Comparison of instrumental methods for color change assessment of Giomer resins.

Objectives: The aim of this study was to compare the color change of the Giomer resin composite (Beautifil-Bulk) by using photographs obtained with a smartphone (iPhone 6S) associated with Adobe Photoshop software (digital method), with the spectrophotometric method (Vita Easyshade) after immersion in different pigment solutions. Materials and Methods: Twenty resin composite samples with a diameter of 15.0 mm and thickness of 1.0 mm were confectioned in A2 color (n = 5). Photographs and initial color readings were performed with a smartphone and spectrophotometer, respectively. Then, samples were randomly divided and subjected to cycles of immersion in distilled water (control), açai, Coke, and tomato sauce, 3 times a day, 20 minutes for 7 days. Later, new photographs and color readings were taken. Results: The analysis (2-way analysis of variance, Holm-Sidak, p < 0.05) demonstrated no statistical difference (p < 0.005) between the methods in all groups. Similar color changes were observed for all pigment solutions when using the spectrophotometric method. For the digital method, all color changes were clinically unacceptable, with distilled water and tomato sauce similar to each other and with statistical differences (p < 0.005) for Coke and açai. Conclusions: Only the tomato sauce produced a color change above the acceptability threshold using both methods of color assessment. The spectrophotometric and digital methods produce different patterns of color change. According to our results, the spectrophotometric method is more recommended in color change assessment.

Avaliação da alteração de cor de uma resina composta "beautiful bulk" submetida à imersão em soluções pigmentantes / Color change evaluation of a composite resin "beautiful bulk" submitted to immersion in pigmentant solutions

Objetivo:O objetivo do estudo foi verificar, in vitro, a alteração de cor da resina composta Beautiful-Bulk®, exposta aos líquidos pigmentantes. Métodos:Foram confeccionados 60 espécimes da resina (15,0 mm de diâmetro e 1,0 mm de espessura, n = 5) nas cores A2, B2 e C2. Os espécimes foram mantidos em uma sala escura por sete dias, em ambiente seco, a 37 °C e, em seguida, foram fotografados com aparelho celular iPhone 6S®. Os espécimes foram divididos aleatoriamente e submetidos a ciclos de imersão em quatro líquidos: água destilada (controle), suco de açaí, Coca-Cola® e molho de tomate. As imersões foram realizadas em sete e quatorze dias de forma cíclica, após a confecção dos espécimes, três vezes ao dia, durante 20 minutos. Ao fim de cada ciclo, novas fotografias foram realizadas. As imagens foram analisadas no programa Adobe Photoshop® e os dados convertidos em L*a*b através de um histograma. A variação de cor (∆E) foi analisada pela escala CIE-Lab. Resultados:A análise dos resultados (One-way ANOVA, Teste de Tukey, p < 0,05) demonstrou que o grupo controle produziu maior alteração de cor (p < 0,05) em sete e quatorze dias na cor A2. A cor B2, no ciclo de quatorze dias, apresentou maior alteração de cor (p < 0,05) para os espécimes imersos em molho de tomate sem diferença estatística (p > 0,05) do controle. Para a cor C2, os espécimes imersos em molho de tomate tiveram maior alteração de cor (p < 0,05) em sete dias. Conclusão:Conclui-se que todas as substâncias pigmentantes e a água destilada foram capazes de produzir grandes alterações de cor na resina Beautifil Bulk®. Existe uma interação significativa entre a cor da resina e agentes pigmentantes.

Aim: This study sought to verify, in vitro, the color change of the nanoparticle composite resin, Beautiful Bulk®, exposed directly to pigmented liquids. Methods: Sixty test specimens were made in a Metal matrix (15.0 mm X 1.0 mm) using composite resin (n = 5) in colors A2, B2, and C2. The specimens were photographed with a smartphone (iPhone 6S®) seven days after the preparation. The specimens were kept in the dark for seven days, dry, at 37°C. The specimens were then randomly divided and immersed in four liquids: distilled water (control), açaí juice, Coca-Cola®, and tomato sauce. The immersions were performed in seven and fourteen days cyclically, three times a day, for 20 minutes. At the end of each immersion cycle, new photographs were taken with the same smartphone. The images were analyzed in the Adobe Photoshop® program, and the data was converted to L* a* b* through a histogram. The color variation (∆E) was analyzed by the CIE-Lab scale. Results: Analysis of the results (Tukey's test, p < 0.05) showed that the control group produced a greater color change (p < 0.05) in seven and fourteen days in the A2 shade. The B2 shade, in fourteen days, showed a greater color change (p < 0.05) for the specimens immersed in tomato sauce with no statistical difference (p > 0.05) of the control. For the C2 shade, the specimens immersed in tomato sauce presented a greater color change (p < 0.05) at seven days. Conclusion: It could therefore be concluded that there is a significant interaction between the composite resin and pigment agents. All pigmented substances produced color changes in the composite resin.

Applicability of knowledge of graduates in dentistry: use of irreversible hydrocolloid / Aplicabilidad del conocimiento de licenciados en odontología: el uso de hidrocoloide irreversible

The objective of this study was to evaluate the knowledge applied by dental students on the procedures of disinfection, tempering and pouring of irreversible hydrocolloid impressions. This study was conducted through a questionnaire to 86 undergraduate students, of both genders, of the eighth and ninth period of the School of Dentistry, Pontifical Catholic University, Belo Horizonte, MG. The questionnaire contained 12 multiple choice questions about clinical and laboratory procedures for dental impression. Analyzed data were descriptively and qualitatively. Most subjects (70%) stated they did disinfection of dental impression with 1% sodium hypochlorite spray. However, they did it in open containers (75.4%) and with time control (68.6%). The ratio water / powder is randomly conducted by most students (60.5%), and tap water is the one most commonly used (95.3%). The mixing of the calcium sulfate is done manually by nearly all students (97.7%), and use vibrator during the pouring of the calcium sulfate is common among undergraduates (60.5%). The setting of the calcium sulfate takes place predominantly exposed to air (93%) and the removal of the model is made ??between 30 and 60 min after pouring by 84.9% of students. These results point to the need for awareness of students of adopting practices transmitted during the undergraduate degree. It is also necessary to investigate the possible causes of knowledge transmission problems and how to effectively adopt good clinical practices.

El objetivo fue evaluar el conocimiento aplicado por estudiantes de odontología en los procedimientos de desinfección, templado y vaciado de las impresiones de hidrocoloides irreversibles. Este estudio se llevó a cabo a través de un cuestionario a 86 estudiantes de pregrado, de ambos sexos, del octavo y noveno período de la Escuela de Odontología de la Pontificia Universidad Católica, Belo Horizonte, MG. El cuestionario contenía 12 preguntas de opción múltiple acerca de los procedimientos clínicos y de laboratorio para impresión dental. Los datos fueron analizados de manera descriptiva y cualitativa. La mayoría de los sujetos (70%) declararon que hicieron desinfección de la impresión dental con pulverización de hipoclorito de sodio al 1%. Sin embargo, lo hicieron en recipientes abiertos (75,4%) y con un control de tiempo (68,6%). La relación agua/polvo se realizó de manera aleatoria por la mayoría de los estudiantes (60,5%), utilizando principalmente agua del grifo (95,3%). La mezcla del sulfato de calcio se realiza manualmente por casi todos los estudiantes (97,7%) y el uso del vibrador durante el vertido del sulfato de calcio es común (60,5%). El ajuste del sulfato de calcio tiene lugar predominantemente en exposición al aire (93%), la remoción del modelo se hace entre 30 y 60 min después del vaciado por un 84,9% de los estudiantes. Estos resultados apuntan a la necesidad de que los estudiantes tomen conciencia de las prácticas transmitidas durante la licenciatura. También es necesario investigar las posibles causas de los problemas de transmisión de conocimiento y cómo aplicar efectivamente las buenas prácticas clínicas.