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1.
Rev. ADM ; 78(2): 73-79, mar.-abr. 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1247336

ABSTRACT

El color es un efecto visual de los rayos de luz reflejándose y su concepto es complejo por ser una sensación que se percibe y por las características electromagnéticas. Los dientes varían espacialmente porque son curvados, tienen prolongaciones relativamente pequeñas y vistas en contra de una variable de fondo no uniforme así como típicamente una iluminación no estandarizada, por lo cual difieren en relación con su colorimetría, por lo que el estudio del color es fundamental en la odontología. En la actualidad hay métodos para evaluar el color, desde una simple revisión visual hasta instrumentos como el colorímetro y los espectrofotómetros, los cuales son aparatos utilizados en la medida del color de un objeto a través de su longitud de onda reflejada. Una pigmentación dental se produce por varios factores, ya sean intrínsecos y extrínsecos, estas pigmentaciones son factores importantes tanto en la estética como en el aspecto físico, por lo que es importante poder evaluar la estabilidad de los dientes naturales ante diferentes sustancias que podrían modificar su color natural. En este estudio nos dimos a la tarea de evaluar el cambio de color de dientes naturales ante diferentes bebidas, se eligieron tres bebidas pigmentantes y de uso común: café, vino tinto y jugo de arándano; se utilizaron 10 dientes unirradiculares del mismo color previamente analizados con el espectrofotómetro. Un diente fue la muestra control y los nueve restantes se sumergieron en frascos separados con 10 mL de las tres bebidas elegidas. Realizando la evaluación de color a los 15, 30 y 90 días con ayuda del espectrofotómetro, pudimos observar que el diente sumergido en café no tuvo variación durante los primeros 15 días y el cambio más notable de color fue hasta los 90 días a diferencia de las muestras sumergidas en vino y jugo de arándano cuya variación máxima de color se presentó en 15 días respectivamente (AU)


Color is a visual effect of light rays reflecting and its concept is complex, for being a sensation that is perceived and for the electromagnetic characteristics. Teeth vary spatially because they are curved, have relatively small extensions, and are viewed against a non-uniform background variable as well as typically non-standardized illumination, which is why they differ in relation to their colorimetry. So the study of color is fundamental in dentistry. Currently, there are methods to evaluate color, from a simple visual check to instruments such as the colorimeter and spectrophotometers, which are devices used to measure the color of an object through its reflected wavelength. A dental pigmentation is produced by various factors, both intrinsic and extrinsic, these pigmentations are currently important factors in both aesthetics and physical appearance, so it is important to be able to evaluate the stability of natural teeth against different substances that could modify its natural color. In this study, we undertook the task of evaluating the change in the color of natural teeth when faced with different beverages. Three pigment and commonly used beverages were chosen: coffee, red wine and cranberry juice; 10 single-rooted teeth of the same color previously analyzed with the spectrophotometer were used. One tooth was the control sample and the remaining nine were immersed in separate bottles with 10 mL of the three chosen drinks. Carrying out the color evaluation at 15, 30 and 90 days with the help of the spectrophotometer, we could see that the tooth immersed in coffee did not change during the first 15 days and the most notable change in color was up to 90 days, unlike the samples immersed in wine and cranberry juice whose maximum color variation was presented in 15 days respectively (AU)


Subject(s)
Humans , Tooth Discoloration , Beverages , Color , Colorimetry , Esthetics, Dental , Spectrophotometry/methods , Wine , In Vitro Techniques , Epidemiology, Descriptive , Statistical Analysis , Coffee , Juices , Light
2.
Vive (El Alto) ; 3(9): 227-246, dic. 2020. ilus
Article in Spanish | LILACS | ID: biblio-1252340

ABSTRACT

INTRODUCCIÓN: las infecciones fúngicas ocasionadas por levaduras del género Cándida son extremadamente comunes en mujeres de edad reproductiva, y constituyen un motivo de atención medica de salud. OBJETIVO: evaluar la susceptibilidad de Cándidas spp, mediante el método colorimétrico (Integral Yeast System Plus). MÉTODO: fue de tipo descriptivo, transversal; se recopiló información mediante observación directa en campo y el análisis documental para obtener información bibliográfica de tipo secundaria. RESULTADOS: de los 72 casos encontrados de Cándida Albicans revela que son susceptibles a la anfotericina B (2ug/ml); de los 5 casos encontrados de Cándida Krusei revela que son sensibles a la Anfotericina B (2ug/ml); De 1 caso encontrado de Cándida Parapsilosis revela sensibilidad en la Nistatina (1.25ug/ml). En este estudio la prevalencia de la infección por Cándida fue del (44.98%). CONCLUSIONES: Cándida Albicans fue la especie más común aislada en las mujeres embarazadas representando un 72%, En la evaluación de la susceptibilidad a través del kit Integral System Yeast Plus se obtuvo que Cándida Albicans es susceptible a Anfotericina B, Flucitosina entre otros, en Cándida Glabrata se obtuvo que es sensible a la Nistatina, Anfotericina B, susceptible entre otros, en Cándida Krusei se obtuvo que es sensible a la Anfotericina B, Clotrimazol, Miconazol, susceptibles a la Nistatina, Voriconazol y resistente a la Flucitosina, Ketoconazol, Itraconazol y Fluconazol.


INTRODUCTION: fungal infections caused by yeast of the genus Candida are extremely common in women of reproductive age, and constitute a reason for medical health care. OBJECTIVE: to evaluate the susceptibility of Candida spp, using the colorimetric method (Integral Yeast System Plus). METHOD: it was descriptive, transversal; Information was collected through direct observation in the field and documentary analysis to obtain secondary bibliographic information. RESULTS: of the 72 cases found, Candida Albicans reveals that they are susceptible to amphotericin B (2ug / ml); of the 5 cases found, Candida Krusei reveals that they are sensitive to Amphotericin B (2ug / ml); Of 1 case found of Candida Parapsilosis reveals sensitivity in Nystatin (1.25ug / ml). In this study, the prevalence of Candida infection was (44.98%). CONCLUSIONS: Candida Albicans was the most common species isolated in pregnant women, representing 72%. In the evaluation of susceptibility through the Integral System Yeast Plus kit it was obtained that Candida Albicans is susceptible to Amphotericin B, Flucytosine among others, in Candida Glabrata was obtained that it is sensitive to Nystatin, Amphotericin B, susceptible among others, in Candida Krusei it was obtained that it is sensitive to Amphotericin B, Clotrimazole, Miconazole, susceptible to Nystatin, Voriconazole and resistant to Flucytosin, Ketoconazole, Itraconazole and Fluconazole.


INTRODUÇÃO: as infecções fúngicas causadas por leveduras do gênero Candida são extremamente comuns em mulheres em idade reprodutiva e constituem motivo de cuidados médicos. OBJETIVO: avaliar a suscetibilidade de Candida spp, por meio do método colorimétrico (Integral Yeast System Plus). MÉTODO: foi descritivo, transversal; as informações foram coletadas por meio de observação direta em campo e análise documental para obtenção de informações bibliográficas secundárias. RESULTADOS: Dos 72 casos encontrados, Cândida Albicans revelou ser suscetíveis à anfotericina B (2ug /ml); dos 5 casos encontrados, Candida Krusei revela que são sensíveis à Anfotericina B (2ug / ml); de 1 caso encontrado de Candida Parapsilosis revela sensibilidade na Nistatina (1,25ug / ml). Neste estudo, a prevalência de infecção por Candida foi (44,98%). CONCLUSÕES: Cândida Albicans foi a espécie mais comum isolada em gestantes, representando 72%. Na avaliação da susceptibilidade através do kit Integral System Yeast Plus foi obtido que Candida Albicans é suscetível à Anfotericina B, Flucitosina entre outras, em Cândida Glabrata foi obtido que é sensível a Nistatina, Anfotericina B, suscetível entre outras, em Candida Krusei foi obtido que é sensível a Anfotericina B, Clotrimazol, Miconazol, suscetível a Nistatina, Voriconazol e resistente a Flucitosina, Cetoconazol, Itraconazol e Fluconazol.


Subject(s)
Humans , Female , Pregnancy , Adult , Candida , Candida albicans , Amphotericin B , Colorimetry , Candida glabrata , Pregnant Women , Fluconazole , Prevalence , Clotrimazole , Itraconazole , Voriconazole , Flucytosine , Candida parapsilosis , Infections , Miconazole
3.
Gac. méd. Méx ; 156(5): 426-431, sep.-oct. 2020. tab, graf
Article in Spanish | LILACS | ID: biblio-1249941

ABSTRACT

Resumen Introducción: El jabón para el aseo cutáneo es de empleo común entre la población, sin embargo, es posible que cause daño a las células de la piel y modifique la barrera cutánea. Objetivo: Determinar el efecto citotóxico de los jabones en queratinocitos cultivados in vitro y correlacionarlo con la irritación clínica. Método: Se realizó una encuesta para conocer los jabones comerciales más utilizados y su cantidad; posteriormente, se evaluó su citotoxicidad en cultivos de queratinocitos humanos mediante el método de resazurina. Los jabones con mayor y menor citotoxicidad se aplicaron en piel de voluntarios sanos para evaluar su efecto en la barrera cutánea mediante ensayos de colorimetría y pérdida transepidérmica de agua. Resultados: De los jabones analizados, 37 % demostró ser tóxico para los queratinocitos in vitro. El jabón con mayor toxicidad indujo el mayor índice de eritema y pérdida transepidérmica de agua, en comparación con el jabón menos tóxico y el vehículo empleado como solución control. Conclusión: Los jabones comercializados para el aseo cutáneo pueden incluir ingredientes químicos que dañan los queratinocitos humanos y causan irritación subclínica de la barrera cutánea. Su utilización puede agravar dermatosis preexistentes, generar dermatitis xerósica o de contacto irritativa y causar atrofia y dermatoporosis.


Abstract Introduction: The use of soap for skin cleansing is common among the population. However, it is possible that it causes damage to skin cells and disrupts the skin barrier. Objective: To determine the cytotoxic effect of soaps on in vitro-cultured keratinocytes and to correlate it with clinical irritation. Method: A survey was conducted to find out the most widely used commercial soaps and their number. Subsequently, their cytotoxicity was evaluated in human keratinocyte cultures using the resazurin assay. The soaps with the highest and lowest cytotoxicity were applied to the skin of healthy volunteers to assess their effect on the skin barrier using colorimetry and transepidermal water loss (TEWL) assays. Results: Of the analyzed soaps, 37 % were shown to be toxic to keratinocytes in vitro. The soap with the highest toxicity induced the highest rate of erythema and TEWL, in comparison with the least toxic soap and the vehicle used as the control solution. Conclusion: Soaps marketed for skin cleansing can contain chemical ingredients that damage human keratinocytes and cause skin barrier subclinical irritation. Their use can worsen preexisting dermatoses, generate xerotic or irritant contact dermatitis, and cause atrophy and dermatoporosis.


Subject(s)
Humans , Soaps/adverse effects , Keratinocytes/drug effects , Skin Irritancy Tests , Irritants/adverse effects , Skin/drug effects , Soaps/chemistry , Body Water , Cells, Cultured , Dermatitis, Irritant/etiology , Colorimetry , Erythema/chemically induced , Healthy Volunteers , Hydrogen-Ion Concentration
4.
J. appl. oral sci ; 28: e20190693, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1134791

ABSTRACT

Abstract Debonding, staining and wear are usually the reasons for denture teeth replacement by new ones from same or different brands. Objective This study investigates the possible differences in color of denture teeth of the same or different brands under different illuminations, since their metameric behavior in color under specific illumination may become unacceptable. Methodology For the purpose of this study, 10 denture teeth (#11), shade A3, of 4 different brands were selected (Creopal/KlemaDental Pro, Executive/DeguDent, Cosmo HXL/DeguDent, Ivostar/Ivoclar-Vivadent). Teeth stabilized in white silicone mold and the CIELAB color coordinates of their labial surface under 3 different illumination lights (D65, F2, A) were recorded, using a portable colorimeter (FRU/WR-18, Wave Inc). ΔE*ab values of all possible pairs of teeth of the same brand (n=45) or pair combinations of different brands (n=100) under each illumination light, in a dry and wet state were calculated. Data were analyzed statistically using 3-way ANOVA, Friedman's and Wilcoxon's tests at a significance level of α=0.05. Results The results showed that brand type affected significantly L*, a* and b* coordinates (p<0.0001), illumination a* and b* coordinates (p<0.0001), but none of them was affected by the hydration state of teeth (p>0.05). Intra-brand color differences ranged between 0.21-0.78ΔΕ* units with significant differences among brands (p<0.0001), among illumination lights (p<0.0001) and between hydration states (p=0.0001). Inter-brand differences ranged between 2.29-6.29ΔΕ* units with significant differences among pairs of brands (p<0.0001), illumination lights (p<0.0001) and hydration states (p<0.0001). Conclusions Differences were found between and within brands under D65 illumination which increased under F2 or A illumination affected by brand type and hydration status. Executive was the most stable brand than the others under different illuminations or wet states and for this reason its difference from other brands is the lowest. In clinical practice, there should be no blending of teeth of different brands but if we must, we should select those that are more stable under different illuminations


Subject(s)
Humans , Lighting , Dentures , Prosthesis Coloring , Reference Values , Surface Properties/radiation effects , Materials Testing , Analysis of Variance , Colorimetry , Statistics, Nonparametric
5.
J. appl. oral sci ; 28: e20190720, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1134776

ABSTRACT

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Phototherapy/methods , Tooth Bleaching/methods , Tooth Bleaching Agents/administration & dosage , Carbamide Peroxide/administration & dosage , Hydrogen Peroxide/administration & dosage , Light , Reference Values , Spectrophotometry , Surface Properties/drug effects , Surface Properties/radiation effects , Risk Factors , Analysis of Variance , Treatment Outcome , Colorimetry , Combined Modality Therapy , Statistics, Nonparametric , Dental Enamel/drug effects , Dental Enamel/radiation effects , Dentin Sensitivity/chemically induced
6.
Arq. ciências saúde UNIPAR ; 23(3): 157-161, set-dez. 2019.
Article in Portuguese | LILACS | ID: biblio-1046142

ABSTRACT

O processo de alisamento capilar é uma prática comum realizada nos salões de beleza. O procedimento exige a utilização de substâncias com capacidade de rompimento das cadeias dissulfídricas da fibra capilar com posterior modelamento para o efeito desejado, sendo o formol um dos compostos mais utilizados para esta finalidade, porém indevidamente. De acordo com a legislação vigente, o formol só pode ser utilizado em produtos cosméticos com a função de conservante em uma concentração máxima de 0,2%. Devido a seu uso incorreto em produtos capilares o presente trabalho teve como objetivo realizar uma análise semi-quantitativa da presença de formol em amostras de alisantes capilares, bem como verificar o pH destes produtos. Foram obtidas 22 amostras de alisantes capilares doadas por salões de beleza da região de Umuarama - PR. A determinação da presença de formol foi realizada através da reação de Shiff e comparação com escala colorimétrica de concentrações padronizadas de formaldeído variando de 0,005% a 10%. A verificação do pH foi realizada através da preparação de soluções aquosas de 10% do alisante e posterior aferição em pHmetro digital. Das amostras analisadas, verificou-se 22,72% encontraram-se em conformidade, apresentando quantidade de formaldeído adequada com a legislação (até 0,2%) ou ausência do composto, enquanto que 77,28% apresentaram valores acima do permitido. Já o pH adequado foi constatado em apenas 13,64% amostras. O uso incorreto ou exagerado do formol pode acarretar danos à saúde, como cefaléia, dispnéia, queimadura, edema pulmonar e até câncer. Uma maior fiscalização deve ser realizada nos estabelecimentos que realizam procedimentos de alisamento capilar, bem como nas indústrias produtoras e ainda em importadoras, para uma melhor garantia do cumprimento da legislação tanto para a preservação da saúde dos profissionais quando dos usuários.


The hair-straightening process is a common practice in most beauty salons. The procedure requires the use of substances capable of disrupting the disulfide chains of the hair fiber with subsequent modeling for the desired effect, with formaldehyde being one of the most commonly but improperly used compounds for this purpose. According to the current legislation, formaldehyde can only be used in cosmetic products as a preservative function in a maximum concentration of 0.2%. Due to its incorrect use in capillary products, this work has the purpose of developing a semi-quantitative analysis of the presence of formaldehyde in samples of hair straighteners, as well as verifying the pH of those products. Twenty-two samples of hair straighteners were donated by beauty salons from the region of Umuarama-PR. The determination of the presence of formaldehyde was performed using the Shiff reaction and compared using the colorimetric scale for standard formaldehyde concentrations varying from 0.005% to 10%. The pH verification was carried out by the preparation of 10% aqueous solutions of the straightener and subsequent measurement in a digital pH meter. From the analyzed samples, 22.72% were found to be in compliance, presenting the amount of formaldehyde within the legislation (up to 0.2%) or absence of the compound, while 77.28% presenting values above the legal limitations. Additionally, adequate pH was verified in only 13.64% of the samples. Incorrect or exaggerated use of formaldehyde can lead to health issues, such as headache, dyspnea, burns, pulmonary edema and even cancer. Greater surveillance should be carried out in establishments that perform hair straightening procedures as well as in the producing and importing industries in order to guarantee better compliance with the legislation both for the preservation of the health of professionals and users alike.


Subject(s)
Colorimetry/methods , Formaldehyde/toxicity , Hair/chemistry , Pulmonary Edema , Burns
7.
Bol. latinoam. Caribe plantas med. aromát ; 18(6): 586-594, nov. 2019. tab
Article in English | LILACS | ID: biblio-1102647

ABSTRACT

The aim of the present study was to determine the main constituents of Scrophularia striata essential oil and to evaluate in vitro effect of essential oil on Leishmania tropica and Leishmania major promastigotes and axenic amastigotes. Chemical constituents of the extracted essential oil were separated by headspace solid-phase microextraction (HS-SPME) equipped with a PDMS/DVB fiber. The fiber was injected to gas chromatogram- mass spectroscopy (GC-MS) to determine their identity. Finally, after exposure of parasites to different concentrations of water soluble fraction of essential oil, viability of promastigotes and axenic amastigotes were investigated. Based on the HS-SPME results, 47 compounds representing 95.6% of the total oil, were identified in essential oil. Essential oil analysis showed that nonane (19.7%), α-terpineol (17.4%) and linalool (10.2%) were the most abundant compounds. This study indicates that water soluble fraction of S. striata essential oil has promising anti-leishmanial activity.


El objetivo del presente estudio fue determinar los principales componentes del aceite esencial de Scrophularia striata y evaluar el efecto in vitro del aceite esencial en promastigotes y amastigotes axénicos de Leishmania tropica y Leishmania major. Los componentes químicos del aceite esencial extraído se separaron mediante microextracción de fase sólida en el espacio superior (HS-SPME) equipado con una fibra PDMS/DVB. Para determinar su identidad la fibra se inyectó en un cromatógrafo de gases acoplado un espectrómetro de masas (GC-MS). Finalmente, después de la exposición de los parásitos a diferentes concentraciones de fracción soluble del aceite esencial en agua, se investigó la viabilidad de los promastigotes y los amastigotes axénicos. En base a los resultados de HS-SPME, se identificaron 47 compuestos que representan el 95.6% del aceite total en el aceite esencial. El análisis de aceites esenciales mostró que el nonano (19.7%), el α-terpineol (17.4%) y el linalol (10.2%) fueron los compuestos más abundantes. Este estudio indica que la fracción soluble en agua del aceite esencial de S. striata tiene una actividad antileishmanial prometedora.


Subject(s)
Oils, Volatile/pharmacology , Oils, Volatile/chemistry , Scrophularia/chemistry , Leishmania/drug effects , Terpenes/analysis , Colorimetry , Solid Phase Microextraction , Gas Chromatography-Mass Spectrometry
8.
Int. braz. j. urol ; 45(5): 916-924, Sept.-Dec. 2019. graf
Article in English | LILACS | ID: biblio-1040072

ABSTRACT

ABSTRACT Objective This study aims to investigate the association of filamin A with the function and morphology of prostate cancer (PCa) cells, and explore the role of filamin A in the development of PCa, in order to analyze its significance in the evolvement of PCa. Materials and Methods A stably transfected cell line, in which filamin A expression was suppressed by RNA interference, was first established. Then, the effects of the suppression of filamin A gene expression on the biological characteristics of human PCa LNCaP cells were observed through cell morphology, in vitro cell growth curve, soft agar cloning assay, and scratch test. Results A cell line model with a low expression of filamin A was successfully constructed on the basis of LNCaP cells. The morphology of cells transfected with plasmid pSilencer-filamin A was the following: Cells were loosely arranged, had less connection with each other, had fewer tentacles, and presented a fibrous look. The growth rate of LNCap cells was faster than cells transfected with plasmid pSilencer-filamin A (P <0.05). The clones of LNCap cells in the soft agar cloning assay was significantly fewer than that of cells stably transfected with plasmid pSilencer-filamin A (P <0.05). Cells stably transfected with plasmid pSilencer-filamin A presented with a stronger healing and migration ability compared to LNCap cells (healing rate was 32.2% and 12.1%, respectively; P <0.05). Conclusion The expression of the filamin A gene inhibited the malignant development of LNCap cells. Therefore, the filamin A gene may be a tumor suppressor gene.


Subject(s)
Humans , Male , Prostatic Neoplasms/pathology , Filamins/analysis , Filamins/physiology , Plasmids , Prostatic Neoplasms/genetics , Tetrazolium Salts , Time Factors , Wound Healing/physiology , Transfection/methods , Cells, Cultured , Blotting, Western , Colorimetry/methods , Cell Line, Tumor , Cell Proliferation , Filamins/genetics , Formazans
9.
Int. j. odontostomatol. (Print) ; 13(1): 19-22, mar. 2019. tab, graf
Article in English | LILACS | ID: biblio-990059

ABSTRACT

ABSTRACT: The objective of this study was to evaluate the color alteration of four brands of artificial teeth (Art Plus, Trilux, Bionote and Biolux), after immersion in color solutions of coffee, red wine and urucum. We used 80 artificial teeth, which were standardized with 2 mm thickness. Then, they were subjected to finishing and polishing, and divided into 4 groups (n = 05), which were immersed in one of the 3 types of dye, plus distilled water (control). The samples were immersed daily for 4 hours, then they were removed, washed in tap water, dried with absorbent paper and immersed in distilled water for the subsequent hours in a biological glasshouse at 37 ºC, for 21 days. The evaluation of the color change was made in the periods of 0, 7, 14 and 21 days, by means of the tristimulus colorimeter. The data were subjected to the ANOVA and Tukey test with a 5 % significance. The results showed that the urucum was the substance that caused the greatest staining while the coffee and the wine did not show statistical difference. Regarding trademarks, Trilux presented a statistical difference compared to the other commercial brands, revealing colorimetric alteration only in the 14-day period. It was concluded that the composition of the artificial teeth, the type of pigmenting agent and the immersion time determine the color change.


RESUMEN: El objetivo de este estudio fue evaluar la alteración de color de cuatro marcas de dientes artificiales (Art Plus, Trilux, Bionote y Biolux), después de inmersión en soluciones colorantes de café, vino tinto y urucum. Se utilizaron 80 dientes artificiales, los cuales fueron estandarizados con 2 mm de espesor. En seguida, los mismos fueron sometidos al acabado y pulido, y divididos en 4 grupos (n = 5), los cuales fueron inmersos en uno de los 3 tipos de colorante, más agua destilada (control). Las muestras permanecieron inmersas diariamente durante 4 horas, luego fueron retiradas, lavadas en agua corriente, secas con papel absorbente e inmersas en agua destilada por las horas subsiguientes en invernadero biológico a 37 ºC, por 21 días. La evaluación del cambio de color se realizó en los períodos de 0, 7, 14 y 21 días, por medio del colorímetro tristimulo. Los datos fueron sometidos a la prueba ANOVA y Tukey con un 5 % de significancia. Los resultados demostraron que el urucum fue la sustancia que provocó mayor manchado mientras que el café y el vino no presentaron diferencia estadística. En cuanto a las marcas comerciales, el Trilux presentó una diferencia estadística en comparación con las otras marcas comerciales, revelando alteración colorimétrica sólo en el período de 14 días. Se concluyó que la composición de los dientes artificiales, el tipo de agente pigmentante y el tiempo de inmersión determinan el cambio de color.


Subject(s)
Humans , Tooth, Artificial , Tooth Discoloration , Acrylic Resins , Wine , Materials Testing , Analysis of Variance , Coffee , Colorimetry , Coloring Agents , Immersion
10.
São Paulo; s.n; s.n; 2019. 82 p. graf, tab, ilus.
Thesis in Portuguese | LILACS | ID: biblio-1008499

ABSTRACT

Para efetivamente tratar uma infecção, é necessário que o antibiótico possua atividade antimicrobiana adequada e seja capaz de inibir o crescimento do microrganismo patogênico. O doseamento microbiológico é uma metodologia indicada para a análise do antimicrobiano de forma simples, quando comparado com outras metodologias. A Food and Drug Administration (FDA) tem encorajado uma abordagem proativa para introduzir inovações e benefícios associados ao processo de produção farmacêutica. A Qualidade por Design Analítico (AQbD) ajuda no desenvolvimento de métodos analíticos robustos e de baixo custo, que são aplicáveis durante todo ciclo de vida do produto. Os métodos microbiológicos tradicionais, de forma geral, apresentam baixa reprodutibilidade e alta incerteza. Desta forma, justifica-se o desenvolvimento de métodos microbiológicos alternativos para a análise de antimicrobianos empregando-se os conceitos de Qualidade por Design Analítico, com a finalidade de melhorar a reprodutibilidade e reduzir a incerteza final. O objetivo deste trabalho foi aplicar o conceito de Qualidade por Design Analítico (AQbD) no desenvolvimento de método colorimétrico para análise de sulfato de neomicina. O sulfato de neomicina é um antimicrobiano aminoglicosídeo amplamente empregado no tratamento de infecções cutâneas ou mucosas, tais como queimaduras, úlceras, e dermatites infecciosas. Métodos cromatográficos como a cromatografia líquida de alta eficiência em fase reversa, de pareamento iônico ou cromatografia iônica com derivatização (pré ou pós-coluna) são utilizados para a análise de aminoglicosídeos, inclusive sulfato de neomicina. Contudo, de acordo com as farmacopeias, o método microbiológico é o método analítico de escolha para a análise de sulfato de neomicina e outros aminoglicosídeos. A análise colorimétrica é um método amplamente utilizado para a detecção e quantificação de diferentes substâncias, incluindo o crescimento microbiano em estudos de eficácia terapêutica. Neste trabalho, propomos o uso de resazurina como marcador colorimétrico. O indicador sofre uma reação de oxido-redução na qual altera a coloração em resposta à redução química resultante do crescimento celular. O uso de microplacas para a análise colorimétrica é uma alternativa ao método realizado em tubos de ensaio. Uma alternativa ao uso de espectrofotômetros para a análise colorimétrica é o uso de aparelhos smartphones, pois são equipados com CPUs rápidas, câmeras de alta resolução e sensores de imagem. O processamento da imagem captada pela câmera do dispositivo é utilizado como um analisador colorimétrico. Portanto, a aplicação dos conceitos de Qualidade por Design Analítico (AQbD) possibilitou o desenvolvimento racional de método microbiológico colorimétrico para análise de sulfato de neomicina


o effectively treat an infection, the antibiotic must have adequate antimicrobial activity and be capable of inhibiting the growth of the pathogenic microorganism. The microbiological assay is an indicated methodology for the analysis of the antimicrobial in a simple way, when compared with other methodologies. The Food and Drug Administration (FDA) has encouraged a proactive approach to introducing innovations and benefits associated with the pharmaceutical production process. Analytical Design Quality (AQbD) assists in the development of robust, low cost analytical methods that are applicable throughout the product life cycle. Traditional microbiological methods, in general, have low reproducibility and high uncertainty. Thus, it is justified the development of alternative microbiological methods for the analysis of antimicrobials using the concepts of Quality by Analytical Design, in order to improve reproducibility and reduce final uncertainty. The objective of this work was to apply the concept of Quality by Analytical Design (AQbD) in the development of a colorimetric method for the analysis of neomycin sulfate. Neomycin Sulfate is an aminoglycoside antimicrobial widely used in the treatment of cutaneous or mucosal infections, such as burns, ulcers, and infectious dermatitis. Chromatographic methods such as reverse phase high performance liquid chromatography, ion-pairing or ion chromatography with derivatization (pre or post-column) are used for the analysis of aminoglycosides, including neomycin sulfate. However, according to pharmacopoeias, the microbiological method is the analytical method of choice for the analysis of neomycin sulphate and other aminoglycosides. Colorimetric analysis is a widely used method for the detection and quantification of different substances, including microbial growth in studies of therapeutic efficacy. In this work, we propose the use of resazurin as a colorimetric marker. The indicator undergoes an oxidation-reduction reaction in which it alters the coloration in response to the chemical reduction resulting from cell growth. The use of microplates for colorimetric analysis is an alternative to the method carried out in test tubes. An alternative to the use of spectrophotometers for colorimetric analysis is the use of smartphones because they are equipped with fast CPUs, high resolution cameras and image sensors. The image processing captured by the device's camera is used as a colorimetric analyzer. Therefore, the application of the concepts of Quality by Analytical Design (AQbD) allowed the rational development of a microbiological colorimetric method for analysis of neomycin sulfate


Subject(s)
Neomycin/classification , Colorimetry/instrumentation , Analytical Methods/analysis , Anti-Infective Agents/adverse effects , Anti-Bacterial Agents
11.
Rev. Soc. Odontol. La Plata ; 28(56): 11-18, dic. 2018. ilus, tab
Article in Spanish | LILACS | ID: biblio-980846

ABSTRACT

El propósito de este trabajo fue analizar el cierre marginal de restauraciones semipermanentes de porcelanas para método directo. Para la metodología, se utilizó un diseño experimental verdadero transversal pues se basó en variables con única medición. Los grupos se conformaron al azar. Las unidades de análisis fueron los sistemas adhesivos y el medio de fijación. Las preparaciones de las muestras se basaron en la norma ISO 11405 tanto para la mantención, confección, número de muestras y valoración. La variable utilizada fue la presión ejercida durante la polimerización del medio de fijación. Para la realización de este trabajo se realizó el análisis colorimétrico a través de la penetración de un colorante en las interfases medio de fijación diente o medio de fijación porcelana; y el análisis microscópico de las interfases producidas entre el sistema adhesivo - medio cementante y material de restauración rígida (AU)


The purpose of this work was to analyze the marginal closure of semi-permanent ceramic restorations for direct method. For the methodology, a true cross-section experimental design was used because it was based on variables with only measurement. The groups were formed randomly. The units of analysis were the adhesive systems and the fixing medium. The sample preparations were based on ISO 11405 standard for both maintenance, preparation, number of samples and assessment. The variable used was the pressure exerted during the polymerization of the fixing medium. In order to carry out this work, the colorimetric analysis was carried out through the penetration of a dye in the interfaces between the teeth or the porcelain fixation medium; and the microscopic analysis of the interfaces produced between the adhesive system - cementing medium and rigid restoration material (AU)


Subject(s)
Ceramics , Dental Leakage , Inlays , Microscopy, Electron, Scanning , Cross-Sectional Studies , Statistical Analysis , Dental Bonding , Cementation , Colorimetry , Dental Cavity Preparation
12.
Rev. Soc. Odontol. La Plata ; 28(55): 23-33, mayo 2018. ilus, tab
Article in Spanish | LILACS | ID: biblio-911564

ABSTRACT

En este trabajo se analizó el comportamiento de las posibles interfases producidas por algunos medios de fijación en la cementación de postes de fibra de vidrio. Para ello recurrimos a dos experimentos: Visualización microscópica de las posibles interfases y el análisis de la penetración de un colorante en la interfase del complejo dentina/ medio de fijación ­ poste de fibra de vidrio. Se conformaron tres grupos de diez unidades experimentales para cada experimento respectivamente. Los materiales con los que se trabajó presentan algún tipo de adhesión a la estructura dentaria. Ellos son el Cemento de Ionómero vítreo convencional, Cemento de resina con adhesivo dentinario y Cemento resinoso autoacondicionante. Con esta investigación se espera poder determinar cuál es el medio de fijación que posibilite la menor interfase en el complejo dentina-medio de fijación- poste de fibra de vidrio (AU)


In this work the behavior of the possible interfaces produced by some fixation media in the cementation of fiberglass poles was analyzed. To do this we used two experiments: Microscopic visualization of the possible interfaces and the analysis of the penetration of a dye in the interface of the dentin complex / fixation medium - glass fiber post. Three groups of ten experimental units were formed for each experiment, respectively. The materials with which they were worked present some type of adhesion to the dental structure. They are conventional Vitreous Ionomer Cement, Resin Cement with Dentin Adhesive and Self-Adhesion Resin Cement. With this research it is expected to be able to determine which is the fixation medium that allows the smallest interface in the dentine complex-fixation medium-fiber glass post (AU)


Subject(s)
Cementation , Dentin , Dentin-Bonding Agents , Glass , Glass Ionomer Cements , Post and Core Technique , Resin Cements , Ceramics , Colorimetry , Cross-Sectional Studies , Microscopy, Electron, Scanning , Zirconium
13.
Braz. j. med. biol. res ; 51(6): e7118, 2018. tab, graf
Article in English | LILACS | ID: biblio-889111

ABSTRACT

In this study, we investigated the chemical composition, and antioxidant and antibacterial properties of ethanolic extracts of propolis (EEP) from Melipona quadrifasciata quadrifasciata and Tetragonisca angustula. Chemical composition of EEP was determined by colorimetry and chromatographic (HPLC-DAD and UPLC-Q/TOF-MS/MS) analysis. Antimicrobial activity of EEP was evaluated against gram-positive (S. aureus, methicillin-resistant S. aureus, E. faecalis) and gram-negative (E. coli and K. pneumoniae) bacteria by the minimal inhibitory concentration (MIC) test using the microdilution method. Furthermore, the growth curve and integrity of cell membrane of S. aureus and E. coli were investigated using standard microbiological methods. HPLC-DAD analysis showed that the EEP of M. quadrifasciata quadrifasciata has a more complex chemical composition than the EEP of T. angustula. Moreover, UPLC-MS analyses of M. quadrifasciata quadrifascita indicated flavonoids and terpenes as major constituents. The bactericidal activity of both EEPs was higher against gram-positive bacteria than for gram-negative bacteria. The EEP from M. quadrifasciata quadrifasciata presented MIC values lower than the EEP from T. angustula for all tested bacteria. The EEP from M. quadrifasciata quadrifasciata caused lysis of the bacterial wall and release of intracellular components from both E. coli and S. aureus. Our findings indicate that the chemical composition of propolis from stingless bees is complex and depends on the species. The extract from M. quadrifasciata quadrifascita was more effective against gram-positive than gram-negative strains, especially against S. aureus and methicillin-resistant S. aureus compared to T. angustula extract, by a mechanism that involves disturbance of the bacterial cell membrane integrity.


Subject(s)
Animals , Anti-Bacterial Agents/pharmacology , Antioxidants/pharmacology , Bees/classification , Gram-Negative Bacteria/drug effects , Propolis/chemistry , Anti-Bacterial Agents/isolation & purification , Antioxidants/isolation & purification , Chromatography, High Pressure Liquid , Colorimetry , Gram-Negative Bacteria/classification , Gram-Positive Bacteria/classification , Microbial Sensitivity Tests , Tandem Mass Spectrometry
14.
Braz. oral res. (Online) ; 32: e25, 2018. tab, graf
Article in English | LILACS | ID: biblio-889489

ABSTRACT

Abstract The objective of this study was to evaluate the in vitro effects, including surface morphological characteristics and chemical elemental properties, of different mouthwash formulations on enamel and dental restorative materials, simulating up to 6 months of daily use. Human enamel samples, hydroxyapatite, composite resin, and ceramic surfaces were exposed to 3 different mouthwashes according to label directions — Listerine® Cool Mint®, Listerine® Total Care, and Listerine® Whitening — versus control (hydroalcohol solution) to simulate daily use for up to 6 months. The samples were analyzed using scanning electron microscopy (SEM), infrared spectrophotometry (µ-Fourier transform infrared microscopy), energy-dispersive X-ray (EDX) spectroscopy, and color analysis before and after exposure. No relevant changes were observed in the morphological characteristics of the surfaces using SEM techniques. The physical and chemical aspects of the enamel surfaces were evaluated using mid-infrared spectroscopy, and EDX fluorescence was used to evaluate the elemental aspects of each surface. There was no variation in the relative concentrations of calcium and phosphorus in enamel, silicon and barium in composite resin, and silicon and aluminum in the ceramic material before and after treatment. No relevant changes were detected in the biochemical and color properties of any specimen, except with Listerine® Whitening mouthwash, which demonstrated a whitening effect on enamel surfaces. Long-term exposure to low pH, alcohol-containing, and peroxide-containing mouthwash formulations caused no ultra-structural or chemical elemental changes in human enamel or dental restorative materials in vitro.


Subject(s)
Humans , Ceramics , Composite Resins , Dental Enamel/drug effects , Durapatite , Ethanol/chemistry , Ethanol/pharmacology , Mouthwashes/chemistry , Mouthwashes/pharmacology , Salicylates , Terpenes , Color , Colorimetry , Drug Combinations , Hydrogen Peroxide/chemistry , Immersion , Materials Testing , Microscopy, Electron, Scanning , Oils, Volatile/chemistry , Reference Values , Reproducibility of Results , Spectrometry, X-Ray Emission , Spectroscopy, Fourier Transform Infrared , Surface Properties/drug effects , Time Factors
15.
J. appl. oral sci ; 26: e20170536, 2018. tab, graf
Article in English | LILACS, BBO | ID: biblio-954512

ABSTRACT

Abstract While the combined effect of microwave irradiation with cleansing solutions on denture base materials has been investigated, the effects of only using microwave irradiation and, more importantly, in a long-term basis, was not studied yet. Objective The purpose of this study was to evaluate the effect of a long-term repeated microwaving on the dimensional, color and translucency stability of acrylic and polyamide denture base materials. Material and Methods Thirty two specimens (32 mm x 10 mm x 2.5 mm) from polyamide (Valplast) and PMMA (Vertex Rapid Simplified) denture base materials were made. Eight specimens from each material were immersed in distilled water (control) and 8 were subjected to microwave exposure at 450 W for 3 minutes for a period simulating 224 days of daily disinfection. Linear dimension, color change (ΔE*) and translucency parameter (TP) were measured at baseline and after certain intervals up to 224 cycles of immersion, using a digital calliper and a portable colorimeter. The results were analysed using two-way repeated measures ANOVA to estimate possible differences among predetermined cycles and material type. Regression analysis was also performed to estimate the trend of changes with time. Statistical evaluations performed at a significance level of 5%. Results Data analysis showed significant changes in length at baseline with an increasing number of cycles (p<0.05) and a significant interaction of cycle-material (p<0.001). The ΔΕ* parameter was significantly higher with a higher number of cycles (p<0.001), but it did not vary between materials (p>0.05). TP decreased similarly in both materials following microwave action but in a significantly higher level for Valplast (p<0.001). Conclusions The results indicated that long-term repeated microwaving affects linear dimensional, color and translucency changes of both materials. Differences between PMMA and polyamide material were noted only in dimension and translucency changes.


Subject(s)
Prosthesis Coloring , Polymethyl Methacrylate/radiation effects , Denture Bases , Microwaves , Nylons/radiation effects , Reference Values , Surface Properties , Time Factors , Materials Testing , Water/chemistry , Disinfection/instrumentation , Disinfection/methods , Reproducibility of Results , Analysis of Variance , Color , Colorimetry/methods , Polymethyl Methacrylate/chemistry , Interferometry/methods , Nylons/chemistry
16.
Braz. oral res. (Online) ; 32: e49, 2018. tab, graf
Article in English | LILACS | ID: biblio-952140

ABSTRACT

Abstract The influence of inorganic filler content of resin-based luting agents (RBLAs) on color change (ΔE00), CIEL*a*b* (individual color coordinates), and translucency parameters (TP) of simulated ceramic laminate veneer (CLV) was investigated. RBLAs with low, intermediate, and high inorganic filler content (55%, 65%, and 75% mass fractions, respectively) were prepared. Feldspar ceramic (Vitablocs Mark II) specimens (1.2 mm × 0.8 mm, A1C shade) were bonded to simulated composite resin substrates (1.6 mm × 1.2 mm, A2D shade) using three experimental and a commercial (RelyX Veneer) RBLA (translucent shade). The ΔE00 was calculated by CIEDE2000 color difference metric under three conditions (before, immediately after, and 24 h after luting). The TP was calculated using CIEL*a*b* color coordinates measured over white and black backgrounds. Surface morphology of the RBLAs was analyzed. One-way and two-way analyses of variance with a post-hoc Tukey's test were used respectively to calculate TP, CIEL*a*b* coordinates, and ΔE00 (α= 0.05). Overall, the tested RBLAs presented clinically visible ∆E00 values under the three conditions evaluated. For all RBLAs, higher ∆E00 values were observed between measurements obtained before and immediately after luting. Different inorganic filler content did not significantly increase the opacity of the ceramic-luting agents-resin composite set. The variation in inorganic filler content did not influence significantly the TP of simulated CLV; although all of the experimental RBLAs tested yielded ∆E00 above the perceptibility threshold. The L*, a*, and b* individual color coordinates were cementation-dependent.


Subject(s)
Prosthesis Coloring/methods , Resin Cements/chemistry , Dental Veneers , Reference Values , Surface Properties , Time Factors , Materials Testing , Microscopy, Electron, Scanning , Ceramics/chemistry , Reproducibility of Results , Color , Colorimetry , Statistics, Nonparametric
17.
Article in English | WPRIM | ID: wpr-775184

ABSTRACT

BACKGROUND@#The ammonia contained in tobacco fillers and mainstream and sidestream cigarette smoke accelerates nicotine dependence in cigarette smokers. Ammonia has been included in the non-exhaustive priority list of 39 tobacco components and emissions of cigarette published by the World Health Organization (WHO) Study Group on Tobacco Product Regulation. The development of a simple ammonia detection method will contribute to the establishment of tobacco product regulation under tobacco control policies and allow surveys to be conducted, even by laboratories with small research budgets.@*METHODS@#We developed a simple colorimetric method based on the salicylate-chlorine reaction and absorption spectrometry with two reagents (sodium nitroprusside and sodium dichloroisocyanurate). To compare this method to conventional ion chromatography, we analyzed the ammonia levels in tobacco fillers extracted from 35 Japanese commercially marketed cigarette brands manufactured by four tobacco companies (Japan Tobacco (JT) Inc., British American Tobacco (BAT), Philip Morris Japan, and Natural American Spirit). We also analyzed the ammonia levels in the sidestream smoke from cigarettes of the brands that were found to contain high or low tobacco filler ammonia levels.@*RESULTS@#The ammonia levels in the reference cigarette (3R4F) measured by our method and ion chromatography were similar and comparable to previously reported levels. The ammonia levels in tobacco fillers extracted from 35 cigarette brands ranged from 0.25 to 1.58 mg/g. The mean ammonia level of JT cigarette brands was significantly higher (0.83 ± 0.28 mg/g) than that of Natural American Spirit cigarette brands (0.30 ± 0.08 mg/g) and lower than those in the other two cigarette brands (1.11 ± 0.19 mg/g for BAT and 1.24 ± 0.15 mg/g for Philip Morris) (p < 0.001 by Bonferroni test). The ammonia levels in the sidestream smoke of CABIN, Marlboro Black Menthol, American Spirit Light, and Seven Stars were 5.89 ± 0.28, 5.23 ± 0.12, 6.92 ± 0.56, and 4.14 ± 0.19 mg/cigarette, respectively. The ammonia levels were higher in sidestream smoke than in tobacco filler.@*CONCLUSIONS@#Our simple colorimetric could be used to analyze ammonia in tobacco fillers and sidestream smoke. There were significant differences between the ammonia levels of the 35 commercially marketed cigarette brands in Japan manufactured by four tobacco manufacturers. Over 90% of the ammonia in sidestream smoke was in gaseous phase.


Subject(s)
Ammonia , Colorimetry , Methods , Japan , Smoke , Spectrophotometry , Methods , Tobacco , Chemistry , Tobacco Products
18.
Article in Chinese | WPRIM | ID: wpr-773294

ABSTRACT

OBJECTIVE@#This study aimed to compare the effect of D55 and D65 light sources on the visual colorimetry performance of dental students by using a homemade light-source shelf.@*METHODS@#Two Vitapan 3D-Master shade guides were randomly selected. One set was used as shade guides. Ten commonly used shade tabs of 2L2.5, 2M2, 2R2.5, 3M2, 3R2.5, 3L1.5, 3R1.5, 3L2.5, 4R1.5, and 4L1.5 were selected from the other set with covered value marks and numbered from 1 to 10. After the colorimetric training, 49 undergraduate dental students were randomly divided into two groups. Each student randomly selected two of the 10 shade tabs, and the colors were subsequently matched under D65 and D55 light sources from a distance of approximately 40 cm. The average color difference (ΔE) between the color selected by each participant and the actual color of shade tabs was calculated. Paired t test was used for statistical analysis.@*RESULTS@#The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D55 light source varied from 0 to 6.540. The average value was 2.501. The ΔE values between the color selected by each participant and the actual color of the shade tabs under the D65 light source varied from 0 to 6.610. The average value was 2.530. No statistically significant difference was observed between the results under the two light sources (P=0.921).@*CONCLUSIONS@#Both D55 and D65 daylight lamps can be used for daily dental colorimetry. These two different color temperatures showed no significant difference.


Subject(s)
Color , Colorimetry , Dental Prosthesis Design , Humans , Prosthesis Coloring , Students, Dental
19.
Mycobiology ; : 269-277, 2018.
Article in English | WPRIM | ID: wpr-729771

ABSTRACT

The production of water-soluble pigments by fungal strains indigenous to South Korea was investigated to find those that are highly productive in submerged culture. Among 113 candidates, 34 strains that colored the inoculated potato dextrose agar medium were selected. They were cultured in potato dextrose broth and extracted with ethanol. The productivity, functionality (radical-scavenging activities), and color information (CIELAB values) of the pigment extracts were measured. Five species produced intense yellowish pigments, and two produced intense reddish pigments that ranked the highest in terms of absorbance units produced per day. The pigment extracts of Penicillium miczynskii, Sanghuangporus baumii, Trichoderma sp. 1, and Trichoderma afroharzianum exhibited high radical-scavenging activity. However, the S. baumii extract showed moderate toxicity in the acute toxicity test, which limits the industrial application of this pigment. In conclusion, P. miczynskii KUC1721, Trichoderma sp. 1 KUC1716, and T. afroharzianum KUC21213 were the best fungal candidates to be industrial producers of safe, functional water-soluble pigments.


Subject(s)
Agar , Colorimetry , Efficiency , Ethanol , Fungi , Glucose , Korea , Penicillium , Solanum tuberosum , Toxicity Tests, Acute , Trichoderma
20.
Braz. dent. j ; 28(6): 669-674, Nov.-Dec. 2017. tab, graf
Article in English | LILACS | ID: biblio-888713

ABSTRACT

Abstract Recently, the non-albicans Candida species have become recognized as an important source of infection and oral colonization by association of different species in a large number of immunosuppressed patients. The objective of this study was to evaluate the interactions between C. krusei and C. glabrata in biofilms formed in vitro and their ability to colonize the oral cavity of mouse model. Monospecies and mixed biofilms were developed of each strain, on 96-well microtiter plates for 48 h. These biofilms were analyzed by counting colony-forming units (CFU/mL) and by determining cell viability, using the XTT hydroxide colorimetric assay. For the in vivo study, twenty-four mice received topical applications of monospecie or mixed suspensions of each strain. After 48 h, yeasts were recovered from the mice and quantified by CFU/mL count. In the biofilm assays, the results for the CFU/mL count and the XTT assay showed that the two species studied were capable of forming high levels of in vitro monospecie biofilm. In mixed biofilm, the CFU of C. krusei increased (p=0.0001) and C. glabrata decreased (p=0.0001). The metabolic activity observed in XTT assay of mixed biofilm was significantly reduced compared with a single C. glabrata biofilm (p=0.0001). Agreeing with CFU in vitro count, C. glabrata CFU/mL values recovered from oral cavity of mice were statistically higher in the group with single infection (p=0.0001) than the group with mixed infection. We concluded that C. krusei inhibits C. glabrata and takes advantage to colonize the oral cavity and to form biofilms.


Resumo Recentemente, as espécies não albicans tem se tornado uma importante fonte de infecção e de colonização oral pela associação de espécies em um grande número de pacientes imunossuprimidos. O objetivo desse estudo foi avaliar a interação entre C. krusei e C. glabrata em biofilmes formados in vitro e sua capacidade em colonizar a cavidade oral em modelo de camundongo. Biofilmes monoespécies e mistos foram formados em placas de 96 poços por 48 h. Esses biofilmes foram analisados pela contagem de UFC/mL e pela determinação da viabilidade celular, usando ensaio de XTT. Para o estudo in vivo, vinte e quatro camundongos receberam aplicações tópicas de suspensões monoespécies e mistas de cada espécie. Após 48 h, as leveduras foram recuperadas dos camundongos e quantificadas por UFC/mL. Nos ensaios de biofilme, os resultados da contagem de UFC/mL e do ensaio de XTT mostraram que as duas espécies estudadas foram capazes de formar grande quantidade de biofilme monoespécie in vitro. Nos biofilmes mistos, a UFC/mL de C. krusei aumentou (p=0,0001) e de C. glabrata diminuiu (p=0,0001). A atividade metabólica observada no ensaio de XTT nos biofilmes mistos foi significantemente reduzida comparada com o biofilme formado apenas de C. glabrata (p=0,0001). Concordado com as contagens in vitro, os valores de UFC/mL de C. glabrata recuperados da cavidade oral dos camundongos foram estatisticamente maior no grupo com infecção simples (p=0,0001) do que do grupo com infecção mista. Nós concluímos que C. krusei inibe C. glabrata e possui vantagem em colonizar a cavidade oral e formar biofilmes.


Subject(s)
Mice , Candida/physiology , Species Specificity , In Vitro Techniques , Candida/classification , Colony Count, Microbial , Colorimetry , Biofilms , Microbial Interactions
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