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

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)

Microhardness and surface roughness of Biodentine exposed to mouthwashes.

Aim: This study evaluates Vickers microhardness and surface roughness in Biodentine cement (M1) and glass-ionomer cement Fuji IX (M2), both immersed in mouthwash. Materials and Methods: Fifty-four samples were randomly distributed in distilled water (S1), Listerine Cool Mint (S2), and Colgate Plax (S3). Each sample was put in a flask with mouthwash for 2 min, under vibration, twice a day for 21 days. Microhardness and surface roughness were assessed at 48 h (T0), 7 days (T1), 14 days (T2), and 21 days (T3). Results: For roughness: time (T), solution (S) and material (M), TxM, and SxM and for microhardness: M, TxS, TxM, and SxM were statistically significant. T3, M1, M1T3, and M1S1 presented the highest surface roughness. M2, M1T0, M1T1, M1T2, M1S1, and M1S2 presented higher microhardness. Conclusion: Biodentine showed higher surface roughness for T1, T2, and T3 and higher microhardness for T0, T1, and T2 against Fuji IX. Biodentine presented higher microhardness independently of solution.

Dureza Superficial de Resinas Compostas Nanoparticuladas e Bulk Fill Expostas a Suplementos Nutricionais / Surface Hardness of Composite Resins Nanoparticulate and Bulk Fill Exposed to Nutritional Supplements

Objetivo: Avaliar a microdureza superficial de duas resinas compostas após imersão controlada a dois suplementos nutricionais à base de carboidratos, desenvolvidos para indivíduos que praticam atividade esportiva. Materiais e Métodos: Utilizou-se as resinas compostas Filtek Z350 XT (3M ESPE); Filtek bulk Fill (3M ESPE) ambas na cor A3. Foram confeccionados 60 corpos- -de-prova, 30 para cada material restaurador, os quais foram divididos nos seguintes grupos: Grupo 1 - controle; Grupo 2 ­ imersão em 20 mL de Gatorade (AmBev) durante 5 minutos 3 vezes por dia; Grupo 3 - imersão em 30 g de gel de carboidrato Carbo Gel (Vox Suplementos) durante 5 minutos 3 vezes por dia. Em todos os grupos o período de reposição foi de 15 dias. Durante os intervalos, as resinas ficaram armazenadas em saliva artificial a 37º C. Foi realizado o teste de microdureza Vickers com base na norma ISO 4049 com o auxílio de um Microdurometro Vickers - Buehler - Lake Bluff, Illinois/USA (MMT-3) com a carga de 50 gf por 30 segundos, foram realizadas 5 endentações por corpo-de-prova, uma no centro e quatro nas periferias. A média dos valores de dureza foi comparada usando o teste ANOVA e o pós-teste de Tukey, em nível de significância de 5,0%. Resultados: Todos os corpos de prova que ficaram imersos em Gatorade e Gel de carboidrato apresentaram valores de microdureza estatisticamente menores, quando comparados aos grupos controle. Conclusão: A imersão de resinas compostas em suplementos alimentares Gatorade (Ambev) e Carbo Gel (Vox Suplementos) diminui significativamente sua dureza superficial.

Objective: To evaluate the surface microhardness of two composite resins when exposed to two nutritional supplements based on carbohydrates developed for sports activity. Materials and Methods: Filtek Z350 XT composite resins (3M ESPE) were used; Filtek bulk Fill (3M ESPE) both in color A3. Sixty specimens were prepared, 30 of which were for each restorative material, divided into the following groups: Group 1 (control); Group 2 - immersion in 20 mL of Gatorade (AmBev) for 5 minutes 3 times per day; Group 3 - immersion in 30 g Carbo Gel Carbohydrate Gel (Vox Supplements) for 5 minutes 3 times a day, the process was repeated for 15 days. The Vickers micro hardness test was performed based on ISO 4049 with the aid of a Vickers - Buehler - Lake Bluff, Illinois / USA (MMT - 3) Microduometer with a load of 50 gF for 30 seconds. Performing 5 indentations per body of evidence, one in the center and four in the peripheries. Data were submitted to analysis of statistical variance ANOVA, followed by Tukey test at a level of 5.0% of significance. Results: All specimens that were immersed in Gatorade and Carbohydrate Gel had statistically lower microhardness values when compared to the control group. Conclusions: The use of Gatorade (Ambev) and Carbo Gel supplements (Vox Supplements) decreased the surface hardness of the studied resins.