Color variation of composite resins in relation to the Vita Classical shade guide: colorimetric analysis

Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection

Analysis of color stability and degree of conversion of different types of resin composites

Abstract Resin composites containing surface pre-reacted glass (S-PRG) have been introduced to reduce demineralization and improve remineralization of the tooth structure. However, water diffusion within the material is necessary for its action, which can impair its overall physicomechanical properties over time, including color stability. This study aimed to evaluate the color stability and related degree of conversion (DC) of four resin composites. Discs (6 x 4 mm, n = 5/group) of microhybrid (MH), nanofilled (NF), nanohybrid (NH), and S-PRG-based nanohybrid (S-PRG-NH) composites with two opacities (A2/A2E and A2O/A2D) were prepared. Color (CIELab and CIEDE2000) was evaluated with a spectrophotometer after aging in grape juice (2 x 10 min/10mL/7days). The DC was analyzed by using Fourier transform infrared spectroscopy before and after light-curing. Data were statistically analyzed by using two-way analysis of variance and post-hoc least significant difference tests (p<0.05). In the color stability analysis, the interaction between filler type and opacity was significant (CIELab, p = 0.0015; CIEDE2000, p = 0.0026). NH presented the highest color stability, which did not differ from that of MH. The greatest color alteration was observed for S-PRG-NH. S-PRG fillers also influenced DC (p < 0.05). The nanohybrid resin composite presented favorable overall performance, which is likely related to its more stable organic content. Notwithstanding the benefits of using S-PRG-based nanohybrid resins, mostly in aesthetic procedures, professionals should consider the susceptibility of such resins to color alteration, probably due to the water-based bioactive mechanism of action.

Color matching and color recovery in large composite restorations using single-shade or universal composites

Abstract This study assessed the color-matching ability and color recovery of unprepared teeth when using single-shade composites and a universal composite in large restorations. Buccal and palatine surface colors of molars were measured with a spectrophotometer (CIELAB) before preparing round cavities (6 mm in diameter, 2 mm in depth). The cavities were randomly filled with a single-shade composite (Omnichroma, Diamond One, or Vittra APS Unique) or a universal composite (Filtek Universal). Color measurements of the restored cavities were taken, and overall color differences (ΔEab and ΔE00) and differences in the whitening index for dentistry (ΔWID) from baseline were calculated. Additionally, visual assessments of a color match to the surrounding enamel were performed by forty evaluators (laypersons and undergraduate students of dentistry) in a viewing booth under illuminant D65, with rating scores from 0 (no color mismatch) to 4 (not acceptable). Data were analyzed using RM or one-way ANOVA (α = 0.05). Results showed that the restorations generally exhibited whiter colors (WID ranged from 27.9 to 41.3) than the unprepared teeth (WID ranged from 15.9 to 19.3). The composite Filtek Universal demonstrated the lowest color discrepancy (ΔWID = 8.6; ΔE00 = 10.8; and ΔE00 = 6.2), and no significant differences were observed among the evaluated single-shade composites. Furthermore, all composites showed similar and adequate color matches to the surrounding enamel. However, it is important to note that despite their ability to match the surrounding enamel reasonably, none of the composites evaluated in large restorations fully recovered the color observed in unprepared teeth.

Resumo Este estudo avaliou a habilidade de combinação de cores e recuperação de cor de dentes não preparados ao utilizar resinas compostas de única tonalidade e uma resina composta universal em grandes restaurações. As cores das superfícies bucais e palatinas de molares foram medidas com um espectrofotômetro (CIELAB) antes de preparar cavidades esféricas (6 mm de diâmetro, 2 mm de profundidade). As cavidades foram preenchidas aleatoriamente com uma resina composta de única tonalidade (Omnichroma, Diamond One ou Vittra APS Unique) ou com uma resina composta universal (Filtek Universal). Foram realizadas medições das cores das cavidades restauradas e calculadas as diferenças de cor globais (ΔEab and ΔE00)) e as diferenças no índice de clareamento para odontologia (ΔWID) em relação à cor inicial. Além disso, foram realizadas avaliações visuais da correspondência de cor com o esmalte circundante por quarenta avaliadores (leigos e estudantes de odontologia) em uma cabine de visualização sob iluminante D65, com pontuações de 0 (nenhuma discrepância de cor) a 4 (não aceitável). Os dados foram analisados usando RM ou ANOVA unidirecional (α = 0,05). Os resultados mostraram que as restaurações geralmente apresentavam cores mais brancas (WID variou de 27,9 a 41,3) do que os dentes não preparados (WID variou de 15,9 a 19,3). A resina composta Filtek Universal demonstrou a menor discrepância de cor (ΔWID = 8,6; ΔE00 = 10,8; and ΔE00 = 6,2), e não foram observadas diferenças significativas entre as resinas compostas de única tonalidade avaliadas. Além disso, todas as resinas compostas apresentaram correspondência de cor similar e adequada com o esmalte circundante. No entanto, é importante observar que, apesar de sua capacidade de corresponder razoavelmente com o esmalte circundante, nenhuma das resinas compostas avaliadas em grandes restaurações recuperou completamente a cor observada nos dentes não preparados.

Influence of repositioning guides' color and usage on precision in tooth color measurement with a clinical spectrophotometer

Abstract Repositioning guides are commonly employed in clinical studies to ensure consistent tooth color measurements. Yet, their influence on measured color remains uncertain. Objective This study evaluated the impact of repositioning guides' color and usage on tooth color measurement using a clinical spectrophotometer. Methodology In total, 18 volunteers participated in this study, in which the color of their upper left central incisor and upper left canine was measured with or without repositioning guides (control). The guides were made from pink, blue, or translucent silicone, as well as an acetate-based bleaching tray. Tooth color was measured in triplicates using a clinical spectrophotometer based on the CIELAB system. The standard deviations of these readings were used to estimate reproducibility, and color differences (ΔE00) between the measurements with guides and the control were calculated. Results Repositioning guides had a minimal effect on L* values and no effect on b* values. The use of pink silicone increased a* values, whereas blue or translucent silicone reduced them. Irrespective of the evaluated tooth, the lowest ΔE00 values were observed for the translucent silicone and bleaching tray. The usage of guides only affected data variability for the L* color coordinate. Conclusion Using repositioning guides can significantly impact the precision of tooth color measurement with a clinical spectrophotometer.

Effect of Toothpaste Fluoride Concentration on Color Stability of Resin Composites: An In Vitro Study

ABSTRACT Objective: To investigate the effects of two different dentifrice fluoride concentrations on the color stability of the composite. Material and Methods: Twenty-seven specimens (2×4×5 mm) each of microfilled (Gradia, GC, Japan) and nanohybrid (Grandio, VOCO, Germany) composites were prepared. The specimens were randomly divided into six groups (control, Fluoflor caries protection toothpaste with 1450ppm Fluoride (EXW, France), and Fluoflor kids toothpaste with 500ppm Fluoride (EXW, France) (n = 9). The specimens were immersed in a mixture of artificial saliva and toothpaste in a ratio of 1:3 and applied for 60 seconds every 12 hours for 42 days. The control samples were incubated in artificial saliva at 37°C. Primary and secondary color measurements were performed using color parameters (L∗a∗b) with a spectrophotoshade (MHT Optic Research AG, Niederhasli, Switzerland). Data were analyzed using a two-way analysis of variance at a significance level of 0.05. Results: According to the two-way ANOVA analysis, there was no significant difference in color change between the composites and no difference in the level of discoloration between different fluoride concentrations(p>0.05). Also, None of the dentifrices caused clinically significant color changes(∆E˂3.3). Conclusion: No clinically unacceptable color changes were observed in the microfilled and nanofilled composites with different concentrations of fluoride toothpaste.

Comparison of Quality Change During Processing Process of Achyranthis Bidentatae Radix from Different Origins Based on Color-component Correlation Analysis / 中国实验方剂学杂志

ObjectiveTaking Achyranthis Bidentatae Radix（ABR） from different origins as samples， to quantitatively analyze the chemical composition and chromaticity of ABR with different processing degrees， and clarify the correlation and change law between color and composition in the processing process of ABR， so as to provide reference for the quality evaluation of processed products of ABR. MethodThe colorimeter is used to measure the chromaticity values of three kinds of processing degrees of ABR in different origins to show the color value change trend during the processing process， and the color parameters of wine-processed and salt-processed products of ABR with different processing degrees were analyzed by principal component analysis（PCA）， orthogonal partial least squares-discriminant analysis（OPLS-DA） and other analysis methods. The contents of eight representative components of ABR were measured by high performance liquid chromatography（HPLC）， the correlation between chromaticity and each representative component was analyzed by Pearson correlation analysis， and the applicability of the selected eight representative components was further verified by Fisher linear discriminant analysis， and the wine-processed and salt-processed products of ABR with different processing degrees were grouped according to the degree of processing， and 48 samples of wine-processed and salt-processed products with different processing degrees were used as training samples. Taking the contents of 5-hydroxymethylfurfural， polypodine B， β-ecdysterone， 25R-inokosterone， 25S-inokosterone， ginsenoside Ro， chikusetsusaponin Ⅳa and polysaccharides as variables， the discriminant function was established respectively， and 12 samples of wine-processed and salt-processed products of ABR with different processing degrees were back-tested to verify the discriminant function and test the reliability of the function. ResultPCA and OPLS-DA results showed that ABR samples with different processing degrees were classified into clusters， and the results could significantly distinguish different processed products. During the process of wine and salt processing， the contents of 5-hydroxymethylfurfural， ginsenoside Ro， and chikusetsusaponin Ⅳa gradually increased with the deepening of the processing degree， while the contents of polypodine B， β-ecdysterone， 25R-inokosterone， 25S-inokosterone and polysaccharides showed a gradual decreasing trend， indicating these 8 components increased and decreased to different degrees in the process of wine and salt processing. The results of Pearson correlation analysis showed that the 5-hydroxymethylfurfural content of the samples with different processing degrees of wine-processed and salt-processed products were negatively correlated with the brightness value（L*） and the total color difference value（E*ab）（P<0.01）， and positively correlated with the red-green value（a*） and the yellow-blue value（b*）（P<0.01）， and that the content of polypodine B and polysaccharides were positively correlated with L* and E*ab（P<0.01）. The discriminant functions of wine-processed and salt-processed products of ABR were established by Fisher linear discriminant analysis， and their accuracy rates in the training samples were 93.75% and 95.83%， respectively. Twelve test samples of wine-processed and salt-processed products with different processing degree were back substitution， and the correct rate was 100%. ConclusionThe trend of composition and color changes of ABR with different processing degrees in different production areas is relatively consistent， and the color value can better distinguish ABR with different processing degrees， and the color of ABR is related to some representative components in the processing process， indicating that the color can provide reference for the identification of the processing degree of ABR and the prediction of component content.

Exploring Scientific Connotation of "Fried Charcoal Survivability" of Lonicerae Japonicae Flos Based on Color-composition Correlation / 中国实验方剂学杂志

ObjectiveTo explore the scientific connotation of fried charcoal survivability of Lonicerae Japonicae Flos（LJF） by analyzing the correlation between the color change and the intrinsic components during the processing of LJF Carbonisata（LJFC）， and taking pH， charcoal adsorption and microscopic characteristics as indexes. MethodLJFC samples with different degrees of processing were prepared according to the stir-frying time of 0.0， 1.5， 3.0， 4.5， 6.0， 7.5， 9.0， 10.5 min（numbered S1-S8）， and the contents of gallic acid， chlorogenic acid， cryptochlorogenic acid， rutin， luteoloside， isochlorogenic acid A and isochlorogenic acid C were determined by high performance liquid chromatography（HPLC）， and the L*（brightness）， a*（red-greenness） and b*（yellow-blueness） of LJFC samples with different degrees of processing were determined by spectrophotometer， and the correlation analysis and principal component analysis（PCA） between the contents of seven representative components and the color of the samples were carried out by SPSS 26. 0 and SIMCA-P 14.1. Then pH， adsorption force and characteristic structure of different samples of LJFC were detected and the processing pattern of LJFC was analyzed. ResultThe results of quantitative analysis revealed that the contents of luteoloside， rutin， chlorogenic acid and isochlorogenic acid A gradually decreased， and the contents of cryptochlorogenic acid， isochlorogenic acid C and gallic acid firstly increased and then decreased. The L* and b* of the sample powders decreased， and a* showed a trend of increasing and then decreasing. The L* and b* were positively correlated with the contents of chlorogenic acid， rutin， luteoloside， isochlorogenic acid A， b* was positively correlated with the content of gallic acid， and a* was positively correlated with the contents of cryptochlorogenic acid and isochlorogenic acid C. PCA revealed that samples could be clearly divided into 3 groups， S1-S2 as one group， S3-S5 as one group， and S6-S8 as one group， with S3 having the highest score. The results of regression analysis showed that only isochlorogenic acid C could be used to predict the contents of components by colorimetric values combined with regression equations. Physicochemical analysis showed that pH of LJFC increased with the increase of degree of charcoal stir-frying， while adsorption force showed a tendency of increasing and then decreasing， with the highest adsorption force in the S5 sample， and the non-glandular hairs， calcium oxalate clusters and pollen grains had a varying degree of decreasing with the deepening of processing degree， and the microstructures of S6-S8 samples were obviously charred with pollen grains almost invisible. ConclusionThe changes in chemical composition and color characteristics of LJFC during the processing have certain correlations， combined with the changes in physicochemical properties， S5 sample is found to be the optimal processed products， which can provide a reference for the processing standardization and quality evaluation of LJFC， and enrich the scientific connotation of fried charcoal survivability of LJF.

Aborto e raça no Brasil, Pesquisa Nacional de Aborto 2016 a 2021 / Abortion and race in Brazil, National Abortion Surveys 2016 to 2021

Resumo Examinamos a realização do aborto segundo cor ou raça das mulheres no Brasil usando dados de três edições da PNA, 2016, 2019 e 2021. Comparamos diferenciais raciais aplicando testes de diferenças de médias a dados de levantamentos separados, levantamentos combinados sem reponderação, e levantamentos combinados e reponderados. Na comparação usamos ainda modelos logísticos para a chance de realização de aborto. Os resultados indicam que há diferencial racial consistente nas três edições da PNA, com os percentuais de aborto entre as mulheres negras sendo mais elevados do que entre as mulheres brancas. Nos levantamentos combinados e reponderados, entre as mulheres negras de todas as idades a probabilidade de ter feito um aborto é de 11,03% enquanto entre as mulheres brancas é de 7,55%. Isso significa uma diferença de 3,5 pontos percentuais, que se traduz em uma probabilidade 46% maior para as negras, valores estatisticamente significantes para um intervalo de 5%. Regressões logísticas produzem resultados similares, com probabilidade média predita das mulheres negras de 12,61% e das mulheres brancas de 8,90%, também significantes. As diferenças raciais persistem estatisticamente significantes para várias combinações de edições da PNA. Porém, nos levantamentos isolados os testes de diferenças de média são estatisticamente significantes apenas em 2016.

Abstract We examine racial differentials in abortion among women in Brazil using data from three editions of the Brazilian National Abortion Survey (PNA), 2016, 2019 and 2021. We test the difference in means in data from separate surveys, combined surveys without reweighting, and combined and reweighted surveys. We also use logistic models for the chance of having an abortion. The results indicate that there is a consistent racial differential in the three editions of PNA, with the percentage of abortions among Black women being higher than among white women. In the combined and reweighted surveys, among Black women of all ages the probability of having had an abortion is 11.03% while among white women it is 7.55%. This means a difference of 3.5 percentage points, which translates into a 46% higher probability for Black women, statistically significant values for a 5% interval. Logistic regressions produce similar results, with an average predicted probability of 12.61% for Black women and 8.90% for white women, also significant. Racial differences remain statistically significant for various combinations of PNA editions. However, in the separate surveys, the difference in means tests are only statistically significant in 2016. Black refers to the group formed by Black and Brown women (pretas and pardas). Due to the small sample size, it is not possible to say much about the differences with Asian and Indigenous women.

Antimicrobial effect of phytosphingosine in acrylic resin

Abstract This study evaluated color stability (CS), anti-adherence effect (AAE), and cell viability of microorganisms on acrylic resin (AR) surface, treated associated or not with sodium percarbonate (SP). AR specimens were prepared, and color analysis was performed before and after the treatments and the CS was calculated. For analysis of AAE, the samples were sterilized by radiation in a microwave oven. Then samples were randomly distributed: phosphate-buffered saline (PBS - control), 0.5% sodium hypochlorite (SH), phytosphingosine (PHS), and phytosphingosine + SP (PHS+Na2CO3). The specimens remained in contact with solutions for 30 minutes and were later contaminated by Candida albicans. Aliquots were seeded in Petri dishes with Sabouraud Dextrose agar and incubated at 37°C for 24 hours. After the incubation, the number of colonies was counted. The cell viability of adhered microorganisms on the AR was evaluated and 20 fields were observed under an epifluorescence microscope, and the percentage of adhered viable cells was calculated. Data were compared (One-way ANOVA, Tukey, p<.05). As for CS, PHS+ Na2CO3 (0.4±0.1) resulted in less change than PBS (0.9±0.2), similar to the other groups (SH [1.0±0.3)]; PHS [0.9±0.2)]). There was no difference for all tested solutions regarding the ability to avoid microorganism adherence (p>0.05), but PHS (11.2±4.1) resulted in a smaller area of adhered viable cells, statistically different from SH (18.2±7.6) and PBS (26.4±10.8). It was concluded that PHS resulted in lower adhered viable cells and when associated with Na2CO3, also shows a lower effect on the CS of AR.

Resumo Este estudo avaliou estabilidade de cor (EC), efeito antiaderente (EAA) e viabilidade celular de microrganismos em superfície de resina acrílica (RA), tratada com solução de fitoesfingosina, associada ou não ao percarbonato de sódio (PS). Espécimes RA foram preparados e análise de cor foi realizada antes e após os tratamentos e EC foi calculada. Para análise de EAA, as amostras foram esterilizadas por radiação em forno de micro-ondas. Então foram distribuídas aleatoriamente: solução salina tamponada com fosfato (PBS - controle), hipoclorito de sódio 0,5% (SH), fitoesfingosina (PHS) e fitoesfingosina + SP (PHS+Na2CO3). Os espécimes permaneceram em contato com as soluções por 30 minutos e posteriormente foram contaminados por Candida albicans. Alíquotas foram semeadas em placas de Petri com ágar Sabouraud Dextrose e incubadas a 37°C por 24 horas. Após a incubação, o número de colônias foi contado. A viabilidade celular dos microorganismos aderidos na RA foi avaliada e 20 campos foram observados em microscópio de epifluorescência, e a porcentagem de células viáveis aderidas foi calculada. Os dados foram comparados (One-way ANOVA, Tukey, p<0,05). Quanto a EC, o PHS+ Na2CO3 [0,4 (0,1)] resultou em menor alteração que o PBS [0,9 (0,2)], semelhante aos demais grupos (SH [1,0 (0,3)]; PHS [0,9 (0,2)]). Não houve diferença para todas as soluções testadas quanto à capacidade de evitar a aderência de microorganismos (p>0,05), mas o PHS [11,2 (4,1)] resultou em uma área menor de células viáveis aderidas, estatisticamente diferente do SH [18,2 (7,6)] e PBS [26,4 (10,8)]. Concluiu-se que o PHS resultou em menor número de células viáveis aderidas e, quando associado ao Na2CO3, também apresenta menor efeito sobre o EC da RA.

The effect of whitening toothpastes on colour change and surface roughness of restorative materials

To examine the colour change and surface roughness of giomer, microhybrid composite and nanohybrid composite after brushing with whitening toothpastes. Disc-shaped samples of giomer, microhybrid composite and nanohybrid composite were divided into three subgroups(n=10), with the initial colour measured with a spectrophotometer and the surface roughness measured with a mechanical profilometer. The samples, which were immersed in coffee solution were brushed once a day with whitening toothpastes (Opalescence Cool Mint (OCM), Colgate Optic White Extra Power (COW) and Signal White Now Gold (SWN)) for 12 days. Colour change and surface roughness were measured again after the colouring-brushing cycle. All of the analyses were performed using appropriate statistical hypothesis tests. The highest increase in surface roughness was seen in the microhybrid composite group applied with SWN (p<0.05). The group with the least increase was the giomer group applied with SWN (p<0.05). While the least colour change was observed in the COW applied nanohybrid composite group (ΔE00=1,814), the most colour change occurred in the COW applied giomer group (ΔE00=5.943). After the use of whitening toothpastes, the roughness of giomer, microhybrid composite and nanohybrid composite surfaces was increased and a colour change above the clinically accepted value was observed.

El objetivo del presente estudio fue evaluar el cambio de color y la rugosidad de la superficie de giomer, resina compuesta microhíbrida y resina compuesta nanohíbrida posterior al cepillado con dentífricos blanqueadores. Las muestras en forma de disco de cada material se dividieron en tres subgrupos (n=10), con el color inicial medido con un espectrofotómetro y la rugosidad de la superficie medida con un perfilómetro mecánico. Las muestras, que se sumergieron en una solución de café, se cepillaron una vez al día con pastas dentales blanqueadoras (Opalescence Cool Mint (OCM), Colgate Optic White Extra Power (COW) y Signal White Now Gold (SWN)) durante 12 días. El cambio de color y la rugosidad de la superficie se midieron nuevamente después del ciclo de coloración-cepillado. El mayor aumento en la rugosidad de la superficie se observó en el grupo de la resina compuesta microhíbrida al que se le aplicó SWN (p<0,05). El grupo de menor incremento fue el grupo de giomer aplicado con SWN (p<0.05). Mientras que el menor cambio de color se observó en el grupo de resina compuesta nanohíbrida aplicado con COW (ΔE00=1,814), el mayor cambio de color ocurrió en el grupo de giomer con COW (ΔE00=5,943). Posterior al uso de pastas dentales blanqueadoras, la rugosidad del giomer, y de las resinas compuestas microhíbridas y nanohíbridas aumentó, siendo que se observó un cambio de color por encima del valor clínicamente aceptado.

Diagnóstico prenatal de vasa previa tipo 3, comunicación de un caso

La vasa previa es una patología poco frecuente en la que los vasos umbilicales se encuentran transcurriendo en las cercanías del orificio cervical interno. Habitualmente está asociada a inserción velamentosa del cordón, placenta succenturiata, inserción baja placentaria y fertilización in vitro. Tiene importantes implicancias perinatales el lograr un diagnóstico precoz en el segundo trimestre, porque se logra disminuir la mortalidad neonatal. Presentamos el primer caso de diagnóstico prenatal de vasa previa tipo 3 (una variante poco conocida) comunicado en el Perú en una gestante con placenta previa y sin diagnóstico hasta el tercer trimestre.

Vasa previa is a rare condition in which the umbilical vessels are found to run in the vicinity of the internal cervical os. It is usually associated with velamentous insertion of the umbilical cord, placenta succenturiata, low placenta insertion and in vitro fertilization. Early diagnosis in the second trimester has important perinatal implications because it reduces neonatal mortality. We present the first case of prenatal diagnosis of vasa previa type 3 (a little known variant) reported in Peru in a pregnant woman with placenta previa and undiagnosed until the third trimester.

Calidad de frutos de pitahaya (Selenicereus mega/anthus Haw.) sometidos a diferentes recubrimientos durante el almacenamiento

R E S U M E N La pitahaya amarilla es susceptible a los daños mecánicos durante la vida en anaquel, lo que genera pérdidas económicas considerables, las cuales se pueden mitigar a través de la aplicación de ceras. Por lo anterior se evaluó el efecto de recubrimientos comestibles en la calidad poscosecha de frutos de pitahaya amarilla con el fin de mantener la calidad por más tiempo. Se empleó un diseño de tres tratamientos completamente aleatorizados (cerabrix, cera natural y testigo sin aplicación). Las aplicaciones de ceras en los frutos de pitahaya disminuyeron la pérdida de masa (PM) en promedio en un 21% durante el almacenamiento, especialmente el recubrimiento con cerabrix. La firmeza de los frutos disminuyó drásticamente a partir de los seis días después de cosecha (ddc), al pasar de 5I,2 a 7,3 N. Durante la poscosecha, los frutos de pitahaya mostraron un aumento en la intensidad respiratoria (IR) al pasar de 10,48 a 26,35 mg.kg-I.hI de CO2, además, el pH aumentó de 4,I3 a 5,I7, mientras que los los sólidos solubles totales (SST), la acidez total titulable (ATT) y la relación de madurez (RM) disminuyeron, no obstante, la aplicación de cerabrix mantuvo los valores más bajos de sólidos solubles totales (SST). Los frutos con aplicación de recubrimiento comestible presentaron al final del almacenamiento menores valores de luminosidad (L* = 62,6) con una tonalidad más oscura que los frutos sin aplicación (L*= 66,4), los cuales mantuvieron el color amarillo característico de la pitahaya. La aplicación de recubrimientos comestibles no afectó las características organolépticas de los frutos de pitahaya.

Yellow pitahaya is very susceptible to mechanical damage during shelf life, which generates considerable economic losses, which can be mitigated through the application of coats. Therefore, the effect of edible coatings on the postharvest quality of yellow pitahaya fruits was evaluated in order to maintain quality for longer. A completely randomized three-treatment design was used (cerabrix, natural wax and control without application) was used. Wax applications in pitahaya fruits decreased PM by an average of 2I% during storage, especially the cerabrix coating. The firmness of the fruits decreased drastically from six days after harvest, when going from 5I.2 to 7.3 N. During the postharvest, the pitahaya fruits showed an increase in IR when going from I0.48 to 26.35 mg.kg-I.hI of CO2, in addition, the pH increased from 4.I3 to 5.I7, while the TSS, TTA and MI decreased, however, the application of cerabrix maintained the lowest values of TSS. Fruits with edible coating application showed lower luminosity values at the end of storage (L* = 62.6) with a darker hue than fruits without application (L*= 66.4), which maintained the characteristic yellow color of the pitahaya. The application of edible coatings did not affect the organoleptic characteristics of pitahaya fruits.

A pitaia amarela é muito suscetível a danos mecânicos durante a vida de prateleira, o que gera perdas econômicas consideráveis, que podem ser mitigadas com a aplicação de demãos. Portanto, avaliou-se o efeito de revestimentos comestíveis na qualidade pós-colheita de frutos de pitaia amarela, a fim de manter a qualidade por mais tempo. Um desenho de três tratamentos completamente randomizado foi usado. (cerabrix, cera natural e controle sem aplicação). A aplicação de cera em frutos de pitaia reduziu o PM em média 21% durante o armazenamento, principalmente o revestimento de cerabrix. A firmeza dos frutos diminuiu drasticamente após seis dias após a colheita, ao passar de 5I,2 para 7,3 N. Durante a pós-colheita, os frutos de pitaia apresentaram aumento da IR ao passar de I0,48 para 26,35 mg.kg-I.hI de CO2, além disso, o pH aumentou de 4,I3 para 5,I7, enquanto o TSS, TTA e MI diminuíram, porém, a aplicação de cerabrix manteve os menores valores de TSS. Frutos com aplicação de revestimento comestível apresentaram menores valores de luminosidade ao final do armazenamento (L* = 62,6) com tonalidade mais escura do que frutos sem aplicação (L*= 66,4), que mantiveram a coloração amarela característica da pitaia. A aplicação de coberturas comestíveis não afetou as características organolépticas dos frutos de pitaiaia.

Effect of applications of 1-MCP and ethylene on the ripening and degreening process of banana fruits cv. Barranquillo

The banana cv. Barranquillo (Musa acuminata, AAA, 'Gros Michel') is a highly desired fruit because of its productive potential and organoleptic quality but various aspects of the ripening process are unknown. The objective of this research was to evaluate the effect of applications of 1-MCP and ethylene on the ripening and degreening process. Two experiments were carried out at room temperature with fruits harvested at commercial maturity. The first four treatments evaluated maturation: control, ethylene, 1-MCP, and 1-MCP + ethylene. In the second experiment, different concentrations of ethylene based on ethephon (0, 100, 500 and 1000 µL L-1) were evaluated. The fruits treated with 1-MCP decreased the ripening process, and 1-MCP was a good alternative for conserving the fruits; the ethylene had opposite results. The color index of the skin, weight loss, firmness, total soluble solids, and maturity ratio had changes associated with the presence of ethylene. In the second experiment, the ethylene applications between 100 and 500 µL L-1 sufficiently stimulated degreening but accelerated the ripening process.

El banano cv. Barranquillo (Musa acuminata, AAA, 'Gros Michel') es un fruto muy apetecido por su potencial productivo y calidad organoléptica, pero se desconocen varios aspectos del proceso de maduración. El objetivo de esta investigación fue evaluar el efecto de la aplicación de 1-MCP y etileno en la maduración y en el proceso de desverdizado. Se realizaron dos experimentos a temperatura ambiente y con frutos cosechados en madurez comercial; en el primero, se evaluaron cuatro tratamientos, para entender la regulación de la maduración, estos fueron: testigo, etileno, 1-MCP y 1-MCP+etileno. En el segundo experimento, se evaluaron diferentes concentraciones de etileno, a base de etefon (0, 100, 500 y 1000 µL L-1). Los frutos tratados con 1- MCP presentaron una disminución en el proceso de maduración, por tanto, el 1-MCP, se convierte en una buena alternativa de conservación, mientras que con etileno, el proceso fue opuesto. Se evidenció que el índice de color de la epidermis, la pérdida de peso, la firmeza, los sólidos solubles totales y la relación de madurez se consideran cambios asociados a la presencia de etileno. En el segundo experimento se encontró que, aplicaciones de etileno entre 100 y 500µL L-1, se consideran suficientes para estimular el desverdizado, pero aceleran el proceso de maduración.

Impact of color vision deficiency on the quality of life in a sample of Indian population: Application of the CVD-QoL tool

Purpose: To investigate the quality of life (QoL) in a sample of color vision deficit (CVD) patients in India and how color vision deficiency affects them psychologically, economically, and in productivity related to their work and occupation. Methods: A descriptive and case–control study design using a questionnaire was conducted on N = 120 participants, of whom 60 were patients of CVD (52 male and eight female) who visited two eye facilities in Hyderabad between 2020 and 2021 and 60 were age?matched normal color vision participants who served as controls. We validated English–Telugu adapted version of CVD?QoL, developed by Barry et al. in 2017 (CB?QoL). The CVD?QoL consists of 27 Likert?scale items with factors (lifestyle, emotions, and work). Color vision was assessed using the Ishihara and Cambridge Mollen color vision tests. A six?point Likert scale was used, with lower scores indicating poor QoL (from 1 = severe issue to 6 = no problem). Results: The CVD?QoL questionnaire’s reliability and internal consistency were measured, including Cronbach’s ? (? =0.70–0.90). There was no significance between the group in age (t = ?1.2, P = 0.67) whereas the Ishihara colour vision test, scores showed a significant difference (t = 4.50, P < 0.001). The QoL scores showed a significant difference towards lifestyle, emotions and work (P = 0.001). The CVD group had a poorer QoL score than the normal color vision group odds ratio [OR] =0.31, 95% confidence interval [CI], (P = 0.002, CI = 0.14–0.65, Z = 3.0) . In this analysis, a low CI indicated that the OR was more precise. Conclusion: Color vision deficiency affects Indians’ QoL, according to this study. The mean scores of lifestyle, emotions, and work were lower than the UK sample. Since CVD is underreported and possibly affects developing countries more, advocacy for a new health care plan on CVD is essential. Increasing public understanding and awareness could also help diagnosing the CVD population

Ozonation of Brazil nuts (Bertholletia excelsa H.B.K. ): effect of column height on the saturation process and changes in quality / Ozonização de castanha-do-Brasil (Bertholletia excelsa H.B.K. ): efeito da altura da coluna no processo de saturação e alterações na qualidade

The objective of this study is to examine the saturation process in a column containing Brazil nuts and possible changes in the quality of the product. Brazil nut samples were initially placed in a cylindrical PVC column 15 cm in diameter and 110 cm in height. The ozone gas concentrations of 2.5, 4.5, 9.0, and 14.0 mg L-1 and a flow rate of 3.0 L min-1 were applied at a temperature of 25 ºC. Ozone gas was injected at the base of the cylindrical column, and the seed column height values adopted were 0.25, 0.50, and 0.75 m. Saturation concentration and time were determined. To measure possible changes in the quality of ozonized Brazil nuts, moisture and color, as well as qualitative variables of the crude oil were evaluated at the exposure times of 0, 3, 6, 9, and 12 h. To evaluate the quality of the crude oil extracted from ozonized nuts, the free fatty acid content, peroxide value, and iodine value were analyzed. Increasing ozonation times increased ozone concentration at all inlet gas concentrations. Saturation time decreased as the inlet gas concentration was increased, at the different product column heights. There was no change in product moisture in response to ozonation. Ozonation did not induce significant changes in color or in the crude oil, due to the triple interaction between column height, ozone concentration, and exposure time. In conclusion, the height of the product's column influences saturation time and concentration during the ozonation process. Considering the color of the product and characteristics of its crude oil, the use of ozone under the conditions adopted in the present study does not affect the quality of Brazil nuts to the point of rendering them unmarketable.

O objetivo do presente trabalho é estudar o processo de saturação em coluna contendo castanha-do-Brasil e possíveis alterações na qualidade do produto. Inicialmente as amostras de castanha-do-Brasil foram acondicionadas em coluna cilíndrica de PVC de 15 cm de diâmetro e 110 cm de altura. Foram adotadas as concentrações do gás ozônio de 2,5, 4,5, 9,0 e 14,0 mg L-1 e vazão de 3,0 L min-1, na temperatura de 25 ºC. O gás ozônio foi injetado na base da coluna cilíndrica e os valores adotados de altura da coluna de grãos foram de 0,25, 0,50, e 0,75 m. Determinaram-se o tempo e a concentração de saturação. Na avaliação de possíveis alterações na qualidade de castanhas-do-Brasil ozonizadas foram determinados a umidade, coloração e variáveis qualitativas do óleo bruto, com tempos de exposição de 0, 3, 6, 9 e 12 h. Para avaliação da qualidade do óleo bruto extraído de castanhas ozonizadas foram analisadas o teor de ácidos graxos livres, o índice de peróxido e o índice de iodo. A elevação do período de ozonização promoveu aumento da concentração do ozônio para todas as concentrações de entrada do gás. No que se refere aos valores de tempo de saturação, à medida que se elevou a concentração de entrada do gás, houve redução do tempo de saturação, nas diferentes alturas de coluna do produto. Não houve variação da umidade do produto em decorrência da ozonização. A ozonização não provocou alterações significativas na cor e no óleo bruto, em decorrência da interação tripla entre altura da coluna do produto, concentração do ozônio e tempo de exposição. É possível concluir que a altura da coluna do produto influencia o tempo e a concentração de saturação, durante o processo de ozonização. O uso do ozônio nas condições adotadas no presente estudo não afeta a qualidade da castanhado-Brasil, considerando-se a cor do produto e características do óleo bruto, de tal forma a inviabilizar a comercialização.

Un caso de leucismo en el Juil de Jamapa, Rhamdia laticauda (Siluriformes, Heptapteridae) en el noreste del estado de Oaxaca, México

Se reporta la primera observación de un espécimen leucístico en el Juil de Jamapa, Rhamdia laticauda en el noreste del estado de Oaxaca. En un estudio ictiológico de la Reserva de la Biosfera Tehuacán-Cuicatlán en el río Xiquila de la cuenca alta del río Papaloapan, el pez se capturó con pesca eléctrica y se fotografió. El bagre vivo mostró una reducción de pigmentos en la piel, manchas blancas y ojos negros normales. Esto contribuye al conocimiento de la variabilidad intraespecífica y la historia natural de R. laticauda. Se discuten las causas potenciales de esta anomalía de color.

Here, we report the first observation of a leucistic specimen in the Rock catfish, Rhamdia laticauda in the Northeast of Oaxaca, Mexico. We caught the specimen by electric fishing and then photographed during an ichthyological survey carried out in the Tehuacán-Cuicatlán Biosphere Reserve in the Xiquila River of the upper Papaloapan River basin. The live catfish showed a lack of pigment in the skin, white spots, and normal eye color. This information contributes to the knowledge about intraspecific variability and natural history of R. laticauda. We discuss the potential causes of this color anomaly.

Value of the strain ratio in the differential diagnosis of intraocular tumors by elastosonography: A retrospective case-control study

Purpose: To examine the role of the strain ratio in elastosonography for the differential diagnosis of common intraocular tumors such as choroidal melanoma, choroidal hemangioma, choroidal metastatic carcinoma, and retinoblastoma. Methods: This study included patients suffering from intraocular space?occupying lesions and who visited Beijing Tongren Eye Center of Beijing Tongren Hospital affiliated to Capital Medical University from June 2016 to March 2020. All patients underwent a physical examination, fundus examination with mydriasis, color Doppler ultrasonography, elastosonography, magnetic resonance imaging (MRI), and fundus angiography within 1 week. All patients were grouped as choroidal melanoma, choroidal metastatic carcinoma, retinoblastoma, choroidal hemangioma, and optic disk melanocytoma. A receiver operating characteristic (ROC) curve analysis was performed to assess the strain ratio for diagnosing malignant intraocular tumors. Results: A total of 155 patients (161 eyes) were recruited. The strain ratios measured were 39.59 ± 15.92 for choroidal melanoma, 36.85 ± 13.64 for choroidal metastatic carcinoma, 38.93 ± 17.27 for retinoblastoma, 13.42 ± 10.93 for choroidal hemangioma, and 3.84 ± 1.32 for optic disk melanocytoma. The strain ratios of the three malignant lesions were significantly higher than those of the two benign lesions (all P < 0.001). The area under the ROC curve was 0.95 ± 0.028. The optimal cutoff point was 22.67, with 85.7% sensitivity and 96.4% specificity. Conclusion: There were significant differences in elasticity between the malignant and benign intraocular tumors. The strain ratio using elastosonography could serve as an important auxiliary examination to distinguish between benign and malignant intraocular tumors

The effect of Phytosphingosine and bioactive glass-ceramics in preventing dental enamel erosion

Abstract This study evaluated the effect of phytosphingosine (PHS) and bioactive glass-ceramic (Biosilicate) on dental enamel in terms of color alteration (ΔE), microhardness, and surface roughness when submitted to erosive challenge (EC). Sixty specimens of bovine teeth (6×6×2mm) were obtained. Initial color (Easyshade, VITA), KHN (HMV-2, Shimadzu), and Ra (SJ-201P, Mitutoyo) measurements were performed. Specimens were separated into groups according to treatments: PHS, 10% Biosilicate, PHS+10% Biosilicate, and artificial saliva (control) and submitted to EC with Coca-Cola for 2 min. This cycle was repeated 4 times daily/15 days. Between cycles, specimens remained in artificial saliva (2 h/37°C). After daily cycles, they were also stored in artificial saliva at 37ºC. Final color, microhardness, and surface roughness measurements were done. Color and KHN data were analyzed by one-way ANOVA, Tukey's test; and Ra, by 2-way ANOVA, repeated measures, and Tukey's test (p<.05). The highest ΔE occurred in Saliva+EC (p<.05). Groups treated with PHS presented lower color change than Saliva+EC (p<.05). All the groups presented mean values above the 50:50% perceptibility (50:50%PT) and acceptability (50:50%AT) thresholds, except for control that showed mean value above 50:50%PT but below 50:50%AT. Biosilicate+EC showed higher relative microhardness than Saliva+EC (p<.05), but was similar to PHS+EC and PHS+Biosilicate+EC. Final enamel surface roughness increased for all the groups (p<.05), except for the control. The Biosilicate may prevent enamel mineral loss induced by erosion better than saliva. The PHS associated or not to Biosilicate demonstrated better color stability than saliva.

Resumo Este estudo avaliou o efeito da Fitoesfingosina (PHS) e da vitrocerâmica bioativa (Biosilicato) sobre o esmalte dental em termos de alteração de cor (ΔE), microdureza (KHN) e rugosidade superficial, quando submetido a desafio erosivo (DE). Sessenta espécimes de dentes bovinos (6×6×2mm) foram obtidos. Foram realizadas leituras de cor inicial (Easyshade, VITA), microdureza (HMV-2, Shimadzu) e rugosidade superfícial (SJ-201P, Mitutoyo). Os espécimes foram separados em grupos de acordo com os tratamentos: PHS, Biosilicato a 10%, PHS+Biosilicato a 10%, e saliva artificial (controle). Em seguida, foram submetidos a DE com Coca-Cola por 2 min. Esse ciclo foi repetido 4 vezes/dia por 15 dias. Entre os ciclos, as amostras foram mantidas em saliva artificial (2 h/37°C). Após os ciclos diários, os espécimes também foram armazenados em saliva artificial a 37ºC. Foram realizadas leituras finais de cor, microdureza e rugosidade superficial. Os dados de cor e microdureza foram analisados ​​por ANOVA de uma via, teste de Tukey; e dados de rugosidade superficial, por ANOVA de duas vias, teste de Tukey (p<.05). A maior ΔE ocorreu em Saliva+DE (p<.05). Grupos tratados com PHS apresentaram menor alteração de cor do que Saliva+DE (p<.05). Biosilicate+DE demonstrou valores intermediários, similar (p>.05) aos outros grupos, exceto Saliva+DE. Todos os grupos presentaram média acima dos limites 50:50% de perceptibilidade (50:50%LP) e aceitabilidade (50:50%LA) exceto o controle que demonstrou média acima do 50:50%LA mas abaixo do 50:50%LP. Biosilicate+DE mostrou maior microdureza realativa do que Saliva+DE (p<.05), mas similar a PHS+DE e PHS+Biosilicato+DE. A rugosidade de superfície do esmalte aumentou para todos os grupos, exceto para o controle que presentou a menor alteração (p<.05). O Biosilicato apode prevenir perda mineral do esmalte indizido pela erosão melhor que a saliva. O PHS associado ou não ao Biosilicato demonstrou melhor estabilidade de cor que a saliva.

Estabilidad de Color de Tres Resinas Nanohíbridas en Relación al Tipo Pulido Realizado

El color de las restauraciones se considera una de las características más exigidas por los pacientes, cuyo éxito final dependerá de mantenerse en el tiempo, sin sufrir alteraciones. El objetivo de este estudio fue determinar la estabilidad de color que experimentan las resinas al ser sumergidas en una sustancia pigmentante en función al factor tiempo y al tipo de pulido final realizado. Estudio experimental in vitro de tres resinas de nanopartículas: Filtek Z-350 XT® (3M), Brillant NG® (Coltene), Tetric N-Ceram® (Vivadent) donde se comparó la estabilidad de color al ser sumergidas en café. Se confeccionaron 120 discos de resinas (color esmalte A3) divididos posteriormente en dos grupos: Grupo 1 protocolo habitual de pulido Grupo 2: protocolo habitual más sellador fotocurable Biscover® (Bisco). Las muestras fueron almacenadas en agua destilada en estufa a 37° durante 24 hs para su hidratación. Se registró el color utilizando el colorímetro Kónica Minolta®. Posteriormente se sumergieron las muestras en café, y se tomó nuevamente el color a las 24 hs y a los 7 días. Los datos fueron analizados estadísticamente mediante análisis de varianza y test de compación de Tukey. Se observó que la resina que más se pigmentó en el grupo 1 correspondió a la resina Filteck Z-350 con DE: 4,68 a las 24 hs y DE: 5,53 a los 7 días. Al analizar el grupo 2 las tres resinas se mantuvieron en valores bajos de DE: 0,96 a 1,42 en ambos períodos. Al sumergir las resinas en una sustancia pigmentante, la alteración del color se va produciendo en función del tiempo. Sin embargo, el uso complementario de un sellador fotocurable como pulido mejora significativamente la estabilidad de color en estos materiales, factores que el clínico debe tener en cuenta para lograr el éxito de sus restauraciones.

The color of the restorations is considered one of the characteristics most demanded by patients, whose final success will depend on being maintained over time, without undergoing alterations. The objective of this study was to determine the color variations experienced by reinforced resins when immersed in a pigmenting substance as a function of the time factor and the type of final polishing performed. In vitro experimental study of three nanoparticle resins: Filtek Z-350 XT® (3M), Brillant NG® (Coltene), Tetric N-Ceram® (Vivadent) where color stability was compared when immersed in coffee. 120 Discs of resins (enamel color A3) were made and subsequently divided into two groups: Group 1 usual polishing protocol Group 2: usual protocol plus Biscover® (Bisco) light-curing sealer. The samples were stored in distilled water in an oven at 37 ° for 24 hours for hydration. Color was recorded using the Konica Minolta® colorimeter. Subsequently, the samples were immersed in coffee, and the color was taken again at 24 hours and 7 days. Data were statistically analyzed using analysis of variance and Tukey's comparison test. It was observed that the most pigmented resin in group 1 corresponded to the Filteck Z-350 resin with DE: 4.68 at 24 hours and DE: 5.53 at 7 days. When analyzing group 2, the three resins maintained low DE values: 0.96 to 1.42 in both periods. By immersing the resins in a pigmenting substance, the change in color occurs over time. However, the complementary use of a light-curing sealer such as polishing significantly improves color stability in these materials, factors that the clinician must take into account to achieve the success of their restorations.

Whitening Effect of Different Toothpastes on Bovine Dental Enamel: an in situ study

Abstract The aim of this in situ study was to evaluate color change, surface roughness, gloss, and microhardness in tooth enamel submitted to whitening and remineralizing toothpastes. Fifteen healthy adults (REBEC - RBR-7p87yr) (with unstimulated salivary flow ≥ 1.5 ml for 5 minutes, pH=7) wore two intraoral devices containing four bovine dental fragments (6 x 6 x 2 mm). Participants were randomly assigned and instructed to toothbrush the devices with the tested toothpastes (30 days): CT: conventional; WT: whitening; WTP: whitening with peroxide, and RT: remineralizing toothpaste. A washout period of 7 days was established. Readouts of color, gloss, surface roughness, and microhardness were performed before and after brushing. The results demonstrated no color, gloss, and microhardness differences (p>0.5). The samples brushed with WTP (0.2(0.7) showed higher surface roughness (p=0.0493) than those with WT (-0.5(1.0). The toothpastes did not alter the properties of the dental enamel, except for the roughness. Toothpaste with an abrasive system based on sodium bicarbonate and silica, and that contains sodium carbonate peroxide increased the surface roughness of the enamel.

Resumo O objetivo deste estudo in situ foi avaliar a alteração de cor, rugosidade superficial, brilho e microdureza em esmalte dentário submetido a dentifrícios clareadores e remineralizantes. Quinze adultos saudáveis (REBEC - RBR-7p87yr) (com fluxo salivar não estimulado ≥ 1.5 mL por 5 minutos, pH = 7) usaram dois dispositivos intrabucais contendo quatro fragmentos dentários bovinos (6 x 6 x 2 mm). Os participantes foram aleatoriamente designados e instruídos a escovar os aparelhos com os dentifrícios testados (30 dias): CO: convencional; CL: clareador; CLP: clareador com peróxido e RE: remineralizante. Foi estabelecido um período de washout de 7 dias. Leituras de cor, brilho, rugosidade superficial e microdureza foram realizadas antes e após a escovação. Os resultados não demonstraram diferenças na cor, brilho e microdureza. As amostras escovadas com CLP apresentaram maior rugosidade superficial (p=0,0493) do que aquelas com CL. Os dentifrícios não alteraram as propriedades do esmalte dental, exceto a rugosidade. O dentifrício com sistema abrasivo à base de bicarbonato de sódio e sílica, e que contém peróxido de carbonato de sódio aumentou a rugosidade de superfície do esmalte.