Parámetros para la evaluación visual e instrumental del color dental en estudios in-vitro. Revisión de la literatura / Parameters for visual and instrumental assessment of tooth colour in in-vitro studies. Literature review

Objetivo: establecer los parámetros para la evaluación visual e instrumental del color dental en estudios in-vitro a partir de la literatura científca publicada entre 2015 y 2021. Métodos: se realizó la búsqueda en las bases de datos: PubMed, Web of Science, Science Direct, Scopus, Scielo y Lilacs; también en el motor de búsqueda Google Académico y las bibliotecas de las editoriales Wiley y Springer. Las palabras clave utilizadas fueron tooth, color, in-vitro, color perception, shade matching, thresholds, appearance, surrounding, "CIELAB" y "CIEDE2000". Teniendo en cuenta los criterios de elegibilidad, se seleccionaron los estudios de acuerdo al título, resumen y texto completo. Resultados: la búsqueda arrojó un total de 37 publicaciones que se agruparon en tres tópicos: 1. toma de color visual: condiciones ambientales, observadores y nivelación; 2. toma de color instrumental: instrumentos; y 3. procesamiento de datos: cálculo de la diferencia de color y umbrales de perceptibilidad (PT) y aceptabilidad (AT). Conclusiones: los aspectos más importantes en la evaluación visual son la iluminación, el ambiente para registro (sitio, entorno y fondo alrededor de la muestra), las condiciones geométricas de visualización, los observadores y el uso de guías. En la evaluación instrumental es relevante elegir el aparato apropiado de acuerdo con su precisión y reproducibilidad, como los espectroradiómetros y los espectrofotómetros de uso clínico. Se presenta el procesamiento de datos para establecer las variaciones de cada coordenada, las diferencias de color (ΔE): CIELAB y CIEDE2000, los umbrales y los lineamientos.

Objective: To establish the parameters for the visual and instrumental evaluation of tooth color in in-vitro studies based on the scientifc literature published between 2015 and 2021. Methods: The search was carried out in the databases of PubMed, Web of Science, Science Direct, Scopus, Scielo, Lilacs; search engine Google Scholar and publishers' library of Wiley and Scielo, using the keywords "tooth", "color", "in vitro", "color perception", "shade matching", "thresholds", "appearance", "surrounding", "CIELAB", and "CIEDE2000". The literature was selected according to the title, abstract and full text taking into the eligibility criteria. Results: It yielded a total of 37 publications, which were grouped into three topics: 1. visual color acquisition: environmental conditions for color acquisition, observers and levelling. 2. instrumental color sampling: instruments. 3. Data processing: Calculation of color diference and perception thresholds (PT) and acceptability thresholds (AT). Conclusions: The most important aspects in the visual assessment are lighting, the environment for color registration (site, environment and background around the sample), the geometric conditions of visualization, the observers and the use of guides. Regarding the instrumental assessment of color, the appropriate devices must be chosen according to its precision and reproducibility, being the spectrophotometers and spectroradiometers the most precise ones. It is presented how the data processing is carried out to establish the variations of each coordinate, the color diferences (ΔE): CIELAB and CIEDE2000, thresholds and guidelines.

Propiedades flexurales y estabilidad de color de materiales restauradores estéticos indirectos / Flexural properties and color stability of indirect esthetic restorative materials

Introducción: Las diferencias en las propiedades mecánicas de los materiales cerámicos y a base de resina plantean la interrogante sobre cuál puede tener un mejor desempeño a largo plazo. Objetivos: Evaluar la resistencia flexural y estabilidad de color de diferentes materiales restauradores estéticos indirectos. Métodos: Los materiales seleccionados fueron Filtek™ Z250 XT (3M ESPE), Ceramage (SHOFU Dental), VITA VM® LC y VITA ENAMIC® (VITA Zahnfabrik), IPS e.max® (Ivoclar-Vivadent) y Zolid FX (Amann Girrbach AG). El ensayo de resistencia flexural (n = 10) fue realizado en una máquina universal de ensayos mecánicos. Las lecturas de color (n = 5) se midieron en un espectrofotómetro VITA Easyshade V®. Resultados: Los materiales totalmente cerámicos mostraron un mejor desempeño mecánico (p < 0,001). Los resultados de estabilidad de color muestran que Ceramage, IPS e.max® y Zolid FX, mostraron una diferencia estadísticamente significativa (p ≤ 0,002) con Filtek Z250 XT, VITA VM® LC y VITA ENAMIC®. Conclusiones: Los materiales totalmente cerámicos presentaron una mayor resistencia flexural y estabilidad de color que los materiales de base polimérica. A pesar de ello, los materiales estéticos indirectos con polímeros en su composición, como Ceramage, se presentan como una alternativa válida, ya que además de tener propiedades mecánicas adecuadas, poseen una estabilidad de color semejante a los materiales cerámicos(AU)

Introduction: Differences in the mechanical properties of ceramic and resin-based materials pose the question of which of the two will perform better in the long run. Objectives: Evaluate the flexural resistance and color stability of different indirect esthetic restorative materials. Methods: The materials selected were Filtek™ Z250 XT (3M ESPE), Ceramage (SHOFU Dental), VITA VM® LC and VITA ENAMIC® (VITA Zahnfabrik), IPS e.max® (Ivoclar-Vivadent) and Zolid FX (Amann Girrbach AG). The flexural resistance assay (n = 10) was conducted in a universal mechanical testing machine. Color readings (n = 5) were taken with a VITA Easyshade V® spectrophotometer. Results: All-ceramic materials had better mechanical performance (p < 0.001). Color stability results show that Ceramage, IPS e.max® and Zolid FX displayed a statistically significant difference (p ≤ 0.002) with respect to Filtek Z250 XT, VITA VM® LC and VITA ENAMIC®. Conclusions: All-ceramic materials exhibited greater flexural resistance and color stability than polymer-based materials. However, indirect esthetic materials with polymers in their composition, such as Ceramage, are presented as a valid alternative, due to their appropriate mechanical properties and their color stability, which is similar to that of ceramic materials(AU)

Variaciones histórico-culturales de la estética dental / Historical and cultural variations of teeth aesthetics

Resumen La estética dentaria es un tema de amplia relevancia en la odontología actual, tanto en el ambiente universitario como en la práctica privada. Cuando las personas expresan que desean una sonrisa más hermosa, dentistas y pacientes piensan automáticamente en aclarar el color de los dientes como un componente importante de este proceso. ¿Cuál es la razón de esta concordancia tácita? Algunos podrían argüir que una sonrisa saludable es naturalmente más blanca, pero sabemos que la funcionalidad fisiológica no necesariamente está asociada a una estética socialmente determinada. Es más, muchas veces los procedimientos estéticos implican modificaciones corporales que no necesariamente son naturales, ni saludables. El objetivo de esta revisión, es brindar elementos de discusión acerca de aspectos históricos y culturales relacionados con el posicionamiento del color dentario como parte importante de un ideal estético. Se pretende argumentar, que el deseo de tener dientes más blancos reside eminentemente en influencias culturales. Asimismo, se invita a la reflexión de que, si los "dientes blancos" debiesen ser equiparados a "dientes saludables", con las consecuentes ramificaciones que implicaría esta suposición, en nuestro mundo profesional.

Abstract Dental aesthetics is a topic of wide relevance in current dentistry, both in dental education and in private practice. When people express that they want a beautiful smile, both dentists and patients think of whitening tooth color. What is the reason for this tacit agreement? Some might argue that a healthy smile is naturally whiter, but we know that physiological functionality is not always associated with socially determined aesthetics. Furthermore, some aesthetics procedures might involve body modifications that are not necessarily natural nor healthy. The aim of this review is to to provide elements of discussion about historical and cultural aspects related to the positioning of tooth color as an important part of an aesthetic ideal. To argue that the desire for whiter teeth resides in cultural influences. To invite reflection if "white teeth" should be equated with "healthy teeth", with the consequences this assumption would imply in our professional field.

Valoración del grado de pigmentación en dientes acrílicos sometidos a humo del cigarrillo / Assessment of the degree of pigmentation in acrylic teeth subjected to cigarette smoke

INTRODUCCIÓN. Los cambios de color en los dientes acrílicos dependen de varios factores, con el humo de cigarrillo como uno de los principales agentes de igmentación de las prótesis. OBJETIVO. Valorar el grado de pigmentación en dientes acrílicos sometidos al humo del cigarrillo, mediante espectrofotometría digital. MATERIALES Y MÉTODOS. Estudio observacional, analítico, de caso y control. Muestra de 60 dientes acrílicos divididos en dos grupos: A (resina acrílica de 3 capas) y B (resina acrílica de 4 capas). Se subdividió en: grupo 1: dientes sometidos a humo de cigarrillo estándar con filtro de carbón; grupo 2: dientes sometidos a humo de cigarrillo estándar sin filtro; y, grupo 3: grupo control. Cada uno de éstos se expuso a 150 cigarrillos, 5 diarios durante 30 días y el grupo control fue mantenido a 37ºC en saliva artificial durante 30 días sin aplicación de humo de cigarrillo. Para la toma de color se empleó espectrofotómetro Vita Easyshade®. Los análisis se realizaron en el programa estadístico International Business Machines Statistical Package for the Social Sciences mediante la prueba de Kruskal-Wallis y comparaciones de Dunn. RESULTADOS. Se determinó que la pigmentación del grupo B fue mayor a la del grupo A, con una diferencia significativa entre ellos (p< 0,05). No se encontró datos estadísticamente significativos entre cigarrillos (con filtro - sin filtro). CONCLUSIÓN. La exposición al humo de cigarrillo pigmentó los dientes acrílicos de ambas propiedades siendo mayor en los dientes de resina acrílica de 4 capas.

INTRODUCTION. Color changes in acrylic teeth depend on several factors, with cigarette smoke as one of the main agents of denture pigmentation. OBJECTIVE. To assess the degree of pigmentation in acrylic teeth subjected to cigarette smoke, using digital spectrophotometry. MATERIALS AND METHODS. Observational, analytical, case-control study. Sample of 60 acrylic teeth divided into two groups: A (3-layer acrylic resin) and B (4-layer acrylic resin). It was subdivided into: group 1: teeth subjected to standard cigarette smoke with charcoal filter; group 2: teeth subjected to standard cigarette smoke without filter; and, group 3: control group. Each of these was exposed to 150 cigarettes, 5 daily for 30 days and the control group was maintained at 37ºC in artificial saliva for 30 days without application of cigarette smoke. Vita Easyshade® spectrophotometer was used for color determination. The analyses were performed in the statistical program International Business Machines Statistical Package for the Social Sciences using the Kruskal-Wallis test and Dunn's comparisons. RESULTS. It was determined that the pigmentation of group B was greater than that of group A, with a significant difference between them (p< 0,05). No statistically significant data was found between cigarettes (filtered - unfiltered). CONCLUSION. Cigarette smoke exposure pigmented acrylic teeth of both properties being higher in 4-layer acrylic resin teeth.

Evaluation of the color vision acuity pattern of undergraduates of health courses in a Brazilian university / Avaliação do padrão de acuidade visual para cores de acadêmicos da área de saúde em Universidade brasileira

ABSTRACT Objective: The goal of the study is to analyze the color vision acuity pattern in undergraduates of health courses and to discuss the impact of these diseases in this population. Color deficiencies interfere significantly in the daily routine of professionals in the health area who need to discern different color hues in several situations of their everyday practice. Methods: Sixty-four volunteers, undergraduates of health courses of the Federal University of Alfenas (UNIFAL-MG), participated in the study. One man was excluded because he did not fit the inclusion criteria. Two groups were analyzed according to sex with the Farnsworth Munsell 100-Hue test. Results: There were no significant differences between the eyes and between the groups analyzed. The color vision acuity pattern is between 35 and 40, according to the Total Error Score. The gender issue does not influence the general pattern of the color vision acuity of the health courses undergraduates when those with color vision disorders are removed. Conclusion: Screenings and guidance should be given to undergraduates of health courses so that, aware of their condition of presenting some type of color disorder, they shall make the appropriate decision on which career to follow so that such limitation does not interfere with the quality of their daily life.

RESUMO Objetivo: O objetivo do estudo é analisar a acuidade visual média para cores de estudantes da área de saúde e discutir o impacto das doenças que a afetam nessa população. Deficiências cromáticas interferem de forma significativa no dia a dia de profissionais da área da saúde que necessitam de discernir diferentes matizes em diversas situações de sua prática profissional. Métodos: Participaram da pesquisa 64 voluntários, estudantes de cursos da área de saúde da Universidade Federal de Alfenas, sendo que 1 homem foi excluído por não se adequar aos critérios de inclusão. Dois grupos foram analisados, de acordo com o sexo, com o teste de Farnsworth Munsell 100-Hue. Resultados: Não houve diferenças significativas entre os olhos e entre os grupos analisados. O padrão de visão de cores encontra-se entre 35 e 40, de acordo com a Pontuação do Erro Total. A questão de gênero não influencia no padrão geral da qualidade de visão de cores de estudantes da área de saúde, quando retirados aqueles que apresentam distúrbios da visão cromática. Conclusão: Devem ser realizadas triagens e orientação para estudantes de cursos da área de saúde para que, cientes da sua condição de apresentar algum tipo de distúrbio cromático, possam tomar a decisão adequada sobre qual carreira seguir para que tal limitação não interfira na qualidade de sua vida diária.

The impact of at home and in-office bleaching agents on the color stability of bulk-fill composite resins / Impacto de agentes clareadores caseiros e de consultório na estabilidade de cor de resinas compostas bulk fill

Objective: This study compared different composites for color stability after exposure to at home and in-office bleaching gels. Material and Methods: Composite resin specimens (6mm diameterx2mm thickness) were manufactured according to the following groups (n=20): RC- Conventional; BF-Bulk Fill; RF-Flow; BFF-Bulk-Fill Flow. The surfaces were stained with coffee solution for 36h. A spectrophotometer was used to record the initial color (L*a*b*). Half of the specimens from each group underwent bleaching with 35% hydrogen peroxide (in-office) in three 45-minute applications. New color measurements were performed after 7, 14 and 21 days. The other half of the specimens underwent bleaching with 22% carbamide peroxide (at home) in 14 1-hour applications. Further color measurements were performed after 7 and 14 days. For comparison between the color coordinates in different periods, ANOVA for repeated measures was applied (α=5%). The color variation (ΔE) was calculated for each group. Results: For in-office bleaching, there were no significant differences between the periods b* coordinate of the RF group, and for L* and b* coordinates of the BFF group. For at home bleaching the groups BF and BFF showed no differences for the L* coordinate. For the other coordinates, there was difference between the initial periods and after 14 days. The ΔE variation presented higher values for the at home bleaching groups. For both whiteners the bulk-fill resins presented the greatest color variations. Conclusions: Bulk Fill resins do not guarantee greater color stability than the other composite resins tested, including conventional flow resin. The conventional composite resin showed the lower ΔE. (AU)

Objetivo: Esse estudo comparou diferentes resinas compostas quanto a estabilidade de cor após exposição a géis clareadores de uso caseiro e de consultório. Material e Métodos: Espécimes de resina composta (6mm diâmetro x 2mm espessura) foram confeccionados de acordo com os seguintes grupos (n=20): RC- Convencional; BFBulk Fill; RF-Flow; BFF-Bulk-Fill Flow. As superfícies foram manchadas com solução de café por 36 horas. Um espectrofotômetro foi utilizado para mensurar a cor inicial (L*a*b*). Metade dos espécimes de cada grupo foi submetida ao clareamento com peróxido de hidrogênio 35% (clareamento de consultório) durante três aplicações de 45 minutos. Novas mensurações de cor foram realizadas após as aplicações de 7, 14 e 21 dias. A outra metade dos espécimes foi submetida ao clareamento com peróxido de carbamida 22% (clareamento caseiro) em 14 aplicações de 1 hora durante 14 dias. Novas mensurações de cor foram realizadas após 7 e 14 dias. Para comparação entre as coordenadas nos diferentes períodos foi aplicada a análise de variância ANOVA para medidas repetidas (α=5%). A variação de cor (ΔE) foi calculada para cada grupo. Resultados: Para o clareamento de consultório não houve diferenças significativas para a coordenada b* do grupo RF, e para L* e b* no grupo BFF. Para o clareamento caseiro os grupos BF e BFF não apresentaram diferenças para a coordenada L*. Para as outras coordenadas, houve diferenças entre os períodos inicial e após 14 dias. A variação de ΔE apresentou maiores valores para o grupo submetido ao clareamento caseiro. Para ambos clareadores a resina composta bulk fill apresentou as maiores variações de cor. Conclusões: As resinas compostas bulk fill não garantiram uma maior estabilidade de cor quando comparadas as resinas compostas tradicionais testadas, incluindo a resina flow. A resina composta convencional apresentou a menor variação de ΔE. (AU)

The reaction pattern rules of mouse retinal ganglion cell under different wavelengths of light stimulation / 中华实验眼科杂志

Objective To explore the reaction pattern rules of mouse retinal ganglion cells potential under different wavelengths of light stimulation.Methods Thirty SPF grade 3-week-old C57BL/6 mice were used for ex vivo whole mount retina preparation.The cells firing activities were recorded on patch clamp system with on cell touch mode under stimulation of 400 nm,580 nm and white light,respectively.According to different reactions to different light stimulation,the cells were classified into 400 nm sensitive RGC,580 nm sensitive RGC and color vision insensitive RGC.Then the cells were further classified according to light ON type,light ON/OFF type or light OFF type.The RGC's baseline firing pattern (baseline firing frequency,burst firing frequency) and light activation firing pattern (response pattern,light response firing frequency,light response firing amplification) were compared among different RGC classifications.Results Eighty-two RGCs were recorded in total.The frequency of spontaneous firing activity ranged from 0.00 Hz to 32.33 Hz among different RGCs.400 nm sensitive RGCs were 52 (63.41％),580 nm sensitive RGCs were 29(35.37％) and color vision insensitive RGC was 1 (1.22％).OFF type RGC was the main cell type in 400 nm sensitive group (36.29％),and ON/OFF type RGC was the main cell type in 580 nm sensitive group (34.48％).The firing amplification in 580 nm sensitive RGC was (22.93±10.23) Hz,which was significantly higher than (14.44± 10.11) Hz in 400 nm sensitive RGC (t =4.060,P =0.044).The firing amplification in 580 nm sensitive ON type RGC was (24.17±8.98)Hz,which was significantly higher than (11.12±10.35)Hz in 400 nm sensitive ON type RGC (t =5.373,P =0.021).Conclusions There is no specific firing pattern rules among different light sensitive RGCs.In the future,artificial color vision may be achieved through personalized electric stimulation and learning feedback strategy.

The reaction pattern rules of mouse retinal ganglion cell under different wavelengths of light stimulation / 中华实验眼科杂志

Objective To explore the reaction pattern rules of mouse retinal ganglion cells potential under different wavelengths of light stimulation. Methods Thirty SPF grade 3.week.old C57BL/6 mice were used for ex vivo whole mount retina preparation. The cells firing activities were recorded on patch clamp system with on cell touch mode under stimulation of 400 nm,580 nm and white light,respectively. According to different reactions to different light stimulation, the cells were classified into 400 nm sensitive RGC, 580 nm sensitive RGC and color vision insensitive RGC. Then the cells were further classified according to light ON type,light ON/OFF type or light OFF type. The RGC's baseline firing pattern ( baseline firing frequency,burst firing frequency) and light activation firing pattern (response pattern,light response firing frequency,light response firing amplification) were compared among different RGC classifications. Results Eighty.two RGCs were recorded in total. The frequency of spontaneous firing activity ranged from 0. 00 Hz to 32. 33 Hz among different RGCs. 400 nm sensitive RGCs were 52(63. 41％),580 nm sensitive RGCs were 29(35. 37％) and color vision insensitive RGC was 1(1. 22％). OFF type RGC was the main cell type in 400 nm sensitive group (36. 29％),and ON/OFF type RGC was the main cell type in 580 nm sensitive group (34. 48％). The firing amplification in 580 nm sensitive RGC was (22. 93±10. 23)Hz,which was significantly higher than (14. 44±10. 11)Hz in 400 nm sensitive RGC (t=4. 060,P=0. 044). The firing amplification in 580 nm sensitive ON type RGC was (24. 17±8. 98)Hz,which was significantly higher than (11. 12±10. 35)Hz in 400 nm sensitive ON type RGC (t=5. 373,P=0. 021). Conclusions There is no specific firing pattern rules among different light sensitive RGCs. In the future, artificial color vision may be achieved through personalized electric stimulation and learning feedback strategy.

Paradojas del color en dermatología / Paradoxes of color in dermatology

La lógica dermatológica, ha encontrado el rompimiento de los paradigmas semiológicos, desde la incorporación de la imagen digital al estudio de las lesiones de piel, características como: forma, límites, contraste, estructura y profundidad están ligadas al color. Su percepción puede objetivarse, con la ayuda de instrumentos como el dermato-colorímetro, el derma-espectrofotómetro e inclusive el dermatoscopio digital, que permiten corregir los errores de metamerismo. En esta disertación pretendemos abrir nuevas ideas, sobre la importancia de estudiar el color de la piel más allá del fototipo cutáneo, así como, reconocer el color estructurado como una variante de la semiología pigmentaria y la incorporación del estudio heurístico, en el diseño de modelos enseñanza-aprendizaje para los programas de Dermatología.

The dermatological logic study has found breaking out paradigms since the introduction of digital imaging for the study of skin disease, features like shape, boundaries, contrast, depth and structure are related to color, color perception can be objectified through instruments such as derm-colorimeter, derm-spectrophotometer and even digital dermatoscopy, which can correct the metamerism phenomenon. In this dissertation, we intend to open mind and give new ideas about the importance of studying the skin color beyond the skin phototype, recognize the structured color as a variant of the semiology of color, as well as the incorporation of models of study design teaching-learning heuristic for dermatology programs.

Fruit color preference by birds and applications to ecological restoration / Preferência de cor de frutos por aves e aplicações à restauração ecológica

Abstract Ecological restoration aims to retrieve not only the structure but also the functionality of ecosystems. Frugivorous birds may play an important role in this process due to their efficiency in seed dispersal. Color perception in these animals is highly developed, and then the colors of fleshy fruits may provide important clues for choosing plant species for restoration plans. This study aims to integrate bird color preferences and restoration of degraded areas, with an objective to evaluate the potential attractiveness to birds by colored fruits. We carried out an experiment with 384 artificial fruits made of edible modeling clay with the following colors: black, blue, green and red, with 96 fruits of each color in six sites, including four restored areas and two second-growth forest fragments. We also tested the possible effect of light intensity on fruit consumption by color. A total of 120 (38.6%) were assumed to be consumed by birds, and the fruit consumption varied in response to the location and light incidence. Consumption of black and blue fruits was not related to site by chance. Notwithstanding, red and black fruits were consumed significantly more than any other colors, emphasizing bird preference to these colors, regardless of location. Enrichment with shade tolerant shrubs or forest species with black or red fruits may be an alternative way to manage established restorations. In recently established or new restorations, one may introduce pioneer shrubs or short-lived forest species which have blue fruits, but also those having black or red ones.

Resumo A restauração ecológica tem a finalidade de recuperar não apenas a estrutura, mas também a funcionalidade dos ecossistemas, e as aves frugívoras podem desempenhar um papel importante neste processo devido à sua eficiência na dispersão de sementes. Como a percepção da cor nestes animais é altamente desenvolvida, a cor dos frutos carnosos pode ser uma característica importante na escolha de espécies de plantas para os reflorestamentos. Este estudo tem como foco integrar a preferência de cor de frutos por aves e a recuperação de áreas degradadas, objetivando determinar a atratividade potencial de aves por frutos de cores diferentes. Foi realizado um experimento com 384 frutos artificiais feitos com massa de modelar comestível nas cores preta, azul, verde e vermelha, com um total de 96 frutos em cada cor em seis locais, incluindo quatro áreas restauradas e dois fragmentos de floresta secundária. Também foi testado o possível efeito da intensidade de luz sobre o consumo de frutos conforme as cores. Um total de 120 (38,6%) frutos foi considerado consumido pelas aves, e o consumo variou em resposta aos locais e incidência de luz. O consumo de frutos pretos e azuis foi significativamente relacionado com o local. Os frutos vermelhos e pretos foram significativamente mais consumidos do que as outras cores, enfatizando a preferência aves por essas cores, independentemente do local. O enriquecimento com espécies tolerantes à sombra com frutos pretos ou vermelhos pode ser uma alternativa para manejo de restaurações já estabelecidos; enquanto nos recentemente criados podem ser introduzidas espécies pioneiras ou florestais de vida curta com frutos azuis, pretos ou vermelhos.

Influência do adesivo no resultado cromático imediato e após envelhecimento acelerado das "lentes de contato'': in vitro / Influence of the adhesive on the imediate chromatic result and after accelerated aging of non-prep veneers: an in vitro study

O objetivo deste estudo foi avaliar a influência do sistema adesivo no resultado cromático de "lentes de contato" de alta translucidez imediatamente após a cimentação e após envelhecimento artificial acelerado (EAA). Quarenta dentes bovinos e 40 discos de cerâmica (IPS eMax) cor HT-BL1 com 0,5 mm de espessura foram distribuídos em quatro grupos: GI- Scotchbond Multi-Purpose; GII - Single Bond 2; GIII - Single Bond Universal (usado no dente como adesivo apenas); e GIV - Single Bond Universal (usado no dente e na peça como silano). Os dentes e a cerâmica foram tratados previamente à cimentação, respeitando-se os grupos experimentais, e o cimento Variolink Veneer valor 0 foi utilizado para cimentação. Todos os espécimes foram submetidos a 400 h de EAA. Foi realizada a mensuração da cor com espectrofotômetro Easyshade em três momentos: 1) substrato dentário; 2) disco cimentado; e 3) após EAA. Os valores de L*, a*, b*, ΔE1* e ΔE2* foram submetidos a análise estatística em SPSS 17.0 para Windows com uma significância de 5% (p<0,05). Os adesivos testados neste estudo não influenciaram nas cores das "lentes de contato" cimentadas em dentes bovinos com cimento translúcido, imediatamente ou após EAA, porém todos os grupos apresentaram mudança de cor perceptível após o envelhecimento(AU)

The purpose of this study was to evaluate the influence of the adhesive system on the shade of highly translucent ceramic "contact lens" veneers immediately after cementation and after acce-lerated artificial aging (AAA). Forty bovine teeth and 40 ceramic discs (IPS eMax, HT,BL1, 0.5mm thickness) were divided in four experimental groups: GI- Scotchbond Multi-purpose; GII - Single Bond 2; GIII - Single Bond Universal (applied on teeth as adhesive only) and GIV - Single Bond Universal (applied in teeth as adhesive and also on ceramic as a coupling agent). Teeth and ceramic disks were treated prior to cementation with the respective manufacturers' instructions for each experimental group, and the cement used was Variolink Veneer (Value 0). All the specimens were then subjected to 400 hours of AAA. Shade was measured with a spectrophotometer (Easyshade, Vita, Yorba Linda, CA, USA) in three moments: 1) before cementa-tion on the dental substrate, 2) on the cemented disc immediatly after cementation, and 3) after AAA. L*, a*, b*, ΔE1*, and ΔE2* values were submitted to statistical analysis (SPSS 17.0 for Windows) with a significance level of 5% (p<0.05). The tested adhesives in this study did not influence the shade of the non-prep ceramic veneers cemented in bovine teeth with a translucent resin cement, immediately or after AAA, although all groups presented perceptible color change after aging(AU)

Reconhecimento de cores de objetos e de alimentos de cromaticidades opostas por pintos de corte / Recognition of colors of objects and food opposite chromaticities by broiler chicks

Objetivou-se com esta pesquisa avaliar, por meio de testes de preferência, a capacidade de percepção de pintos de corte no reconhecimento de objetos e alimentos de diferentes cores. A pesquisa foi realizada no Brasil e consistiu no condicionamento de 60 pintos de um dia sexados, sendo 30 pintos machos e 30 pintos fêmeas, durante três dias, com esferas azuis e alimento vermelho, cores escolhidas por terem cromaticidades opostas. Após a fase de condicionamento, foi realizado um teste de preferência, no qual os animais eram colocados individualmente no centro de uma arena de teste com quatro opções, sendo elas: alimento vermelho; alimento azul; esferas vermelhas; esferas azuis. Cada ave foi avaliada durante 10 minutos...

The aim of this research was to evaluate, by preference tests, the ability of perception of broiler chicks in the recognition of objects and foods of different colors. The survey was conducted in Brazil and consisted in the conditioning of 60 sexed one-day-old chicks using 30 male chicks and 30 female chicks for three days with blue balls and red food colors chosen for having opposed chromaticities. After the conditioning phase, a preference test was performed, in which the animals were placed individually in the center of an arena test with four options: red food, blue food, red balls and blue balls. Each bird was measured for 10 minutes...

Color dental en diferentes grupos etarios de Pasto, Colombia / Teeth shade in different age groups from Pasto, Colombia

Resumen Introducción y objetivo: La percepción del color de los dientes con instrumentos de coincidencia de sombra visuales es un problema en los procedimientos restauradores estéticos. Los objetivos del presente estudio fueron determinar la prevalencia de color de los dientes y evaluar los factores sociodemográficos, clínicos y comportamentales relacionados con el color dental en diferentes grupos de edad en Pasto, Colombia. Materiales y métodos: Un estudio transversal se llevó a cabo en una muestra probabilística aleatoria de 384 individuos. Se diseñó una encuesta para obtener información sobre las características sociodemográficas, clínicas y comportamentales. El color dental se midió visualmente en los centrales, incisivos y caninos maxilares utilizando los criterios de evaluación de la guía de dientes VITA Master 3D (Vita-Zahnfabrik). Los datos fueron codificados y analizados con el programa SPSS versión 19. Resultados: Las sombras más comunes para los incisivos centrales y los incisivos laterales maxilares fueron 2M2 con 32% y 37,8%, respectivamente, y alrededor de 30% presentaron 2M3 en caninos. La claridad, intensidad y tonalidad cambiaron según la edad. En sujetos del grupo de 45 y =54 hubo una diferencia significativa de acuerdo al sexo en relación con las dimensiones del color. La erosión/ abrasión dental estuvieron significativamente relacionadas con las tres dimensiones de color y fumar con la claridad y tonalidad. Conclusión: Existe una coincidencia de sombra utilizando una guía visual para comparar los patrones de color dental entre diferentes muestras de edades. Las variables demográficas, clínicas y comportamentales se relacionaron significativamente con las dimensiones del color dental.

Abstract Introduction and objective: The perception of teeth color with visual shade matching instruments is a problem in aesthetic restorative procedures. The aims of the present study were to determine the prevalence of teeth color and evaluate the sociodemographic, clinical and behavioral factors related to teeth color in different age groups in Pasto, Colombia. Materials and methods: A cross-sectional study was performed in a random probabilistic sample of 384 individuals. A survey was designed to obtain information about sociodemographic, clinical, and behavioral features. Tooth color was measured visually on the maxillary central incisors, incisives and canines using a VITA tooth guide 3D Master (Vita-Zahnfabrik) evaluation. Data were coded and analyzed using SPSS software version 19. Results: The most common shades for the maxillary central incisors and lateral incisors were 2M2 with 32% and 37.8% respectively and around 30% presented 2M3 for canines. Lightness, chroma and hue varied by age. In subjects group between 45 and ≤54 there was a significant difference according to sex in relation to color dimensions. Dental erosion/abrasion were significantly related to the three dimensions of color and smoking to lightness and hue. Conclusion:There was a shade matching using a visual guide to compare of the dental color patterns among different ages' samples. Demographic, clinical and behavioral variables were significantly related to dental color dimensions.

Influence of the resin cement color on the shade of porcelain veneers after accelerated artificial aging / Influence of the resin cement color on the shade of porcelain veneers after accelerated artificial aging / Influência da cor do cimento resinoso na tonalidade de facetas de porcelana após envelhecimento artificial acelerado

Objectives: The aim of this study was to evaluate the influence of the color of the resin luting cement in the final shade of minimally invasive porcelain veneers after accelerated artificial aging (AAA). Material and methods: 20 bovine teeth were collected, prepared and divided into two groups. The roots were removed and the buccal surfaces were polished to obtain a flat surface. Porcelain discs (IPS Empress Esthetic) were produced to a standardized shade (ET1) and thickness (0.6mm). The teeth and the veneers surfaces were prepared according to manufacturer recommendations. For group I (n=10), the White-Opaque (WO) base-paste was used and for group II (n=10) the Yellow (Y) base-paste. Each specimen was photocured for 60 s. The specimens were next subjected to AAA. They were submitted to color readings with a spectrophotometer in three moments: after the preparation (only the substrate), after the cementation and polymerization of the veneers and after the AAA. Were obtained values of L*, a* and b* and the total color change was calculated (?E*). Values obtained were subjected to statistical analysis in SPSS 17.0 for Windows with a significance of 0.05. Results: When comparing the cements, the Y cement showed higher ?E*, lower L* and higher b* after AAA than the WO. Conclusion: Both cements could mask the substrate color. With AAA, only the Y shade showed a ?E* clinically unacceptable, becoming more yellow (higher b*) and losing lightness (lower L*).

Objetivos: O objetivo do presente estudo foi avaliar a influência da cor do cimento resinoso na tonalidade final de facetas de porcelana minimamente invasivas, após envelhecimento artificial acelerado (EAA). Material e Métodos: 20 dentes bovinos foram coletados, preparados e divididos em dois grupos. As raízes foram removidas e a face vestibular foi polida para obter uma superfície plana. Discos de porcelana (IPS Empress Esthetic) foram confeccionados na cor ET1 e espessura de 0,6 mm. Os dentes e as superfícies dos discos foram preparados de acordo com as recomendações do fabricante. Para o grupo I (n=10) foi usado o cimento resinoso White-Opaque (WO) pasta-base, e para o grupo II (n-10) utilizou-se o Yellow (Y) pasta-base. Cada espécime foi fotopolimerizado por 60 s. Os espécimes foram então submetidos ao EAA. Eles foram submetidos a leituras de cor com auxílio de um espectro fotômetro em três momentos: após o preparo (apenas o substrato), após a cimentação e polimerização das facetas e após o EAA. Foram obtios valores de L*, a* e b* e o total da variação de cor foi calculado (?E*). Os valores obtidos foram submetidos à análise estatística no SPSS 17.0 para Windows, com nível de significância de 0,05. Resultados: O cimento Y apresentou maior ?E*, menor L* e maior b* após o EAA em comparação com o WO. Conclusão: Ambos os cimentos têm capacidade de mascarar a cor do substrato. Com o EAA, apenas o Y apresentou um valor de ?E* inaceitável clinicamente, se tornando mais amarelo (maior b*) e perdendo luminosidade (menor L*).

Color agreement between nanofluorapatite ceramic discs associated with try-in pastes and with resin cements

The aim of this study was to evaluate the in vitro color agreement between nanofluorapatite ceramic discs (e.max Ceram / Ivoclar Vivadent / A2) associated with try-in pastes and those bonded with resin cements (Vitique / DMG/ try-in shade A2½ and cement shade A2½, Variolink II / Ivoclar Vivadent / try-in shade A1 and cement shade A1, and Choice 2 / Bisco / try-in shade A2 and cement shade A2), and to evaluate the shade stability of the discs bonded with resin cements. The shades of composite resin discs (Lliss / FGM / A2) and nanofluorapatite ceramic discs with try-in pastes or cements were evaluated according to the Vita Classical shade guide by a digital spectrophotometer (Micro EspectroShade, MHT) immediately after placing the try-in pastes or resin cements between composite resin discs and ceramic discs. Other evaluations were performed at 2, 5, and 6 day intervals after cementation with the resin cements. All ceramic discs that received try-in pastes presented an A2 shade. There was no statistical difference in the shade of the ceramic specimens fixed with different cements at the different intervals, as evaluated by the Friedman test (p > 0.05). Two try-in pastes presented shade compatibility with those recommended by the manufacturers. There was no similarity of shades between the ceramic discs with try-in pastes and those with the respective resin cements. Shade stability was observed in ceramic discs with resin cements within the intervals evaluated.

CIE L*a*b*: comparison of digital images obtained photographically by manual and automatic modes

The aim of this study was to analyze the color alterations performed by the CIE L*a*b* system in the digital imaging of shade guide tabs, which were obtained photographically according to the automatic and manual modes. This study also sought to examine the observers' agreement in quantifying the coordinates. Four Vita Lumin Vaccum shade guide tabs were used: A3.5, B1, B3 and C4. An EOS Canon digital camera was used to record the digital images of the shade tabs, and the images were processed using Adobe Photoshop software. A total of 80 observations (five replicates of each shade according to two observers in two modes, specifically, automatic and manual) were obtained, leading to color values of L*, a* and b*. The color difference (ΔE) between the modes was calculated and classified as either clinically acceptable or unacceptable. The results indicated that there was agreement between the two observers in obtaining the L*, a* and b* values related to all guides. However, the B1, B3, and C4 shade tabs had ΔE values classified as clinically acceptable (ΔE = 0.44, ΔE = 2.04 and ΔE = 2.69, respectively). The A3.5 shade tab had a ΔE value classified as clinically unacceptable (ΔE = 4.17), as it presented higher values for luminosity in the automatic mode (L* = 54.0) than in the manual mode (L* = 50.6). It was concluded that the B1, B3 and C4 shade tabs can be used at any of the modes in digital camera (manual or automatic), which was a different finding from that observed for the A3.5 shade tab.

Effect of repeated immersion solution cycles on the color stability of denture tooth acrylic resins

OBJECTIVE: Chemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. MATERIAL AND METHODS: Sixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1 percent sodium hypochlorite, 2 percent sodium hypochlorite, 5.25 percent sodium hypochlorite, 2 percent glutaraldehyde, and 4 percent chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5 percent. RESULTS: There were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. CONCLUSIONS: Repeated immersion cycles in disinfecting solutions alter ΔE* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

Color damage in patients with idiopathic optical neuritis after the treatment / 中华眼底病杂志

Objective To detect the color damage in patients with idiopathic optical neuritis (ION) after the treatment. Methods A total of 26 ION patients (44 eyes) with ION whose visual acuity were above 1. 0 were collected. All the patients had undergone the treatment of incretion and had the visual acuity more than 1. 0 after the treatment. The results of MRI and blood examination were normal. Another 24 healthy persons were selected as the normal control. Total error scores (TES) and each error score of red, green and blue were measured via Farnsworth Munsell-100 hue tester. The TES origin scores and their square roots were used for a statistical analysis. The results of the two groups were compared. Results There were significant differences in TES and its square roots between ION group and the normal control group (t=3.079,3. 133;P = 0. 0033,0. 0026). The differences in the level of error scores of each color between the tow groups were not significant (t = 1. 91, 1.15, 1.62;P = 0.061, 0.26, 0.11);but the differences in the square roots of red color between the two groups were statistically (t=2. 21, P = 0. 031).Conclusion After the treatment, the visual acuity of ION patients increases, but the color damage still exist;red color damage happens first.

Associação de alterações cromáticas e uso de anticoncepcionais orais / Association of color vision alterations and the use of oral contraceptives

OBJETIVOS: Avaliar, em mulheres em idade fértil, a associação entre o uso de anticoncepcionais (ACO) orais de baixa dosagem e alterações na visão de cores. MÉTODOS: Foram incluídas no estudo 30 mulheres, 16 usuárias de ACO oral há menos de cinco anos (Grupo I) e 14 usuárias de anticoncepcionais orais há mais de cinco anos (Grupo II). Foram utilizados os testes de Ishihara, City University Color Vision Test e D 15 dessaturado. RESULTADOS: Não foram observados padrões característicos de distúrbio da visão cromática em nenhum teste dos dois grupos. CONCLUSÃO: Na amostra estudada, o uso de ACO oral de baixa dosagem não influenciou a visão de cores, independente do tempo de uso.

PURPOSE: To evaluate the association between oral low-dose contraceptives and color vision alterations. METHODS: Were included in the study 30 women, sixteen used oral contraceptive for less than five years (Group I) and 14 used it for more than five years (Group II). The Ishihara, City University Color Vision Test, and the D 15 desaturated tests were used. RESULTS: No characteristic alterations in the chromatic perception were found in any of the groups. CONCLUSION: In the studied sample, low-dose oral contraceptive has not influenced color vision, independent of the time of use.

Color change using HSB color system of dental resin composites immersed in different common Amazon region beverages

The purpose of this study is to evaluate in vitro the color stability of composite resins when exposed to beverages with high coloring contents from the Amazon region. 240 samples from four different composite brands (Natural Look, Z350, 4Seasons and Opallis) of hue A3 were fabricated using an acrylic matrix. The samples were stored in distilled water at 37ºC for 24 hours. The initial color (T0) was registered using a Canon EOS Rebel XTi 10 mp camera, and then the samples were divided into four groups (n=15): G1 (coffee), G2 (açaí juice), G3 (energetic guaraná) and G4 (control - distilled water). The samples were exposed to solutions of DES (6hs) and RE (18hs) and placed in a double boiler under constant agitation, at 37ºC for 30 days. The samples were immersed in the coloring solutions for 15 minutes daily. After 7, 15 and 30 days, new photographic registers were made (T1, T2 and T3). The images were analyzed using Corel PHOTO-PAINT 12 software to identify the colors through the HSB system. The Kruskal-Wallis and t tests (p 0.05) demonstrated significant differences in color (hue, saturation and brightness). The results revealed that none of the tested composites showed color stability when exposed to coloring solutions, and that the Amazon region beverages (açaí juice and energetic guaraná) showed to be less coloring than coffee.

Este estudo propôs avaliar in vitro a estabilidade de cor de alguns compósitos quando expostos a bebidas da Região Amazônica com alto teor de corante. Foram confeccionados 240 corpos de prova (CP) de quatro resinas (Natural Look, Z350, 4Seasons e Opallis) no matiz A3 utilizando uma matriz de acrílico. As amostras foram armazenadas em água deionizada a 37ºC por 24 horas. A cor inicial das resinas (T0) foi registrada utilizando a máquina Canon EOS Rebel XTi 10Mp, e em seguida os CP foram divididos em 4 grupos (n=15): G1 (café), G2 (suco de açaí), G3 (guaraná energético) e G4 (controle - água destilada). Os CP foram submetidos às soluções DES (6hs) e RE (18hs) e colocados em banho-maria, sob constante agitação, à temperatura de 37ºC durante 30 dias. Diariamente os corpos de prova foram imersos nas soluções corantes durante 15 minutos. Após 7, 15 e 30 dias realizaram-se novos registros fotográficos (T1, T2 e T3). As imagens foram analisadas pelo programa Corel PHOTO-PAINT 12 para a identificação das cores através do sistema HSB. O teste Kruskal-Wallis e teste t (p 0,05) demonstraram que a alteração de cor (matiz, saturação e brilho) indicou diferenças significantes. Foi concluído que nenhuma das resinas testadas apresentou estabilidade de cor quando em contato com as soluções corantes, e que as bebidas da região Amazônica (suco de açaí e guaraná energético) demonstraram ser menos colorantes que o café.