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1.
Braz. j. oral sci ; 21: e222812, jan.-dez. 2022. tab
Article in English | LILACS, BBO | ID: biblio-1348712

ABSTRACT

Aim: To evaluate the influence of the parameters L* a* b* on the variation of the color of bovine tooth enamel submitted to artificial darkening, after simulated brushing, with whitening toothpastes containing blue covarine. Methods: To undertake this study in vitro, 60 specimens (SP) were divided into 6 groups (n=10): control group (CGwater) and 5 test groups (GT1-Colgate Total 12, GT2-Oral-B 3D White Perfection, GT3- Colgate Luminous Instant White, GT4-CloseUp White Diamond Attraction, GT5-Sorriso Xtreme White). The specimens were darkened with coffee and submitted to simulated brushing for 6, 12, and 24 months. The alteration in the color was evaluated using CIELAB parameters and the ΔL, Δa, Δb and ΔE were calculated. The data was analyzed through generalized linear models using the R program and considering a level of significance of 5%. Results: The parameters L*, a* and the ΔL, Δa obtained better results in the test group than in the control group. There were no statistical differences between CG and the test groups for the evaluation of the b* parameter. In the evaluation of the Δb, the GT3 differed statistically from the CG. In relation to the ΔE, all the group tests showed a variation in color statistically greater than that of the CG and the GT4 showed the greatest variation, not differing from the GT3 during the periods studied. Conclusion: The mechanical and optical whitening agents positively influenced the values L*a* and b*, as well as in its variations and in the ΔE. It is important to emphasize, however, that to analyze tooth whitening it is necessary to evaluate their parameters together


Subject(s)
Tooth , Toothpastes , Color , Bleaching Agents
2.
Braz. j. oral sci ; 21: e224265, jan.-dez. 2022. tab
Article in English | LILACS, BBO | ID: biblio-1354719

ABSTRACT

Aim: This study assessed the color and translucency stability of a polymer infiltrated ceramic network (PICN) and compared it with a resin composite (RC) and a feldspathic ceramic (FEL). Methods: Disc-shaped samples of a PICN (Vita Enamic), a feldspathic ceramic (Vitablocks Mark II), and a resin composite (Brava block) were prepared from CAD/CAM blocks. PICN and RC surfaces were finished with a sequence of polishing discs and diamond paste. FEL samples received a glaze layer. The samples were subjected to 30-min immersions in red wine twice a day for 30 days. CIEL*a*b* coordinates were assessed with a spectrophotometer at baseline and after 15 and 30 days of immersion. Color alteration (ΔE00) and translucency parameter (TP00) were calculated with CIEDE2000. Average roughness was measured before the staining procedures. Color difference and translucency data were analyzed with repeated-measures ANOVA and Tukey's tests. Roughness was analyzed with the Kruskal-Wallis test. Results: Roughness was similar among the experimental groups. All materials had their color alteration significantly increased from 15 to 30 days of staining. PICN reached an intermediate ΔE00 between FEL and RC at 15 days. PICN revealed a color alteration as high as the composite after 30 days. No statistical difference was observed regarding translucency. Conclusion: PICN was not as color stable as the feldspathic ceramic at the end of the study. Its color alteration was comparable to the resin composite when exposed to red wine. However, the translucency of the tested materials was stable throughout the 30-day staining


Subject(s)
Surface Properties , Materials Testing , Ceramics , Computer-Aided Design , Color , Composite Resins
3.
Braz. dent. sci ; 25(1): 1-9, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1354722

ABSTRACT

Objective: Elastomeric chains are commonly used to apply force for orthodontic dental movements. However, force decay and discoloration are two important weak points of these materials. The present study intended to compare the force decay and color stability of different types of elastomeric chains. Material and Methods: This in vitro study evaluated 6 groups of elastomeric chains, including thermoplastic (TP) and thermoset (TS) chains made by the companies American Orthodontics (AO), Ormco (OR), and G&H Orthodontics (GH). The elastomeric chain forces were measured at the baseline, following 1 hour, 1 day, 1, 2, 3, 4, 5, and 6 weeks of stretching. The elongation required for the chains to exert a force of 250 g was calculated. ΔE of each group was calculated by a spectrophotometer following immersion in black tea solution for 6 days. Data were analyzed using the SPSS 22 software and the statistical methods of repeated measures analysis of variance and two-way analysis of variance (P<0.05). Results: The force decay of the TS chains were significantly lower than the TP chains in the 6-week study duration (P<0.05), and the lowest and highest force decay was observed in the products by AO and GH, respectively. The highest force degradation occurred during the first week in all groups. The elongation rate needed for the TS chains was significantly higher than the TP chains (P<0.05), and the highest elongation rate was observed in the products by OR. TS chains showed significantly higher color stability than TP chains, and products by OR and GH had better color stability than the products by AO. Conclusion: The present study showed that TS chains were superior to TP chains in force decay and color stability in all the brands studied. (AU)


Objetivo: Elásticos corrente são comumente utilizados para aplicar forças para a movimentação ortodôntica. Porém, a diminuição de força e descoloração são duas importantes fraquezas desses materiais. O presente estudo tem o objetivo de comparar a diminuição de força e estabilidade de cor de diferentes tipos de elásticos corrente. Material e Métodos: Este estudo in vitro avaliou 6 grupos de elásticos corrente, incluindo termoplástico (TP) e termofixo (TS) produzidos pelas empresas American Orthodontics (AO), Ormco (OR) e G&H Orthodontics (GH). A força dos elásticos corrente foram mensuradas no início, após 1 hora, 1 dia, 1, 2, 3, 4, 5 e 6 semanas de alongamento. A força de alongamento necessária para aplicação de 250g foi calculada. O ΔE de cada grupo foi calculado por um espectrofotômetro após a imersão em solução de chá preto por 6 dias. Os dados foram analizados utilizando o programa SPSS 22 e a análise estatística foi realizada por análise de variância e análise de variância dois fatores (p<0,05). Resultados: A diminuição da força do grupo TS foi significativamente menor que o grupo TP em 6 semanas de estudo (p<0,05), e o menor e maior valor de diminuição de força foi observado nos produtos da empresa AO e GH, respectivamente. A maior degradação de força ocorreu durante a primeira semana em todos os grupos. A taxa de alongamento necessária para o grupo TS foi significativamente maior que o grupo TP (p<0,05), e a maior taxa de alongamento foi observada nos produtos da empresa OR. Os elásticos TS obtiveram resultados significativamente maiores de estabilidade de cor que os elásticos TP, e os produtos da OR e GH tiveram melhor estabilidade de cor que oa produtos AO. Conclusão: O presente estudo demonstrou que os elásticos TS foram superiores aos elásticos TP em diminuição de força e estabilidade de cor em todas as marcas estudadas.(AU)


Subject(s)
Tooth Movement Techniques , Color , Elastomers
4.
Psicol. soc. (Online) ; 34: e237658, 2022.
Article in Portuguese | LILACS, INDEXPSI | ID: biblio-1365282

ABSTRACT

Resumo A partir da análise do preenchimento do quesito raça/cor do Cadastro Único para Programas Sociais do Governo Federal (CadÚnico), realizado por entrevistadoras sociais em um Centro de Referência de Assistência Social, este artigo objetiva discutir o tensionamento racial presente no campo da Política Nacional de Assistência Social (PNAS). Assumindo uma política investigativa pautada nos estudos da Ciência, Tecnologia e Sociedade e da Teoria Ator-Rede, utilizamos o registro de diários de campo como ferramenta à produção de dados sobre o referido preenchimento. Nesse percurso, assinalamos que o racismo brasileiro e as ambiguidades ligadas ao quesito raça/cor se atualizam no preenchimento do CadÚnico, implicando diferentes performances à produção da autodeclaração racial. Frente a isso, a compreensão das questões raciais nos processos socioterritoriais e subjetivos, que atravessam os serviços da PNAS, é fundamental ao desenvolvimento de práticas ao exercício da cidadania que não corroborem com manutenção da desigualdade racial brasileira.


Resumen A partir del análisis del llenado de la pregunta raza/color del Registro Único de Programas Sociales del Gobierno Federal (CadÚnico), realizado por entrevistadores sociales en un Centro de Referencia de Asistencia Social, este artículo tiene como objetivo discutir la tensión racial presente en la Política Nacional de Asistencia Social (PNAS). Asumiendo una política de investigación basada en los estudios de Ciencia, Tecnología y Sociedad y la Teoría Actor-Red, utilizamos el registro de diarios de campo como herramienta para la producción de datos sobre dicho relleno. De esta manera, señalamos que el racismo brasileño y las ambigüedades relacionadas con la raza/color se actualizan en el llenado del CadÚnico, lo que implica diferentes actuaciones en la producción de la autodeclaración racial. Así, la comprensión de las cuestiones raciales en los procesos socio-territoriales y subjetivos que atraviesan los servicios del PNAS es fundamental para el desarrollo de prácticas para el ejercicio de la ciudadanía que no corroboren el mantenimiento de la desigualdad racial en Brasil.


Abstract Based on the analysis of the filling out of the race/color question of the Federal Government Registry for the Social Programs (CadÚnico), carried out by social interviewers at a Social Assistance Reference Center, this article aims to discuss the racial tension present in the field of National Social Assistance Policy (PNAS). Assuming an investigative policy based on the studies of Science, Technology and Society and the Actor-Network Theory, we used field diaries registers as a tool for the production of data on the aforementioned filling. We point out that Brazilian racism and the ambiguities related to race/color are updated in filling out the CadÚnico, implying different performances in the production of racial self-declaration. In this view, the understanding of racial issues in the socio-territorial and subjective processes that cross the PNAS services is fundamental to the development of practices for the exercise of citizenship that do not corroborate the maintenance of Brazilian racial inequality.


Subject(s)
Social Work , Color , Social Participation , Racism , Social Programs , Research , Registries
5.
Braz. J. Pharm. Sci. (Online) ; 58: e18946, 2022. tab, graf
Article in English | LILACS | ID: biblio-1364411

ABSTRACT

Abstract To investigate structure-property relationship of polymer-based curcumin solid dispersion (SD), three acrylic polymers were used to formulate curcumin SD by solvent evaporation method. Curcumin Eudragit EPO SD (cur@EPO), curcumin Eudragit RS PO SD (cur@RSPO) and curcumin Eudragit RL PO SD (cur@RLPO) showed deep red, golden orange and reddish orange color, respectively. Cur@RSPO entrapped 15.42 wt% of curcumin followed by cur@RL PO and cur@EPO. FTIR spectra indicated that in cur@EPO, curcumin may transfer hydrogen to the dimethylaminoethyl methacrylate group and thus change its color to red. In contrast, curcumin may form hydrogen bonding with Eudragit RS PO and Eudragit RL. Curcumin exists in amorphous state in three SDs as proved by differential scanning calorimetry and X-Ray diffraction measurement. In vitro digestion presented that lower pH value in simulated gastric fluid (SGF) stimulates the curcumin release from cur@EPO while permeability influences the release profile in other two SDs. When in simulated intestinal fluid (SIF), first order release model governs the release behaviors of all three SDs which showed sustained release pattern. Our results are helpful to elucidate how structure of polymer may impact on the major properties of curcumin contained SD and will be promising to broaden its therapeutic applications.


Subject(s)
Polymers , Curcumin/analysis , Methods , Solvents/administration & dosage , X-Ray Diffraction/instrumentation , In Vitro Techniques/methods , Calorimetry, Differential Scanning/methods , Evaporation/classification , Spectroscopy, Fourier Transform Infrared , Color , Citrus sinensis/classification , Hydrogen-Ion Concentration
6.
Psicol. ciênc. prof ; 42: e235483, 2022. graf
Article in Portuguese | LILACS-Express | LILACS, INDEXPSI | ID: biblio-1360642

ABSTRACT

Resumo A presente produção versa sobre as consequências do racismo na saúde mental das mulheres negras integrantes do Movimento de Mulheres Dandara do Sisal (MMNDS), atuante no Território do Sisal, na Bahia. A intersecção de raça e gênero fomentou a organização do movimento, já que o gênero influi no racismo e a cor, no machismo; além do fato de as mulheres negras serem alvos de racismo e sexismo desde o período da escravização. A abordagem metodológica utilizada foi a descritiva-qualitativa, cujos métodos de coleta de dados foram entrevistas semiestruturadas com seis mulheres negras e observação participante de ações e atividades do movimento Dandara do Sisal. As entrevistadas relataram o racismo, a discriminação e o preconceito raciais que sofreram em suas trajetórias em diferentes espaços e instituições sociais: família, escola, universidade/faculdade, mercado de trabalho, dispositivos de saúde pública etc. Ser vítima de tais violências reflete negativamente na identidade negra, autoestima, subjetividade e saúde mental das atrizes sociais. Elas descreveram o sofrimento psíquico da exclusão social e a importância de estarem em movimento como estratégias de fortalecimento mental e enfrentamento ao racismo. Entende-se a Psicologia, enquanto ciência e profissão, como importante na luta antirracista, pois as consequências deletérias do racismo ameaçam a saúde mental e as subjetividades das mulheres e população negras.(AU)


Abstract This article discusses the consequences of racism on the mental health of black women members of the Dandara of Sisal Black Women Movement (MMNDS), which acts in the territory of Sisal, Bahia. The intersection of race and gender has fostered the movement's creation due to the gender impacting racism and the race affecting the sexism; as well as the fact that black women are victim of racism and sexism since the period of slavery. The methodological approach was qualitative and descriptive, with data collection methods by semi-structured interviews with six black women activists and participant observation of the Dandara of Sisal movement actions and activities. The women reported the racism, racial discrimination and prejudice that they suffered in their lives in different spaces and social institutions: family, school, university, job market, public health mechanisms etc. Being victim of such violence reflects negatively on the black identity, self-esteem, subjectivity, and mental health of these social actresses. They described the psychic suffering of social exclusion and the importance of being in the movement as strategies for mental empowerment and fight against the racism. Psychology is understood, as science and profession, as important in the anti-racist cause, since the deleterious effects of racism threaten the mental health and the subjectivity of black women and people.(AU)


Resumen Este texto se centra en las consecuencias del racismo en la salud mental de las mujeres negras miembros del Movimiento de Mujeres Negras Dandara do Sisal (MMNDS) que actúan en el Territorio do Sisal, en Bahía (Brasil). La intersección entre raza y género ha fomentado la organización del movimiento, ya que el género influye en el racismo, y el color en el machismo, además de que las mujeres negras han sido objeto de racismo y sexismo desde el período de la esclavitud. El enfoque metodológico utilizado fue descriptivo y cualitativo, para la recolección de datos se aplicaron entrevistas semiestructuradas con seis mujeres negras y la observación participante de acciones y actividades del movimiento Dandara do Sisal. Las entrevistadas denunciaron racismo, discriminación y discriminación racial, que sufrieron en sus trayectorias en diferentes espacios e instituciones sociales: familia, escuela, universidad/colegio, mercado laboral, dispositivos de salud pública, etc. Ser víctima de este tipo de violencia refleja negativamente en la identidad negra, la autoestima, la subjetividad y la salud mental de las actrices sociales. Las militantes describieron el sufrimiento psíquico de la exclusión social y la importancia de estar en un colectivo como estrategia para el fortalecimiento mental y la lucha contra el racismo. Se entiende que la Psicología, mientras ciencia y profesión, es importante en la lucha antirracista, ya que las consecuencias nocivas del racismo amenazan la salud mental y las subjetividades de las mujeres negras y la población negra.(AU)


Subject(s)
Humans , Female , Mental Health , African Continental Ancestry Group , Racism , Psychology , Socioeconomic Factors , Violence , Women , Family , Color , Feminism , Sexism , Social Discrimination , Enslavement , Androcentrism , Empowerment
7.
Braz. j. oral sci ; 20: e219320, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253013

ABSTRACT

Aim: This study analyzed the effect of whitening mouth rinses on water sorption (WS), solubility (SL), color change, and surface roughness of a nanofilled composite. Whitening perceptibility and acceptability (WID) were also studied. Methods: Forty specimens of Filtek Z350XT, shade EA2 were produced and randomly distributed (n=8) to AS ­ artificial saliva (control); LWE ­ Listerine Whitening Extreme; CLW ­ Colgate Luminous White; LCM ­ Listerine Cool Mint; and CP ­ Colgate Plax. They were immersed in the mouth rinses 2x/day, for one minute, during 28 days. The color was assessed using an Easyshade spectrophotometer (CIE-L*a*b* system). Surface roughness (Ra-µm) was measured with three parallel measures, using an RP-200 roughness meter. The WS and SL (µg/mm-3) were analyzed based on the ISO 4049 recommendations. The data were analyzed using one- and two-way ANOVA/Tukey tests (α=0.05). Results: Surface roughness significantly increased after immersion in AS and LCM, with no significant differences between the groups either before or after immersion. The ΔE* was not significantly different between the groups. All substances produced a ΔWID higher than the 50%:50% perceptibility and acceptability thresholds. The WS and SL were not significantly affected by the mouth rinses. Conclusion: Whitening mouth rinses did not affect WS, SL, surface roughness, and color stability of a nanofilled composite, regardless of the presence of ethanol in the composition


Subject(s)
Color , Composite Resins , Nonprescription Drugs , Tooth Bleaching Agents , Mouthwashes
8.
Braz. j. oral sci ; 20: e211076, jan.-dez. 2021. tab
Article in English | LILACS, BBO | ID: biblio-1253739

ABSTRACT

Aim: to evaluate the intra and inter-device reliability of two intraoral spectrophotometers in measuring the Commission Internationale de l'Éclairage (CIE) L*a*b* color coordinates and to compare the color difference (ΔE) between both devices. Methods: the central region of the labial surface of the maxillary central incisor of 31 participants was measured twice by each of the devices (VITA EasyShade and Degudent Shadepilot) by one examiner. CIE L*a*b* color coordinates were obtained for all teeth and ΔE was measured and compared. Intraclass correlation coefficient (ICC) and Mann-whitney U test were used to analyze the data (p<0.05). Results: inter-device reliability ICCs in measuring CIE L*a*b* color coordinates ranged between 0.08-0.49 with significant difference between devices only concerning the b coordinate (p<0.05). While intra device reliability ICCs ranged between 0.86-0.89 for VITA EasyShade and 0.81-0.86 for Degudent Shadepilot. The mean ΔE for CIE L*a*b* color coordinates of VITA EasyShade was 3.61 (±1.93) compared to 3.60 (± 1.45) for Degudent Shadepilot with insignificant difference between both devices (p>0.05). Conclusions: high intra device reliability in measuring CIE L*a*b* color coordinates was achieved particularly of Vita EasyShade, and both devices had clinically acceptable color difference (ΔE <3.7) however, inter device reliability was low to moderate. Consequently, the same spectrophotometer should be used throughout the steps of performing any tooth- colored restoration


Subject(s)
Humans , Male , Adult , Spectrophotometry , Color , Data Accuracy
9.
Rev. Odontol. Araçatuba (Impr.) ; 42(2): 18-23, maio-ago. 2021. tab
Article in Portuguese | LILACS, BBO | ID: biblio-1252902

ABSTRACT

O objetivo do estudo foi realizar uma revisão narrativa da literatura para comparar os métodos visual e instrumental de seleção da cor dentária, correlacionando-os com o fator experiência e a educação continuada. Utilizou-se como base de dados a MEDLINE na qual foram aplicados os descritores "visualshade match", "color measurement", "spectrophotometer" e "tooth color determination". Os critérios de inclusão foram artigos publicados entre 2010 e 2020que abordassem uma análise comparativa entre as duas modalidades de seleção da cor dentária. Se enquadraram nos critérios de exclusão estudos que não contemplavam a temática abordada e aqueles publicados nos anos anteriores a 2010, além das revisões de literatura. No total, onze artigos foram selecionados para compor essa revisão. Os estudos demonstraram que o método instrumental apresentou maior confiabilidade e reprodutibilidade quando comparado ao método visual, isso se deve ao fato de a escolha de cor através de instrumentos eletrônicos proporcionar melhor precisão e atenuação da subjetividade. No que concerne a experiência como fator influenciador da seleção de cor, os estudos são controversos. Mesmo evidenciando melhor precisão, a estimativa instrumental apresenta limitações devido à dificuldade de aferição em função da convexidade da anatomia dentária. Desse modo, foi descrito que a associação de métodos é capaz de elevar a confiabilidade da escolha de cor, melhorando o resultado estético. Não houve consenso entre os estudos com relação à influência da experiência, no entanto, a educação continuada foi sugerida na literatura como alternativa para formar profissionais mais confiantes no processo de seleção de tonalidades(AU)


The goal of this study was to carry out a narrative review of the literature to compare the visual and instrumental methods of tooth color selection, correlating them with the experience factor and continuing education. MEDLINE was used as a database in which the descriptions such as "visual shade match", "color measurement", "spectrophotometer" and "tooth color determination" were applied. The inclusion criteria were articles published between 2010 and 2020 that addressed a comparative analysis between the two types of tooth color selection. The exclusion criteria included studies that did not contemplate the theme addressed and those published in the years prior to 2010, in addition to literature reviews. In total, eleven articles were selected to compose this review. Studies have shown that the instrumental method showed greater reliability and reproducibility when compared to the visual method, this is due to the fact that the color's choice through electronic instruments provides better precision and lessened subjectivity. Regarding experience as na influencing factor in color selection, studies are controversial. Even with better precision, the instrumental estimation has limitations due to the difficulty of measuring it due to the convexity of the dental anatomy. Thus, it was described that the association of the methods is able to increase the reliability of the color's choice, improving the aesthetic result. There was no consensus among the studies in regard to the experiment's influence, however, continuing education was suggested in the literature as an alternative in order to form more confident professionals when it comes to the shade selection process(AU)


Subject(s)
Color , Esthetics, Dental , Spectrophotometry
10.
Braz. dent. j ; 32(4): 19-30, July-Aug. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1345519

ABSTRACT

Abstract: This study investigated the bleaching effectiveness and the physicochemical effects on enamel of violet light and ozone, associate or not to hydrogen peroxide, compared to 35%-hydrogen peroxide. Enamel-dentin blocks from human molars were randomly allocated to receive one of the following bleaching protocols (n=15): (HP) 35%-hydrogen peroxide, (VL) violet light, (OZ) ozone, the association between hydrogen peroxide with ozone (OZ+HP) or violet light (VL+HP). All protocols were performed in two sessions with a 48h interval. Color (spectrophotometer) and mineral composition (Raman spectroscopy) were measured before and after the bleaching. Color changes were calculated by ΔEab, ΔE00, and whitening index (WI). The surface roughness was measured with an atomic force microscope. Data were analyzed by One-way or Two-way repeated measure ANOVA followed by the Tukey's test (α = 0.05). The lowest color change values (either measured by WI, ΔEab, or ΔE00) were observed for VL and OZ used with no HP. Violet light associate with HP was unable to improve the color changes observed for the peroxide alone, in combination with OZ and HP, the highest color changes were verified. Regardless of bleaching protocol, the bleached enamel presented higher contents of PO4 and CO3 -2 than those observed at baseline. All bleaching protocols resulted in similar enamel surface roughness. Both the VL and the OZ caused reduced effects on the enamel color change when used alone. The ozone therapy improved the bleaching effect in the group that received the association of HP.


Resumo O objetivo deste estudo foi avaliar o efeito clareador e físico-químico no esmalte de luz violeta e ozônio, associado ou não ao peróxido de hidrogênio, comparado a 35% de peróxido de hidrogênio. Blocos de esmalte-dentina de molares humanos foram alocados aleatoriamente para receber um dos seguintes protocolos de clareamento (n = 15): (HP) peróxido de hidrogênio a 35%, (VL) luz violeta, (OZ) ozônio, a associação entre peróxido de hidrogênio com ozônio (HP+OZ) ou luz violeta (HP+VL). Todos os protocolos foram realizados em duas sessões, com intervalo de 48 horas entre eles. A cor (espectrofotômetro) e a composição mineral (espectroscopia Raman) do dente foram medidas antes e após os procedimentos de clareamento. As alterações de cor foram calculadas por ΔEab e ΔE00, e o índice de brancura foram calculados. A rugosidade da superfície das amostras clareadas foi medida por microscópio de força atômica. Os dados foram analisados por ANOVA One way ou ANOVA two way de medidas repetidas seguida pelo teste de Tukey (α = 0,05). Os menores valores de alterações de cor (medidos por WI, ΔEab ou ΔE00) foram observados para VL e OZ usados na ausência de HP. VL associada ao HP não foi capaz de melhorar as alterações de cor observadas com o uso do HP, mas a combinação de OZ e HP produz as maiores alterações de cor. Independentemente do protocolo de clareamento, o esmalte clareado apresentou maiores teores de PO4 e CO3 -2 do que os observados inicialmente. Não foi observada diferença significativa entre os protocolos de clareamento testados em relação à rugosidade da superfície do esmalte. É possível concluir que a VL ou o OZ tiveram efeitos reduzidos na mudança de cor do esmalte quando usados sozinhos. A terapia com OZ melhorou o efeito clareador do HP.


Subject(s)
Humans , Ozone , Tooth Bleaching , Tooth Bleaching Agents , Color , Dental Enamel , Hydrogen Peroxide
11.
RECIIS (Online) ; 15(2): 294-300, abr.-jun. 2021. ilus
Article in Portuguese | LILACS | ID: biblio-1254582

ABSTRACT

Esta nota discute a ausência dos quesitos cor/raça e gênero nos boletins epidemiológicos da Covid-19 e como essa omissão está articulada ao modo como se operacionaliza o racismo no Brasil. Coloca-se em evidência a apropriação da identidade racial e de gênero por alguns estados brasileiros que ganharam visibilidade midiática, como sendo solidários, ao iniciarem a campanha de vacinação com mulheres negras, grupo social mais vulnerável. É o jogo da dissimulação, em que se evidencia a raça/gênero na aparência, embora essas variáveis não sejam consideradas no enfrentamento da pandemia.


This note discusses the non-inclusion of information about color/race and gender in Covid-19 epidemiological reports and how this omission is related to the way that the racism is operated in Brazil. It highlights the racial and gender identity appropriation by some Brazilian states, which have gained media visibility as sympathetic governments to Black women, by starting the vaccination campaign with them, an extremely vulnerable social group. It is like a confidence trick, in which race and gender are in the spotlight, although these features are not considered in the fight against the pandemic.


Esta nota discute la ausencia de las informaciones sobre cor/raza y género en los boletines epidemiológicos de la Covid-19 y como esa omisión se encuentra articulada al modo en que se opera el racismo en Brasil. Destaca la apropiación de la identidad racial y de género por parte de algunos estados brasileños que han ganado visibilidad mediática, vistos como solidarios, puesto que han iniciado la campaña de vacunación con algunas mujeres negras, el grupo social más vulnerable. Es el juego del disimulo, por lo cual es evidenciada la raza/género en la apariencia, sin embargo esas variables no sean tenidas en cuenta en el enfrentamiento a la pandemia.


Subject(s)
Humans , Socioeconomic Factors , Color , Coronavirus Infections , Racism , Gender Identity , Brazil , Direct-to-Consumer Advertising , Health of Ethnic Minorities
12.
Av. psicol. latinoam ; 39(1): 1-9, ene.-abr. 2021. ilus, graf
Article in Portuguese | LILACS, COLNAL | ID: biblio-1367003

ABSTRACT

O papel da localização na integração das características visuais na memória é controverso. Algumas evidências sugerem que a localização perde importância logo depois da consolidação da informação, outras, que a localização permanece associada à representação do objeto por mais tempo. Nós investigamos o papel da localização para a memória de objetos definidos por cor e forma. Os participantes (36) realizaram uma tarefa de detecção de mudança com 3 e 6 estímulos, com dois intervalos de retenção (500 e 1.500 milis-segundos). O desempenho é melhor quando a carga é menor, quando os estímulos são apresentados nos mesmos lugares em que foram memorizados, e depen-de da interação entre estes fatores. O intervalo de retenção não interfere no efeito da localização, mas modula o efeito da carga. Estes resultados sugerem que a localização é codificada de forma incidental com os estímulos visuais e que esta associação permanece inalterada dentro dos limites de tempo investigados.


El papel de la localización en la integración de las características visuales en la memoria es controverti-do. Algunas evidencias sugieren que la localización pierde importancia poco después de la consolida-ción de la información, otras, que la localización per-manece asociada a la representación del objeto durante más tiempo. Investigamos el papel de la localización para la memoria de los objetos definidos por el color y la forma. Los 36 participantes realizaron una tarea de detección de cambios con 3 y 6 estímulos, con dos intervalos de retención (500 y 1.500 milisegundos). El rendimiento es mejor cuando la carga es menor, cuando los estímulos se presentan en los mismos lugares donde fueron memorizados, y depende de la interacción entre estos factores. El intervalo de retención no interfiere con el efecto de ubicación, pero modula el efecto de carga. Estos resultados sugieren que la ubicación se codifica incidentalmente con estímulos visuales y que esta asociación permanece sin cambios dentro de los límites de tiempo investigados


The role of localization in the integration of visual char-acteristics into memory is controversial. Some evidence suggests that location loses importance soon after the consolidation of information; others, that the location remains associated with the representation of the object for longer. We investigated the role of location for the memory of objects defined by color and shape. Partici-pants (36) performed a change detection task with 3 and 6 stimuli, with two retention intervals (500 and 1. 500 milliseconds). Performance is better when the load is lower, stimuli are presented in the same places where they were memorized, and it depends on the interaction between these factors. The retention interval does not interfere with the location effect but modulates that of the load. These results suggest that localization is incidental-ly encoded with visual stimuli and that this association remains unchanged within the time limits investigated.


Subject(s)
Humans , Adult , Memory , Photic Stimulation , Vision, Ocular , Data Interpretation, Statistical , Color , Information
13.
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
14.
Braz. dent. j ; 32(1): 78-84, Jan.-Feb. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1180726

ABSTRACT

Abstract The objective of this study was to evaluate the effect of the exposure reciprocity law of a multi-wave light-emitting diode (LED) on the light transmittance (LT), depth of cure (DOC) and degree of conversion in-depth (DC) of a bulk fill composite. A bulk fill composite (EvoCeram® bulk fill, Ivoclar Vivadent) was photoactivated using the multi-wave LED (VALO™ Cordless, Ultradent). The LED was previously characterized using a spectrophotometer to standardize the time of exposure when using the Standard or Xtra-Power modes with the same radiant exposure of 20J/cm2. LT was evaluated through samples of the bulk fill composite every millimeter till 4 mm in-depth. DOC was evaluated according to the ISO 4049. DC of the central longitudinal cross-section from each sample of the DOC test was mapped using FT-NIR microscopy. Data were statistically analyzed according to the experimental design (α=0.05; ß=0.2). The radiant exposure in the violet wavelength range for Standard and Xtra-Power was 4.5 and 5.0 J/cm2, respectively; for the blue wavelength range the radiant exposure for Standard and Xtra-Power was 15.5 and 15.0 J/cm2, respectively. There was no statistical difference in the DOC using Standard or Xtra-Power light-curing modes, but the DOC was lower than the claimed by the manufacturer (4 mm). The DC was not significantly affected by the light-curing mode up to 4 mm in depth (p>0.05). According to exposure reciprocity law, the reduction in exposure time using the same radiant exposure did not affect the depth of cure of the bulk fill composite.


Resumo O objetivo deste estudo foi avaliar o efeito da lei de reciprocidade de um diodo emissor de luz (LED) multi-wave na transmitância de luz (LT), profundidade de cura (DOC) e grau de conversão em profundidade (DC) de um compósito bulk fill. Material e Métodos: Um compósito bulk fill (EvoCeram®, Ivoclar Vivadent) foi fotoativado utilizando um LED multi-wave (VALO ™ Cordless, Ultradent). O LED foi previamente caracterizado usando um espectrofotômetro para padronizar o tempo de exposição utilizando os modos Standard ou Xtra-Power com a mesma dose de energia de 20 J/cm 2. A LT foi avaliada através de amostras do compósito bulk fill a cada milímetro até 4 mm de profundidade. O DOC foi avaliado de acordo com a ISO 4049. O DC foi realizado em forma de mapeamento da seção transversal longitudinal central de cada amostra do teste de DOC utilizando microscopia FT-NIR. Os dados foram analisados estatisticamente de acordo com o delineamento experimental (α=0,05; ß=0,2). A exposição radiante na faixa de comprimento de onda violeta para os modos Standard e Xtra-Power foi de 4,5 e 5,0 J/cm2, respectivamente; e para a faixa de comprimento de onda azul, a exposição radiante para os modos Standard e Xtra-Power foi de 15,5 e 15,0 J/cm2, respectivamente. Não houve diferença estatística no DOC utilizando os modos de fotopolimerização Standard ou Xtra-Power, mas o DOC foi menor do que o reivindicado pelo fabricante (4 mm). O DC não foi afetado significativamente pelo modo de fotopolimerização até 4 mm de profundidade (p>0,05). De acordo com a lei de reciprocidade da exposição, a redução no tempo de exposição utilizando a mesma exposição radiante não afetou a profundidade de cura do compósito bulk fill.


Subject(s)
Composite Resins , Curing Lights, Dental , Surface Properties , Materials Testing , Color , Light-Curing of Dental Adhesives , Polymerization , Hardness
15.
Braz. dent. j ; 32(1): 91-97, Jan.-Feb. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1180719

ABSTRACT

Abstract This study investigated the effects of oxygen inhibition and finishing/polishing procedures on the composite resin properties. One bulk-fill and two conventional composite resins (nanoparticle and microhybrid) were evaluated. Specimens were prepared using 4 surface treatments: control, no treatment; Gly, oxygen inhibition with glycerin; FP, finishing and polishing; Gly + FP, glycerin followed by finishing and polishing. The degree of conversion (DC) was measured using Fourier Transformed Infrared Spectroscopy (FTIR) immediately and after 15 days (n=5). Color stability (ΔEab, and ΔE00) and opacity were evaluated using a spectrophotometer after 15 days of immersion in coffee, using the CIELAB system (n=5). Data were analyzed by two-way ANOVA and Tukey tests (α=0.05) and opacity by two-way repeated-measures ANOVA. Glycerin usage increased significantly the DC however had no influence on the ΔEab, ΔE00 and, opacity values. Finishing and polishing reduced ΔEab and ΔE00 values, regardless of composite resins. Microhybrid showed higher opacity, followed by the nanoparticle and bulk fill, regardless of surface treatment. Post-polymerization polishing procedures resulted in lower conversion than using an oxygen inhibitor agent (Gly condition), but similar staining caused by coffee.


Resumo Este estudo investigou os efeitos da inibição de oxigênio e dos procedimentos de acabamento/polimento nas propriedades das resinas compostas. Foram avaliadas uma resina composta bulk fill e duas resinas convencionais (nanoparticulada e microhíbrida). Os espécimes foram confeccionados, variando o tratamento de superfície: controle, sem tratamento; glicerina (inibidor de oxigênio); acabamento e polimento; glicerina + acabamento e polimento. O grau de conversão (GC) foi medido pela Espectroscopia de Infravermelho Transformada de Fourier (FTIR) imediatamente e após 15 dias da confecção dos espécimes (n=5). Os índices de alteração de cor ΔEab, ΔE00 e opacidade foram avaliados por meio de espectrofotômetro, após 15 dias de imersão no café, utilizando o sistema CIELAB (n=5). Os dados da alteração da cor foram analisados pelos testes ANOVA de dois fatores e Tukey (α=0,05) e a opacidade por ANOVA de medidas repetidas. O uso de glicerina aumentou significativamente o GC, no entanto, não teve influência sobre os valores ΔEab e ΔE00. O acabamento e o polimento reduziram os valores de ΔEab e ΔE00, independentemente da resina composta. A resina microhíbrida apresentou maior opacidade, seguida pela nanoparticula e bulk-fill, independentemente do tratamento de superfície. O acabamento e polimento resultou em menor grau de conversão das resinas compostas se comparado ao uso de um agente inibidor de oxigênio (glicerina), porém apresenta resultados similares para a pigmentação pelo café.


Subject(s)
Oxygen , Composite Resins , Surface Properties , Materials Testing , Color , Dental Materials , Dental Polishing
16.
Article in Chinese | WPRIM | ID: wpr-879044

ABSTRACT

L~*, a~* and b~* values of prepared slices of Curcumae Rhizoma were measured by spectrophotometer. SPSS 21.0 was used for discriminant analysis to establish the color range and mathematical prediction model of prepared slices of Curcumae Rhizoma. The values of L~*, a~* and b~* of kwangsiensis ranged from 58.09-62.40, 4.53-5.66 and 23.61-24.29, while the values of L~*, a~* and b~* of phaeocaulis were between 64.02-70.71,-0.89-4.13 and 44.59-54.52, respectively. The values of L~*, a~* and b~* of wenyujin were 68.55-70.99,-0.11-1.47 and 28.26-32.19, respectively. The mathematical prediction model was proved to be able to realize 100% identification of Curcumae Rhizome of different origins through original and cross validation and external samples validation. A dual wavelength HPLC was established; the contents of 9 sesquiterpenoids and 3 Curcumae Rhizomes were determined simultaneously; and the contents of Curcumae Rhizome of different origins were determined. The results showed that kwangsiensis had higher contents of neocurdione, β-elemene and isocurcumaenol, phaeocaulis curcumin, furadienone, demethoxycurcumin and curcumin; and wenyujin mainly contained curdione, furadienes and guimarone. Pearson correlation analysis on L~*, a~*, b~* value and content of 12 components showed that curcumin, furadienone, demethoxycurcumin and curcumin had a significant positive correlation with b~* value(P<0.01). There was a significant negative correlation between neocurdione, β-elemene and isocurcumaenol and L~* value(P<0.01). Curdione, furadienes and guimarone were significantly correlated with L~* value(P<0.01),indicating that the appearance co-lor of Curcumae Rhizoma could reflect the change of the content of the internal components. This study provided reference for the rapid recognition of Curcumae Rhizoma and the establishment of quality evaluation system.


Subject(s)
Chromatography, High Pressure Liquid , Color , Curcuma , Curcumin , Rhizome
17.
Chinese Journal of Biotechnology ; (12): 1312-1323, 2021.
Article in Chinese | WPRIM | ID: wpr-878633

ABSTRACT

Dihydroflavanol-4-reductase (Dfr) is a key enzyme that regulates the synthesis of anthocyanin and proanthocyanidin in the flavonoid biosynthesis pathway. To investigate the difference of dfr gene in Scutellaria baicalensis Georgi with different colors in the same ecological environment, three complete full-length sequences of dfr gene were cloned from the cDNA of S. baicalensis with white, purple-red and purple colors using homologous cloning and RACE techniques. The three genes were named Sbdfr1, Sbdfr2 and Sbdfr3, respectively, and their corresponding structures were analyzed. The results showed that all three Dfr proteins have highly conserved NADPH binding sites and substrate-specific binding sites. Phylogenetic analysis showed that they are closely related to that of the known S. viscidula (ACV49882.1). Analysis of key structural domains and 3D models revealed differences in the catalytically active regions on the surface of all three Dfr proteins, and their unique structural characteristics may provide favorable conditions for studying the substrate specificity of different Dfr proteins. qRT-PCR analysis shows that dfr was expressed at different level in all tissues except the roots of S. baicalensis in full-bloom. During floral development, the expression level of dfr in white and purple-flowered Scutellaria showed an overall upward trend. In purple-red-flowered Scutellaria, the expression first slowly increased, followed by a decrease, and then rapidly increased to the maximum. This research provides a theoretical basis for further exploring the mechanism and function of Dfr substrate selectivity, and are of great scientific value for elucidating the molecular mechanism of floral color variation in S. baicalensis.


Subject(s)
Anthocyanins , Cloning, Molecular , Color , Phylogeny , Scutellaria baicalensis/genetics
18.
Article in English | WPRIM | ID: wpr-878453

ABSTRACT

OBJECTIVES@#To analyze the chromatic properties and translucency of porcelain veneers made from different ceramic materials against the background of tetracycline-stained teeth.@*METHODS@#Porcelain specimens (A1, A3, B2, B4) measuring 0.50 mm in thickness were prepared by heat-press casting and layering. The L*, a*, and b* values of the specimens against simulated tetracycline tooth and black-and-white backgrounds were measured by a spectrophotometer, and color differences ΔE@*RESULTS@#The ΔE@*CONCLUSIONS@#When changing the color of tetracycline-stained teeth, 0.50 mm-thick IPS d.SIGN feldspathic veneers with an opaque layer provide better chromatic properties than IPS e.max Press LT glass ceramic veneers. However, the translucency of feldspathic veneers is generally poorer than that of glass ceramic veneers.


Subject(s)
Ceramics , Color , Dental Porcelain , Dental Veneers , Materials Testing , Tetracyclines
19.
Article in English | WPRIM | ID: wpr-878452

ABSTRACT

OBJECTIVES@#This study aimed to evaluate the color stability of tetracycline teeth restored with ceramic veneers of different thicknesses combined with different resin cement systems after aging.@*METHODS@#Twenty patients with tetracycline teeth, including two maxillary central incisors, were selected clinically. The patients were randomly divided into four groups and restored with 0.5 and 0.75 mm ceramic veneers by using a veneer adhesive system, either with light-cured or dual-cured reaction. The color difference (ΔE) values after cementation and 1, 6, 12, and 24 months of use were obtained by quantification of L*, a*, and b* values with a colorimeter. The results were analyzed statistically with two-way ANOVA and Student's @*RESULTS@#The ΔE values of ceramic veneers detected after aging were less than 2.25. The 0.5 mm groups exhibited greater color change than the 0.75 mm-thick veneers (@*CONCLUSIONS@#Resin cements and veneer thickness influence the color of ceramic veneers after aging. Cementation of veneers with either dual- or light-cured resin cements does not affect the long-term color stability of tetracycline teeth differently.


Subject(s)
Ceramics , Color , Dental Porcelain , Dental Veneers , Humans , Materials Testing , Resin Cements , Tetracyclines
20.
Braz. dent. sci ; 24(1): 1-7, 2021. tab
Article in English | LILACS, BBO | ID: biblio-1145514

ABSTRACT

Objective: The aim of this in vitro study was to evaluate the color stability of different bulk fill composite resins after extrinsic staining with coffee. Material and Methods: Forty-eight disk-shaped specimens (6 mm diameter x 4 mm thick) of each composite resin were prepared for color change test. The composite resins were divided into 4 groups (n=12): one conventional composite resin (Filtek Z250) and three bulk-fill composite resins (Filtek Bulk Fill, Aura Bulk Fill, and Opus Bulk Fill). The samples were stained with 20 mL coffee solution for 7 days, with the solution being replaced every 24 h. The color change analysis was performed using a spectrophotometer, according to the CIE Lab formula. Data were analyzed using the Analysis of variance (ANOVA) and Tukey HSD tests (α=0.05). Results: The results revealed significant differences in color change among the composite resins tested (ρ<0.0001). The Aura Bulk Fill and Opus Bulk Fill showed the highest color change values. Conclusion:Thus, all the resins analyzed were susceptible to extrinsic staining with coffee, and the Filtek Bulk Fill showed the lowest color change value (AU)


Objetivo: O objetivo deste estudo in vitro foi avaliar a estabilidade da cor de diferentes resinas compostas bulk fill após coloração extrínseca com café. Material e Métodos: 48 corpos-de-prova em forma de disco (6 mm de diâmetro x 4 mm de espessura) de cada resina composta foram preparados para o teste de alteração de cor. As resinas compostas foram divididas em 4 grupos (n = 12): uma resina composta convencional (Filtek Z250) e três resinas compostas bulk-fill (Filtek Bulk Fill, Aura Bulk Fill e Opus Bulk Fill). As amostras foram coradas com 20 mL de solução de café por 7 dias, sendo a solução substituída a cada 24 horas. A análise da mudança de cor foi realizada em espectrofotômetro, de acordo com a fórmula CIE Lab. Os dados foram analisados por meio dos testes de Análise de Variância (ANOVA) e Tukey HSD (α = 0,05). Resultados: Os resultados revelaram diferenças significativas na mudança de cor entre as resinas compostas testadas (ρ <0,0001). A Aura Bulk Fill e a Opus Bulk Fill apresentaram os maiores valores de alteração de cor. Conclusão: Assim, todas as resinas analisadas foram suscetíveis à coloração extrínseca com café, sendo que a Filtek Bulk Fill apresentou o menor valor de alteração de cor. (AU)


Subject(s)
Analysis of Variance , Coffee , Color , Composite Resins , Dentistry
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