Avaliação in vitro da eficácia da fotoativação no clareamento dental utilizando a técnica em consultório

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Correlación entre diferentes métodos de evaluación de color en el clareamiento dental. Correlation between different methods for co

The aim of this study was to evaluate the correlation of color change on bleaching tooth through delta E (ΔE) by the spectrophotometer Spectroshade (SS) and digital program Scanwhite (SW). Methods: 25 patient volunteers were recruited from Operative Dentistry at Universidad de Chile Dental School, between 18 to 30 years, with good oral hygiene. Exclusion criteria: Previous experienced tooth bleaching, anterior restorations, cervical lesions, pain dental, pregnant patient, stained teeth, malposition of the teeth and periodontal pathology. The bleaching was made in two sessions with three different bleaching systems which were randomly. The assessment of color change through ΔE was made on the two upper central incisors (N=50) by the SS and SW. The color in the same teeth were measured before (T0) and after (T1) of the bleaching treatment. Data were analyzed using test Spearman correlation coefficient (Rho) with a significant level of 95%. Results: The results showed a positive and significant correlation (0.676), with a statistically significant difference (p<0.05). Conclusion: There is correlation in the measurement of color change on bleaching tooth by SS and SW.

Instrumentación para el registro del color en odontología

Color is an important variable in cosmetic dentistry, and it has traditionally been measured by a visual method, comparing teeth with standard color guides. In recent decades, electronic instruments have been developed to eliminate the subjective factor of visual measurement. This objective method has mainly been performed with colorimeters, spectrophotometers and the analysis of images obtained with digital cameras. These instruments have proven to be reliable with a high degree of precision and accuracy. Its use is recommended as an adjunctive tool to assess color in direct and indirect restorations, in aesthetic treatments like bleaching, and to facilitate communication with the dental laboratory. The spectrophotometer is the device that has reported better “in- vitro “ and “in -vivo” performance, being the “Vita Easyshade “ the one with more reliable results.

Different esthetic techniques used in combination to improve the smile

This is a clinical case report of a patient who presented with dental stains in the buccal and proximal aspects of the anterior teeth. Buccal stains were removed using the enamel microabrasion technique, and vital tooth bleaching with carbamide peroxide was also performed. Restorative procedures employing composite resin were done for a better result in the proximal aspect of teeth. Clinical significance: The authors observed the combination of these esthetic techniques improved the patient's smile. Today, dental esthetics attempts to imitate natural teeth by making them white, well-shaped, and aligned with no spots. This has enabled the development of several esthetic techniques, such as microabrasion to remove dental enamel surface stains and surface irregularities,1-6 and vital tooth bleaching to treat yellowish teeth.7 The enamel microabrasion technique uses different abrasive agents associated with chemical solutions,1,2,4,6 allowing the removal of intrinsic, hard-texture stains, and different coloring spots on the enamel surface, as well as correction of irregularities on the dental buccal surface.1,8 The various microabrasive products include the Opalustre® (Ultradent Products, http://www.ultradent.com)or Prema® Compound (Premier Dental Products, http://www.premusa.com), a low-concentration hydrochloric acid product associated with silica microparticles that is certainly effective for microabrasion technique,4,6,9,10 providing a good safety profile for the patient and professional. The microabrasion technique also promotes micro-reduction on the adamantine surface.4,5,10 In some cases, after its completion, microabrasion may cause teeth to become darker or yellowish because of the thinner remaining enamel surface, leading to more evident observation of the dentinal tissue, which in general determines tooth color. In these clinical conditions, correction of the color pattern of dental elements can be obtained with carbamide peroxide products applied in custom trays, such as the bleaching products Whiteness Perfect at 10% or 16% (FGM Productos Odontologicos, http://www.fgm.ind.br) or Opalescence® at 10% or 15% (Ultradent Products), with a considerable margin of clinical success, provided it is well indicated, well performed, and supervised by the professional.4,6,9,10 Considering all the aforementioned aspects, the authors present a clinical case about a dental-enamel microabrasion technique used to remove buccal enamel surface stains associated with dental vital bleaching and restorative procedures in the proximal aspect of anterior teeth. - See more at: https://www.dentalaegis.com/cced/2010/08/different-esthetic-techniques-used-in-combination-to-recover-the-smile#sthash.McFoH7El.dpuf

Positively Impacting the Retention Rates and Performance for Students-of-Color

This session reports on a first-year program designed to assist students-of-color in adjusting to higher education. Session participants will have the opportunity to view the overall structure of the program, including training components, academic tracking methodology, assessment and technology, enhancement programs, and additional services that S.T.A.R.S. provides.

Efecto del color del oponente en el desencadenamiento de la agresividad en los machos de Betta splendens

[ES] Los machos de Betta splendens se muestran más agresivos ante la presencia de otros machos de la misma especie y color similar al suyo, en comparación con la agresividad desplegada ante machos de tonalidad distinta

SED Stroop Effect Detector prototype

[ES] El Detector de Efectos Stroop (SED - Stroop Effect Detector), es una herramienta informática de asistencia, desarrollada a través del programa de investigación de Desarrollo Tecnológico Social de la Universidad de Las Palmas de Gran Canaria, que ayuda a profesionales del sector neuropsicológico a identificar problemas en la corteza orbitofrontal de un individuo, usándose para ello la técnica ideada por Schenker en 1998. Como base metodológica, se han utilizado los conocimientos adquiridos en las diferentes materias de la adaptación al grado en Ingeniería Informática como Gestión del Software, Arquitectura del Software y Desarrollo de Interfaces de Usuario así como conocimiento adquirido con anterioridad en asignaturas de Programación e Ingeniería del Software I y II. Como para realizar este proyecto sólo el conocimiento informático no era suficiente, he realizado una labor de investigación acerca del problema, teniendo que recopilar información de otros documentos científicos que abordan el tema, consultas a profesionales del sector como son el Doctor Don Ayoze Nauzet González Hernández, neurólogo del hospital Doctor Negrín de Las Palmas de Gran Canaria y el psicólogo Don José Manuel Rodríguez Pellejero que habló de este problema en clase del máster de Formación del Profesorado y que actualmente estoy cursando. Este trabajo presenta el test de Stroop con las dos versiones de Schenker: RCN (Reading Color Names) y NCW (Naming Colored Words). Como norma general, ambas pruebas presentan ante los sujetos estudios palabras (nombres de colores) escritas con la tinta de colores diferentes. De esta forma, el RCN consiste en leer la palabra escrita omitiendo la tonalidad de su fuente e intentando que no nos influya. Por el contrario, el NCW requiere enunciar el nombre del color de la tinta con la que está escrita la palabra sin que nos influya que ésta última sea el nombre de un color.

Allelic Heterogeneity at the Equine KIT Locus in Dominant White (W) Horses

White coat color has been a highly valued trait in horses for at least 2,000 years. Dominant white (W) is one of several known depigmentation phenotypes in horses. It shows considerable phenotypic variation, ranging from approximately 50% depigmented areas up to a completely white coat. In the horse, the four depigmentation phenotypes roan, sabino, tobiano, and dominant white were independently mapped to a chromosomal region on ECA 3 harboring the KIT gene. KIT plays an important role in melanoblast survival during embryonic development. We determined the sequence and genomic organization of the approximately 82 kb equine KIT gene. A mutation analysis of all 21 KIT exons in white Franches-Montagnes Horses revealed a nonsense mutation in exon 15 (c.2151C>G, p.Y717X). We analyzed the KIT exons in horses characterized as dominant white from other populations and found three additional candidate causative mutations. Three almost completely white Arabians carried a different nonsense mutation in exon 4 (c.706A>T, p.K236X). Six Camarillo White Horses had a missense mutation in exon 12 (c.1805C>T, p.A602V), and five white Thoroughbreds had yet another missense mutation in exon 13 (c.1960G>A, p.G654R). Our results indicate that the dominant white color in Franches-Montagnes Horses is caused by a nonsense mutation in the KIT gene and that multiple independent mutations within this gene appear to be responsible for dominant white in several other modern horse populations.

Preference polymorphism for coloration but no speciation in a population of Lake Victoria cichlids

Female mating preference based on male nuptial coloration has been suggested to be an important source of diversifying selection in the radiation of Lake Victoria cichlid fish. Initial variation in female preference is a prerequisite for diversifying selection; however, it is rarely studied in natural populations. In clear water areas of Lake Victoria, the sibling species Pundamilia pundamilia with blue males and Pundamilia nyererei with red males coexist, intermediate phenotypes are rare, and most females have species-assortative mating preferences. Here, we study a population of Pundamilia that inhabits turbid water where male coloration is variable from reddish to blue with most males intermediate. We investigated male phenotype distribution and female mating preferences. Male phenotype was unimodally distributed with a mode on intermediate color in 1 year and more blue-shifted in 2 other years. In mate choice experiments with females of the turbid water population and males from a clearer water population, we found females with a significant and consistent preference for P. pundamilia (blue) males, females with such preferences for P. nyererei (red) males, and many females without a preference. Hence, female mating preferences in this population could cause disruptive selection on male coloration that is probably constrained by the low signal transduction of the turbid water environment. We suggest that if environmental signal transduction was improved and the preference/color polymorphism was stabilized by negative frequency-dependent selection, divergent sexual selection might separate the 2 morphs into reproductively isolated species resembling the clear water species P. pundamilia and P. nyererei.

A Comparative Evaluation of Three Skin Color Detection Approaches

Skin segmentation is a challenging task due to several influences such as unknown lighting conditions, skin colored background, and camera limitations. A lot of skin segmentation approaches were proposed in the past including adaptive (in the sense of updating the skin color online) and non-adaptive approaches. In this paper, we compare three skin segmentation approaches that are promising to work well for hand tracking, which is our main motivation for this work. Hand tracking can widely be used in VR/AR e.g. navigation and object manipulation. The first skin segmentation approach is a well-known non-adaptive approach. It is based on a simple, pre-computed skin color distribution. Methods two and three adaptively estimate the skin color in each frame utilizing clustering algorithms. The second approach uses a hierarchical clustering for a simultaneous image and color space segmentation, while the third approach is a pure color space clustering, but with a more sophisticated clustering approach. For evaluation, we compared the segmentation results of the approaches against a ground truth dataset. To obtain the ground truth dataset, we labeled about 500 images captured under various conditions.

A COMPARISON OF TWO METHODS FOR THE DETECTION OF FECAL POLLUTION IN DRINKING WATER (HYDROGEN SULFIDE, INDICATOR, MODIFICATION)

A new technique for the detection of microbiological fecal pollution in drinking and in raw surface water has been modified and tested against the standard multiple-tube fermentation technique (most-probable-number, MPN). The performance of the new test in detecting fecal pollution in drinking water has been tested at different incubation temperatures. The basis for the new test was the detection of hydrogen sulfide produced by the hydrogen sulfide producing bacteria which are usually associated with the coliform group. The positive results are indicated by the appearance of a brown to black color in the contents of the fermentation tube within 18 to 24 hours of incubation at 35 (+OR-) .5(DEGREES)C. For this study 158 water samples of different sources have been used. The results were analyzed statistically with the paired t-test and the one-way analysis of variance. No statistically significant difference was noticed between the two methods, when tested 35 (+OR-) .5(DEGREES)C, in detecting fecal pollution in drinking water. The new test showed more positive results with raw surface water, which could be due to the presence of hydrogen sulfide producing bacteria of non-fecal origin like Desulfovibrio and Desulfomaculum. The survival of the hydrogen sulfide producing bacteria and the coliforms was also tested over a 7-day period, and the results showed no significant difference. The two methods showed no significant difference when used to detect fecal pollution at a very low coliform density. The results showed that the new test is mostly effective, in detecting fecal pollution in drinking water, when used at 35 (+OR-) .5(DEGREES)C. The new test is effective, simple, and less expensive when used to detect fecal pollution in drinking water and raw surface water at 35 (+OR-) .5(DEGREES)C. The method can be used for qualitative and/or quantitative analysis of water in the field and in the laboratory. ^

El color en las aceitunas negras naturales de mesa : nueva técnica de mensura digitalizada para optimizar el método de oscurecimiento natural

Se aplicó un nuevo método para la evaluación objetiva del color en aceitunas de mesa, basado en el análisis de la intensidad de reflexión de cada uno de los colores primarios que componen la luz blanca (rojo, verde y azul), según las longitudes de onda del Sistema RGB. Se trabajó con programas informáticos para el análisis de imágenes digitales color tipo BMP de 24 bits. Este trabajo proporciona mayor información sobre el pardeamiento de las aceitunas naturales en salmuera, lo que sería muy útil para incrementar la efectividad del proceso. El método propuesto es rápido y no destructivo, prometiendo ser muy práctico ya que permite que una misma muestra pueda ser evaluada en el tiempo. Se investigaron los cambios de color en aceitunas elaboradas naturalmente, con diferentes grados de madurez (pintas, rojas y negras) y a diferentes valores de pH (3,6 - 4,0 - 4,5), expuestas al aire durante períodos crecientes de tiempo. Se cuantificó el grado de oscurecimiento a través de Índices de Intensidad de Reflexión. La evolución del índice de reflexión en función del tiempo generó una curva polinomial de 4° grado que reveló el comportamiento sigmoidal del fenómeno de pardeamiento enzimático, con la máxima correlación a las 8 horas de aireación. Esta función permitiría predecir el fenómeno de pardeamiento en las aceitunas negras y representa una medición objetiva del grado relativo de pardeamiento. La evolución del color rojo (λ = 700,0 nm) exhibió la mayor correlación con el proceso de pardeamiento. Las aceitunas rojas naturales a pH 4,5 presentaron óptimo pardeamiento. El espectro de reflexión para el color azul (λ = 435,8 nm) se sugiere como medida de la actividad de la enzima PPO (polifenoloxidasa).

(Table 1) Color, Fe-C-S chemistry and carbonate content from ODP Sites 172-1062 and 172-1063

Reflectance spectra collected during ODP Leg 172 were used in concert with solid phase iron chemistry, carbonate content, and organic carbon content measurements to evaluate the agents responsible for setting the color in sediments. Factor analysis has proved a valuable and rapid technique to detect the local and regional primary factors that influence sediment color. On the western North Atlantic drifts, sediment color is the result of primary mineralogy as well as diagenetic changes. Sediment lightness is controlled by the carbonate content while the hue is primarily due to the presence of hematite and Fe2+/Fe3+ changes in clay minerals. Hematite, most likely derived from the Permo-Carboniferous red beds of the Canadian Maritimes, is differentially preserved at various sites due to differences in reductive diagenesis and dilution by other sedimentary components. Various intensities for diagenesis result from changes in organic carbon content, sedimentation rates, and H2S production via anaerobic methane oxidation. Iron monosulfides occur extensively at all high sedimentation sites especially in glacial periods suggesting increased high terrigenous flux and/or increased reactive iron flux in glacials.

Mercado de trabajo y condicionamiento por color de piel en grandes centros urbanos de la Argentina

La discriminación por aspecto físico, y más en particular, el trato diferenciado hacia personas cuyos rasgos remiten a un origen entendido como indígena o no-europeo, constituye un problema escasamente tratado en los estudios de la desigualdad en la Argentina. Esta carencia, sumada a la falta de una articulación en las explicaciones de estos mecanismos relacionados con las desigualdades derivadas de las condiciones de clase, con frecuencia opacan el estudio del fenómeno profundizando sus efectos de invisibilidad. En este sentido, se mantienen ocultas las dificultades que afrontan quienes poseen estos rasgos para sobreponerse a prejuicios que reeditan cotidianamente principios racistas que asocian los rasgos nativos con la delincuencia, la falta de capacidades y saberes y, en términos generales, con la inferioridad socialmente entendida. En este artículo se investiga la incidencia del trato desigual basado en el aspecto físico -en particular, en el color de piel- sobre los logros laborales en una muestra de 2.500 personas de grandes centros urbanos de la Argentina en el año 2007. La discriminación por rasgos físicos, como efecto de la persistencia de principios operativos basados en la racialización de las interacciones sociales, pone de manifiesto la continuidad de principios jerárquicos, simbólicos y materiales que obstruyen la posibilidad de una mayor igualdad en el desarrollo cotidiano de las condiciones de vida de las personas

Mercado de trabajo y condicionamiento por color de piel en grandes centros urbanos de la Argentina

La discriminación por aspecto físico, y más en particular, el trato diferenciado hacia personas cuyos rasgos remiten a un origen entendido como indígena o no-europeo, constituye un problema escasamente tratado en los estudios de la desigualdad en la Argentina. Esta carencia, sumada a la falta de una articulación en las explicaciones de estos mecanismos relacionados con las desigualdades derivadas de las condiciones de clase, con frecuencia opacan el estudio del fenómeno profundizando sus efectos de invisibilidad. En este sentido, se mantienen ocultas las dificultades que afrontan quienes poseen estos rasgos para sobreponerse a prejuicios que reeditan cotidianamente principios racistas que asocian los rasgos nativos con la delincuencia, la falta de capacidades y saberes y, en términos generales, con la inferioridad socialmente entendida. En este artículo se investiga la incidencia del trato desigual basado en el aspecto físico -en particular, en el color de piel- sobre los logros laborales en una muestra de 2.500 personas de grandes centros urbanos de la Argentina en el año 2007. La discriminación por rasgos físicos, como efecto de la persistencia de principios operativos basados en la racialización de las interacciones sociales, pone de manifiesto la continuidad de principios jerárquicos, simbólicos y materiales que obstruyen la posibilidad de una mayor igualdad en el desarrollo cotidiano de las condiciones de vida de las personas