, compared with high-viscosity GIC, after one year of follow-up. Two-to six-year-old children with dentin caries lesions on one or two surfaces of anterior and posterior teeth were selected. The children were randomly assigned to 2 groups according to the restorative material used: G1 (control) - Ketac Molar®; G2 (experimental) - Vitro Molar®. Treatments were performed in a school setting, following the guidelines of the ART. A total of 728 restorations were performed in 243 children. Descriptive analysis and Poisson regression were applied, with a significance level of p < 0.05. After 12 months, 559 (76.8%) restorations were re-evaluated. The success rate was evaluated by the prevalence ratio (PR), associated with restorations performed in primary second molars (PR = 1.21; 95%CI = 1.03-1.42), and with small (PR = 1.35; 95%CI = 1.14-1.60) or medium cavities (PR = 1.29; 95%CI = 1.08-1.55), using Ketac Molar® material (PR= 1.07; 95%CI = 1.01-1.15), considering p < 0.05. Small or medium restorations in primary second molars performed with high-viscosity GIC (Ketac Molar®) were more successful than restorations performed with low-cost GIC indicated for ART.


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Dental Caries/therapy , Dental Atraumatic Restorative Treatment/methods , Glass Ionomer Cements/chemistry , Time Factors , Tooth, Deciduous , Viscosity , Materials Testing , Poisson Distribution , DMF Index , Treatment Outcome , Dental Restoration Failure , Dental Restoration, Permanent/methods , Glass Ionomer Cements/therapeutic use
18.
Article in English | WPRIM | ID: wpr-788764

ABSTRACT

OBJECTIVE: The objective of this study was to analyze patient-specific blood flow in ruptured aneurysms using obtained non-Newtonian viscosity and to observe associated hemodynamic features and morphological effects.METHODS: Five patients with acute subarachnoid hemorrhage caused by ruptured posterior communicating artery aneurysms were included in the study. Patients’ blood samples were measured immediately after enrollment. Computational fluid dynamics (CFD) was conducted to evaluate viscosity distributions and wall shear stress (WSS) distributions using a patient-specific geometric model and shear-thinning viscosity properties.RESULTS: Substantial viscosity change was found at the dome of the aneurysms studied when applying non-Newtonian blood viscosity measured at peak-systole and end-diastole. The maximal WSS of the non-Newtonian model on an aneurysm at peaksystole was approximately 16% lower compared to Newtonian fluid, and most of the hemodynamic features of Newtonian flow at the aneurysms were higher, except for minimal WSS value. However, the differences between the Newtonian and non-Newtonian flow were not statistically significant. Rupture point of an aneurysm showed low WSS regardless of Newtonian or non-Newtonian CFD analyses.CONCLUSION: By using measured non-Newtonian viscosity and geometry on patient-specific CFD analysis, morphologic differences in hemodynamic features, such as changes in whole blood viscosity and WSS, were observed. Therefore, measured non-Newtonian viscosity might be possibly useful to obtain patient-specific hemodynamic and morphologic result.


Subject(s)
Aneurysm , Aneurysm, Ruptured , Blood Viscosity , Hemodynamics , Humans , Hydrodynamics , Intracranial Aneurysm , Rupture , Subarachnoid Hemorrhage , Viscosity
19.
Article in Korean | WPRIM | ID: wpr-787360

ABSTRACT

The aim of this study was to compare the degree of conversion and polymerization shrinkage of low and high viscosity bulk-fill giomer-based and resin-based composites. Two bulk-fill giomer (Beautifil Bulk Restorative (BBR), Beautifil Bulk Flowable (BBF)), two bulk-fill (Tetric N-Ceram Bulk-fill (TBF), SureFil SDR flow (SDR)) and two conventional resin composites (Tetric N-Ceram (TN), Tetric N-flow (TF)) were selected for this study. The degree of conversion was measured by using Fourier transform infrared spectroscopy. Polymerization shrinkage was measured with the linometer. For all depth, BBR had the lowest degree of conversion and SDR had the highest. At 4 mm, the degree of conversion of low and high viscosity bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). At the depth between 2 mm and 4 mm, there were significant difference with TBF, TN and TF (p < 0.05), while no significant difference in the degree of conversion was measured for BBR, BBF and SDR. Polymerization shrinkage of six resin composites decreased in the following order: TF > SDR > BBF > TBF > TN and BBR (p < 0.05). Polymerization shrinkage of bulk-fill giomer resin composites was lower than that of bulk-fill resin composites (p < 0.05). From this study, it is found that the bulk-fill giomer resin composites and TBF were not sufficiently cured in 4 mm depth. The degree of conversion of low and high viscosity bulk-fill giomer resin composites was significantly lower than bulk-fill resin composites in both 2 mm and 4 mm depths. Therefore, such features of bulk-fill giomer resin composites should be carefully considered in clinical application.


Subject(s)
Polymerization , Polymers , Spectroscopy, Fourier Transform Infrared , Viscosity
20.
Article in Chinese | WPRIM | ID: wpr-774164

ABSTRACT

Study of the mechanical properties of in vivo corneal materials is an important basis for further study of corneal physiological and pathological phenomena by means of finite element method. In this paper, the elastic coefficient ( ) and viscous coefficient ( ) of normal cornea and keratoconus under pulse pressure are calculated by using standard linear solid model with the data provided by corneal visualization scheimpflug technology. The results showed that there was a significant difference of and between normal cornea and keratoconus cornea ( < 0.05). Receiver operating characteristic curve analysis showed that the area under curve (AUC) for , and their combined indicators were 0.776, 0.895 and 0.948, respectively, which indicated that keratoconus could be predicted by and . The results of this study may provide a reference for the early diagnosis of keratoconus and avoid the occurrence of keratoconus after operation, so it has a certain clinical value.


Subject(s)
Area Under Curve , Cornea , Physiology , Elasticity , Humans , Keratoconus , Pathology , ROC Curve , Viscosity
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