The visual and instrumental analyses of different single-shade resin composites / Análisis visual e instrumental de diferentes resinas compuestas omnicromáticas

Abstract The purpose of this study was to evaluate the color adaptation of single-shade resin composites applied to different tooth shades. A total of 108 class III preparations (n=6) were performed on the acrylic denture maxillary incisors (2mm depth and 2mm height). 5 single-shade resin composites (Vittra APS Unique, Omnichroma, ZenChroma, Clearfil Majesty ES-2 Universal, Charisma Topaz One) and 1 multishade resin composite (Estelite Asteria) were placed in the cavities and polished. I performed visual and instrumental color analyses. The CIEDE2000 formula was used to assess the shade differences (ΔE) between teeth and restorations. The obtained ΔE values were recorded and statistically analyzed. For the instrumental analysis, ZenChroma in A1 shade groups showed statistically significant higher differences (p<0.05). Among all tested materials, A3 shade groups showed lower ΔE values (p<0.05). For the visual analysis, there were no significant differences between materials and scores in A1 and A3 shade groups (p>0.05). There were statistically significant differences between the materials and the scores in A2 shade groups (p<0.05). As a result of this study, it was concluded that, making esthetic restorations with single-shade resin composites promises proper color adaptation, but their properties still need improvement. Single-shade resin composites can reduce chair-time and technical sensitivity with good color matching.

Resumen El objetivo de este estudio fue evaluar la adaptación del color de resinas compuestas omnicromáticas. Se realizaron un total de 108 preparaciones de clase III (n=6) en los incisivos superiores de prótesis acrílicas (2mm de profundidad y 2mm de altura). Se colocaron cinco resinas compuestas omnicromáticas (Vittra APS Unique, Omnichroma, ZenChroma, Clearfil Majesty ES-2 Universal, Charisma Topaz One), además de una resina multitono (Estelite Asteria) en las cavidades y se pulieron. Se realizó el análisis de color visual e instrumental. Se utilizó la fórmula CIEDE2000 para evaluar las diferencias de tono (ΔE) entre dientes y restauraciones. Los valores de ΔE obtenidos se registraron y analizaron estadísticamente. Para el análisis instrumental, ZenChroma en los grupos de color A1 mostró diferencias mayores estadísticamente significativas (p<0,05). Entre todos los materiales probados, los grupos de tonos A3 mostraron valores de ΔE más bajos (p<0.05). Para el análisis visual, no hubo diferencias significativas entre materiales y puntuaciones en los grupos de color A1 y A3 (p>0,05). Hubo diferencias estadísticamente significativas entre los materiales y las puntuaciones en los grupos de color A2 (p<0,05). Como resultado de este estudio, se concluyó que la realización de restauraciones estéticas con resinas compuestas omnicromáticas promueve una adecuada adaptación del color, pero aún necesitan mejorar sus propiedades. Las resinas compuetas omnicromáticas pueden reducir el tiempo de atención clínica y la sensibilidad técnica con una adecuada combinación de colores.

Exploring alternatives for securing anatomical structures in capturing digital images: A comparative analysis.

Teaching veterinary anatomy using digital platforms requires improved image quality, which may influence the fixation process. This study aimed to compare four embalming solutions for high-colour-quality images of different tissues compared to the original image. Four equine left pelvic limbs were cut into metameres and divided equally for application of 10% formaldehyde, 96% glycerine, 33% hypersaturated NaCl solution and modified Larssen solution, respectively, which was maintained for 3 days. After drying for 3 days at room temperature, photographs were obtained at time 0 (T0), without any fixation process (original colour); time 1 (T1), immediately after removal from the solutions; and every 24 h for 3 days (T2-T4). The image colour quality was investigated by digitally evaluating the cortical bone, tendon and bone marrow using histograms and CIEDE2000 as well as by 10 specialists in an online survey. CIEDE2000 and histograms revealed that all fixation solutions changed the original tissue colour at all the time points (p < 0.0001). According to the specialists, the 33% saline solution produced the best results compared to the original one. The modified Larssen solution demonstrated better results for the tendon, marrow and cortical bone at T3 (p = 0.0015). Considering the colour of digital images, the modified Larssen solution provided the best results; however, the visual evaluation by the specialists revealed the 33% saline solution as the best.

The Effects of Mouthwashes on the Color Stability of Resin-Based Restorative Materials / Efecto de los enjuagues orales en la estabilidad del color de materiales restauradores a base de resina

Abstract: Objective: This study investigated the effects of three types of mouthwash on the color stability of three resin-based restorative materials (nanohybrid resin composite, sonic-activated bulk-fill material, and compomer). Materials and Methods: To this end, 120 cylindrical disc specimens were prepared and polished, after which they were incubated in distilled water for 24 hours for post-polymerization. The baseline color values of each specimen were measured with a spectrophotometer, then the specimens were randomly divided into four groups. Following immersion in the mouthwashes for 24 hours, the specimens were rinsed with distilled water and dried before the color measurement was repeated. The values of color change (ΔE₀₀) were subsequently calculated. A two-way analysis of variance and Duncan's post hoc multiple comparison tests were conducted to determine statistically significant differences among the restorative materials. Results: All samples showed discoloration after immersion, albeit some instances of discoloration were imperceptible. In this respect, a statistically significant difference was found among the restorative materials and mouthwashes (p<0.05). Imperceptible ΔE₀₀ values were derived on the nanohybrid resin composite and compomer, but perceptible and acceptable ΔE₀₀ values were detected on the sonic-activated bulk-fill materials (p<0.05). The clinically unacceptable discoloration was observed on the sonic-activated bulk-fill composite immersed in Listerine®. Conclusions: Clinicians should make recommendations based on the potential staining capacity of mouthwashes prescribed for daily use in restorative materials. In this way, the need for renewal of restorations due to discoloration could be avoided.

Resumen: Objetivo: Este estudio investigó los efectos de tres tipos de enjuague bucal en la estabilidad del color de tres materiales de restauración a base de resina (resina nanohíbrida, resina bulk-fill de activación sónica y compómero). Materiales y Métodos: Para ello se prepararon y pulieron 120 muestras de discos cilíndricos, después de lo cual se incubaron en agua destilada durante 24 horas pospolimerización. Los valores de color de base de cada muestra se midieron con un espectrofotómetro, después las muestras se dividieron aleatoriamente en cuatro grupos. Tras la inmersión en los enjuagues bucales durante 24 horas, los especímenes se enjuagaron con agua destilada y se secaron antes de repetir la medición del color. Posteriormente se calcularon los valores de cambio de color (ΔE₀₀). Se llevó a cabo un análisis bidireccional de la varianza y las pruebas de comparación múltiple post hoc de Duncan para determinar las diferencias estadísticamente significativas entre los materiales de restauración. Resultados: Todas las muestras mostraron decoloración después de la inmersión, aunque algunos casos esta fue imperceptible. Se encontró una diferencia estadísticamente significativa entre los materiales de restauración y los enjuagues bucales (p<0,05). Se obtuvieron valores imperceptibles de ΔE₀₀ en el compuesto de resina nanohíbrida y el compómero, pero se detectaron valores perceptibles y aceptables de ΔE₀₀ en la resina bulk-fill activada sónicamente (p<0,05). Se observó una decoloración clínicamente inaceptable en la resina bulk-fill activada sónicamente inmersa en Listerine®. Conclusiones: Los clínicos deben hacer recomendaciones basadas en la capacidad potencial de coloración de los enjuagues bucales prescritos para uso diario en los materiales de restauración. De esta manera, se podría evitar la necesidad de renovar las restauraciones debido a la decoloración.

Color, lightness, chroma, hue, and translucency adjustment potential of resin composites using CIEDE2000 color difference formula.

OBJECTIVE: To evaluate color, lightness, chroma, hue, and translucency adjustment potential of resin composites using CIEDE2000 color difference formula. METHODS: Three resin composites (Filtek Universal, Harmonize, and Omnichroma) were tested. Two types of specimens were prepared: an outer base shade with an inner hole filled with test shades and single-composite specimens of all shades. Spectrorradiometric reflectances measurements and subsequent CIELAB color coordinates and translucency parameter (TP) were performed. Color (CAP00 ), lightness, chroma, hue, and translucency (TAP00 ) adjustment potential using CIEDE2000 color difference were computed. Color and transparency differences among composite materials and shades were statistically tested (P < 0.05). RESULTS: Positive CAP00 and TAP00 values were found for majority of tested materials. CAP00 values ranged from -0.14 to 0.89, with the highest values found for Omnichroma (>0.75 in all cases). TAP00 values ranged from -0.06 to 0.86 with significant translucency differences among dual and single specimens. Omnichroma exhibited the highest adjustment potential for all color dimensions studied. CONCLUSIONS: Lightness, hue, chroma, and translucency adjustment potential have been introduced using CIEDE2000 color difference formula, and have shown their usefulness to evaluate blending effect in dentistry. Color coordinates and translucency adjustment potential were dependent on dental material. Omnichroma exhibited the most pronounced blending effect. CLINICAL SIGNIFICANCE: Resin composites with increased color and translucency adjustment may simplify shade selection, making this process easier and less time consuming. Furthermore, these materials might facilitate challenging and complex color matching situations.

A Comparison of the Bleaching Effectiveness of Chlorine Dioxide and Hydrogen Peroxide on Dental Composite

This study was carried out to verify if composites could be bleached using chlorine dioxide as compared with hydrogen peroxide. 3M ESPE Filtek Z350 Universal Restorative discs were prepared (n=40), with dimensions 5 mm diameter x 2 mm thickness. The discs were divided into 4 groups of 10 discs each. Color assessment was performed by CIEDE2000. The discs were stained with coffee, tea, wine and distilled water (control) solutions for 14 days, 5 hours daily. Color assessment was repeated on stained discs and followed by bleaching of 5 discs from each group using chlorine dioxide and hydrogen peroxide in-office systems. Finally, a last color assessment was performed and compared statistically. DE2000 after bleaching was very close to baseline for both the bleaching agents, although chlorine dioxide showed better results than hydrogen peroxide. After staining, there was a clinically significant discoloration (∆E2000≥3.43) for the tea, coffee and wine groups, and discoloration (∆E2000) was seen more in the wine group as compared to tea and coffee. Overall, the control group (distilled water) had the least color change in the three intervals. After bleaching, the color in all specimens returned close to the baseline. The color differences between bleaching and baseline were less than 3.43 for all groups. The obtained results show that chlorine dioxide is slightly superior to hydrogen peroxide in the bleaching of composites, while maintaining the shade of the composite close to the baseline.

Este estudo foi realizado para verificar se resinas compostas podem ser clareadas com uso do dióxido de cloro, em comparação com peróxido de hidrogênio. Foram preparados discos com resina restauradora Filtek Z350 3M ESPE (n=40), com dimensões 5 mm de diâmetro × 2 mm de espessura. Os discos foram divididos em 4 grupos de 10 discos cada. A avaliação da cor foi realizada por meio do CIEDE2000. Os discos foram manchados com soluções de café, chá, vinho e água destilada (controle) por 5 h diárias durante 14 dias. A avaliação da cor foi repetida nos discos manchados e seguida por clareamento de 5 discos de cada grupo, utilizando dióxido de cloro ou peróxido de hidrogênio pela técnica de consultório. Finalmente, uma última avaliação da cor foi realizada e as técnicas comparadas estatisticamente. DE2000 após o clareamento foi muito próxima ao baseline, para ambos os agentes clareadores, embora o dióxido de cloro tenha mostrado melhores resultados do que o peróxido de hidrogênio. Após o manchamento, houve uma descoloração clinicamente significativa (ΔE2000≥3,43) para os grupos de chá, café e vinho, sendo que o clareamento (ΔE2000) foi melhor obtido com o grupo do vinho, em comparação com chá e café. No geral, o grupo controle (água destilada) teve a menor mudança de cor nos três intervalos. Após o clareamento, a cor em todos os espécimes voltou próxima ao baseline. As diferenças de cor entre o clareamento e o baseline foram inferiores a 3,43 para todos os grupos. Os resultados indicam que o dióxido de cloro é ligeiramente superior ao peróxido de hidrogênio no clareamento de resinas compostas, mantendo a cor próxima à escala do baseline.