Effects of LED Lights on Bulk Fill Resin Polymerization

The present study analyzed the microhardness and degree of conversion of three Bulk Fill resins (M1 - Filtek Bulk Fill; M2 - Tetric N-Ceram Bulk Fill and M3 - Opus Bulk Fill) polymerized by single peak and polywave Light-emitting Diode Curing Lights. A total 90 test specimens (n=10) were obtained using a Teflon matrix for the purpose of testing microhardness; and for degree of conversion: 135 specimens (n=5) by using a 2 x 6 cm matrix. The specimens were light polymerized using 3 light sources (L1 - Optilight Max, L2 - Bluephase, L3 - VALO). They were kept in artificial saliva om an oven at 37±1°C during the experiment. The degree of conversion was measured by FTIR 24 h after obtaining each test specimen. The microhardness readouts were performed with a microdurometer at the time intervals of 48 hours (T0), 7 days (T1), 14 days (T2) and 21 days (T3). M1L3 was found to show the highest microhardness values in T2, and M1 showed the lowest degree of conversion in the deep third with L1. It was concluded that Filtek Bulk Fill resin showed the best results in comparison with the other resins.

El presente estudio analizó la microdureza y el grado de conversión de tres resinas Bulk Fill (M1 - Filtek Bulk Fill; M2 - Tetric N-Ceram Bulk Fill y M3 - Opus Bulk Fill) polimerizadas por lámparas de curado de diodo emisor de luz de pico único y polionda. Se obtuvieron un total de 90 especímenes de prueba (n=10) utilizando una matriz de teflón con el propósito de probar la microdureza; y para grado de conversión: 135 especímenes (n=5) utilizando una matriz de 2 x 6 cm. Las muestras se fotopolimerizaron utilizando 3 fuen- tes de luz (L1 - Optilight Max, L2 - Bluephase, L3 - VALO). Se mantuvieron en saliva artificial en estufa a 37 ±1°C durante el experimento. El grado de conversión se midió por FTIR 24 h después de obtener cada muestra de prueba. Las lecturas de microdureza se realizaron con un microdurómetro en los intervalos de tiempo de 48 horas (T0), 7 días (T1), 14 días (T2) y 21 días (T3). Se encontró que M1L3 mostraba los valores más altos de microdureza en T2, y M1 mostraba el grado más bajo de conversión en el tercio profundo con L1. Se concluyó que la resina Filtek Bulk Fill mostró los mejores resultados en comparación con las demás resinas.

Changes in the properties of bulk-fill resins under conditions of gastroesophageal reflux and bulimia

Aim: Evaluate the roughness, microhardness and color change of different Bulk Fill resins when submitted to the condition of gastroesophageal reflux and bulimia. Methods: 60 specimens (n = 10) of Bulk-Fill composite resins were made: M1 ­ Filtek™; M2 ­ Tetric N-Ceram and M3 ­ OPUS, through a matrix 2x6 mm and light cured by the VALO light source. After polishing, initial analyzes (48 hours - T0) of surface roughness (Ra), microhardness (VHN) and color change (ΔE) were performed. To simulate the oral condition of severe gastroesophageal reflux and bulimia, the specimens were immersed in hydrochloric acid (S1) (pH 1.7) 4 minutes a day, for 7 days. Control group specimens were immersed in artificial saliva (S2). Subsequently to immersions, mechanical brushing was performed for 3 minutes, three times a day, simulating 7 days of brushing. And again, the analyzes of Ra, VHN and ΔE were performed (7 days - T1). Thus, hydrochloric acid immersion, mechanical brushing and Ra analysis were repeated at 14 days (T2) and 21 days (T3); and T2, T3 and T4 (3 years) for VHN and ΔE. Results: After Shapiro-Wilk statistical test, ANOVA and Tukey test with Bonferroni adjustment (p>0.05), M3 showed the lowest Ra at all times compared to the other resins, while the highest Ra was at T0. M1 and T1 showed higher VHN. And M2 and T4 showed higher ΔE. Conclusion: Bulk Fill resins can be indicated for patients with Gastroesophageal Reflux and Bulimia, nonetheless, Tetric N-Ceram resin showed the worst results

Influence of NaHCO3 powder on color and roughness of the composite submitted to bleaching and euterpe oleracea / Influencia del polvo de NaHCO 3 en el color y rugosidad del composite sometido a blanqueo y euterpe oleracea

Aim: This study aims to evaluate the surface roughness and susceptibility to staining of bleached composite resin with 22% carbamide peroxide, as well as the effect of subsequent prophylaxis with NaHCO3 powder. Material and Methods: Forty disk-shaped (2 × 6 mm) specimens of composite resin (Z250 XT) were prepared. Half of the specimens were subjected to bleaching with 22% carbamide peroxide, and the other half were stored in artificial saliva. In sequence, all specimens were immersed in acai juice (Euterpe oleracea) for 4 h for 14 days, and subdivided into two groups. Group 1 samples were subjected to prophylaxis treatment, while group 2 samples were subjected to treatment with artificial saliva. Surface roughness (Ra) and color (ΔE*) were measured after polishing (T0), bleaching (T1), immersion in acai juice (T2), and application of NaHCO3 powder (T3) using a profilometer and a spectrophotometer. Results: Statistical analyses (analysis of variance and Tukey's test, p≤0.05) revealed that regarding color there was statistically significance for the factors in isolation, except for the factor bleaching. For both color and surface roughness there was statistically significant difference for the interaction, except for the interaction between NaHCO3 power and bleaching. Conclusion: The NaHCO3 air-powder polishing decreases the staining of the composite resin; however, it increases the surface roughness. With respect to the color variable, the whitening factor had no significant effect on the tested material; however, it increases surface roughness.

Objetivo: Este estudio tiene como objetivo evaluar la rugosidad de la superficie y la susceptibilidad a la tinción de la resina compuesta blanqueada con peróxido de carbamida al 22%, así como el efecto de la profilaxis posterior con polvo de NaHCO3. Material y Métodos: Se prepararon cuarenta especímenes en forma de disco (2 × 6 mm) de resina compuesta (Z250 XT). La mitad de los especímenes se sometieron a blanqueo con peróxido de carbamida al 22% y la otra mitad se almacenó en saliva artificial. En secuencia, todos los especímenes se sumergieron en jugo de acai (Euterpe oleracea) durante 4h durante 14 días, y se subdividieron en dos grupos. Las muestras del grupo 1 se sometieron a tratamiento profiláctico, mientras que las muestras del grupo 2 se sometieron a tratamiento con saliva artificial. La rugosidad de la superficie (Ra) y el color (ΔE*) se midieron después del pulido (T0), el blanqueo (T1), la inmersión en jugo de acai (T2) y la aplicación de polvo de NaHCO3 (T3) utilizando un perfilómetro y un espectrofotómetro. Resultados: Los análisis estadísticos (análisis de varianza y prueba de Tukey, p≤0.05) revelaron que en relación al color hubo significancia estadística para los factores en forma aislada, excepto para el factor blanqueamiento. Tanto para el color como para la rugosidad de la superficie hubo una diferencia estadísticamente significativa para la interacción, excepto para la interacción entre el poder de NaHCO3 y el blanqueo. Conclusión: El pulido al aire con polvo de NaHCO3 disminuye el manchado de la resina compuesta; sin embargo, aumenta la rugosidad de la superficie. Con respecto a la variable color, el factor de blanqueamiento no tuvo efecto significativo sobre el material ensayado; sin embargo, aumenta la rugosidad de la superficie.

Effect of Color and Surface Roughness of Glass Ionomer Cements Submitted to Solutions Based on Ilex paraguariensis

ABSTRACT: The present study analyzed the color change (DE) and surface roughness (Ra) of glass ionomer cements (GICs) subjected to typical herbaceous South American beverage action - Ilex paraguariensis. 90 specimens (n = 10) were made: M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). After light curing/ polymerization of GICs, specimens were divided for being submitted to solutions for one hour a day for 21 days: S1 - Yerba Mate Pajarito Traditional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Water (control). Four DE and Ra readings were taken: T0 - initial; T1 - 7 days; T2 - 14 days and T3 - 21 days, with a spectrophotometer and a roughness meter respectively. The obtained data were submitted to ANOVA statistical analysis and Bonferroni. S1 and S2 at T1 and T2 there was no statistical difference between the materials, and at T3 Materials M1=M2, M1=M3, and M2>M3. For S3 at T1, T2 and T3 there was no difference between the materials. Analyzing surface roughness, there was no statistical significance. Concluded that all materials changed color with greater influence of time, but without changing surface roughness.

RESUMEN: En el presente estudio se analizó el cambio de color (DE) y la rugosidad superficial (Ra) de los cementos ionómero de vidrio (CIV) sometidos a la acción típica de las bebidas herbáceas sudamericanas - Ilex paraguariensis. Se realizaron 90 especímenes (n = 10): M1 - GIC Riva Light Cure® (SDI); M2 - GIC Riva Self Cure® (SDI); M3 - GIC Vitremer® (3M ESPE). Después de la fotopolimerización/ polimerización de los CIV, los especímenes se dividieron y fueron sometidos a soluciones durante una hora al día durante 21 días: S1 - Yerba Mate Pajarito Tradicional (Pajarito); S2 - Erva Mate Chimarrão (Barão de Cotegipe); S3 - Agua (control). Se tomaron cuatro lecturas de DE y Ra: T0 - inicial; T1 - 7 días; T2 - 14 días y T3 - 21 días, con espectrofotómetro y rugosímetro respectivamente. Los datos obtenidos fueron sometidos a análisis estadístico ANOVA y Bonferroni. S1 y S2 en T1 y T2 no hubo diferencia estadística entre los materiales y en T3 Materiales M1=M2, M1=M3 y M2>M3. Para S3 en T1, T2 y T3 no hubo diferencia entre los materiales. Al analizar la rugosidad de la superficie, no hubo significación estadística. En conclusion, todos los materiales cambiaron de color con mayor influencia del tiempo, pero sin cambiar la rugosidad de la superficie.

Effect of desensitizing dentifrices on eroded dentin wettability / Efeito de dentifrícios dessensibilizantes na molhabilidade da dentina erodida

Objective: To analyze the wettability on the surface of eroded dentin in teeth submitted to abrasive wear with desensitizing dentifrices. Material and Methods: Bovine dentin specimens were polished and immersed in 10 mL of citric acid (pH=3.2) for 2 h. The eroded specimens were submitted to mechanic brushing according to the 4 dentifrices adopted: Colgate Total (control); Colgate Sensitive Pro-Relief; Sensodyne Repair & Protect; or Sensodyne Rapid Relief. Afterwards, it was conditioned in 37% aqueous phosphoric acid solution. Wettability of 80 specimens (n=10) brushed for 7 or 21 days was evaluated by measuring the contact angle between the dentin surface and a drop of the adhesive Single Bond Universal® (3M) with a goniometer. Changes in the surface morphology of 12 specimens (n = 3) brushed for 21 days were followed by confocal laser scanning microscopy (CLSM). Data were analyzed by two-way ANOVA and Tukey test (p > 0.05). Results: Groups treated with desensitizing dentifrices did not differ significantly (p ≤ 0.05). Surface treatment and abrasive wear did not interact significantly (p ≤ 0.05). Brushing along 7 days gave the smallest contact angle value (p ≥ 0.05). CLSM images showed morphological changes for all the groups. Conclusion: The desensitizing dentifrices did not interfere in eroded dentin wettability after brushing along 7 or 21 days. Brushing with any of the dentifrices along 21 days promoted open dentinal tubules.(AU)

Objetivo: Analisar a aplicação de um adesivo na superfície de dentina erodida em dentes submetidos ao desgaste abrasivo com agentes dessensibilizantes. Material e Métodos: Espécimes de dentina bovina foram polidos e imersos em 10 mL de ácido cítrico (pH=3,2) por 2 h. Os espécimes erodidos foram submetidos à escovação mecânica de acordo com os 4 dentifrícios adotados: Colgate Total (controle); Colgate Sensitive Pro-Alívio; Sensodyne Repair & Protect; ou Sensodyne Rápido Alívio. Em seguida, foram condicionados em ácido fosfórico a 37%. A molhabilidade de 80 espécimes (n=10) escovados por 7 ou 21 dias foi avaliada medindo-se o ângulo de contato entre a superfície dentinária com uma gota do adesivo Single Bond Universal® (3M) por um goniômetro. Alterações na morfologia da superfície de 12 espécimes (n = 3) escovados por 21 dias foram seguidos por Microscopia Confocal de Varredura a Laser (MCVL). Os dados foram analisados por ANOVA dois fatores e teste de Tukey (p > 0,05). Resultados: Os grupos tratados com dentifrícios dessensibilizantes não diferiram significativamente (p ≤ 0,05). O tratamento de superfície e o desgaste abrasivo não interagiram significativamente (p ≤ 0,05). A escovação ao longo de 7 dias apresentou o menor valor de ângulo de contato (p ≥ 0,05). As imagens do MCVL mostraram alterações morfológicas para todos os grupos. Conclusão: Os dentifrícios dessensibilizantes não interferiram na molhabilidade da dentina erodida após escovação ao longo de 7 ou 21 dias. A escovação com qualquer um dos dentifrícios ao longo de 21 dias promoveu a abertura dos túbulos dentinários (AU)

Color evaluation of a resin cement light polymerized by different light sources and submitted to potentially staining beverages / Avaliação da cor de um cimento resinoso fotopolimerizado por diferentes fontes de luz e submetidos a bebidas potencialmente corantes

Introduction: The color stability of resin cements, whether dual-pre-cured or photopolymerizable, as well as the color of the dental substrate, are fundamental for the aesthetic success of ceramic restorations, since the ceramic presents a high level of translucency due to its small thickness. Objective: The aim of this in vitro study was to evaluate the color of a resin cement light polymerized by different light sources and immersed in potentially staining beverages. Material and method: Were made 42 specimens of resin cement Variolink-Esthetic (2×6mm) (n=7), being half polymerized with LED light (F1) and half with Halogen light (F2). The specimens were stored in artificial saliva at 37 °C±1 °C. After 24 hours, they were polished with abrasive discs, and divided for the purpose of being submitted to the different solutions for 2 minutes per day, for 28 days, as follows: S1 - Coca-Cola; S2 - Red Wine; and S3 - Distilled Water (Control). Five color readouts were taken: T0 - initial; T1 - 7 days; T2 - 14 days; T3 - 21 days; and T4 - 28 days; with a spectrophotometer (Model SP62S). The color change data (ΔE*) were submitted to statistical analysis, ANOVA and Tukey (p≤0.05). Result: Analyzing the factor solution, S2 (5.89 (±0.02)), produced a higher ΔE* value than S1 (3.79 (±0.02)) and (S1), a higher value than S3 (1.41 (±0.02)). Analyzing the factor light source, F2 (4.05 (±0.12)), produced a higher ΔE* value than F1 (3.33 (±0.12)). When analyzing the factor time, ΔE* values were found to increase gradually over the course of time: T1(2.36 (±0.08)); T2(3.27 (±0.08)); T3(4.06 (±0.08)); and T4(5.09 (±0.08)). Conclusion: It was concluded that red wine produced a greater color change; Halogen light promoted highest degree of pigmentation; and the longer the time of immersion, the greater the color change of the material.

Introdução: A estabilidade de cor dos cimentos resinosos, sejam eles de presa dual ou fotopolimerizáveis, assim como a cor do substrato dental, são fundamentais para o sucesso estético das restaurações cerâmicas uma vez que a cerâmica apresenta alto nível de translucidez devido a sua pequena espessura. Objetivo: O objetivo deste estudo in vitro foi avaliar a cor de um cimento resinoso fotopolimerizado por diferentes fontes de luz e imersos em bebidas potencialmente corantes. Material e método: Foram confeccionados 42 espécimes do cimento resinoso Variolink-Esthetic (2×6mm) (n=7), sendo metade fotopolimerizado com luz LED (F1) e metade com luz Halógena (F2). Os espécimes foram mantidos em saliva artificial à 37 °C±1 °C. Após 24 horas, foram polidos com discos abrasivos e subdivididos para serem imersos 2 minutos por dia, durante 28 dias, nas diferentes soluções: S1 - Coca-Cola; S2 - Vinho Tinto; e S3 - Água destilada (controle). Foram realizadas 5 leituras de cor: T0 - inicial; T1 - 7 dias; T2 - 14 dias; T3 - 21 dias; e T4 - 28 dias; com auxílio de um espectrofotômetro (modelo SP62S). Os dados de alteração de cor (ΔE*) foram submetidos a análise estatística, ANOVA e Tukey (p≤0,05). Resultado: Analisando o fator solução, S2 (5,89 (±0,02)), proporcionou maior ΔE* que S1 (3,79 (±0,02)) e este (S1), maior que S3 (1,41 (±0,02)). Analisando o fator fonte de luz, F2 (4,05 (±0,12)), proporcionou maior ΔE* que F1 (3,33 (±0,12)). E analisando o fator tempo, obteve-se que ΔE* foi gradativamente aumentando no decorrer do tempo: T1(2,36 (±0,08)); T2(3,27 (±0,08)); T3(4,06 (±0,08)); e T4(5,09 (±0,08)). Conclusão: Conclui-se que o vinho tinto promoveu maior alteração de cor; a luz Halógena promoveu maior pigmentação e; quanto maior o tempo de imersão, maior alteração de cor do material.