Influence of Surface Sealants on Microleakage in Composite Restorations / Estudio de la Influencia de los Sellantes de Superficie sobre la Microfiltración en Restauraciones de Composite

ABSTRACT: Polymerization shrinkage of composites can generate stress that results in the formation of microgaps at the resin-enamel interface and marginal leakage. The aim of the present work was to evaluate the influence of surface sealants on microleakage in composite restorations. Enamel-dentin occlusal cavities were prepared in 30 non-carious upper and lower premolars. The cavities were restored with One Coat Bond SL and Brilliant New Generation (Coletene), following the manufacturers' instructions, and polished appropriately. The samples were randomly assigned to one of the following six treatment groups: Group I (Control-no sealant); Group II: Single Bond (3M/ESPE); Group III: Perma Seal (Ultradent); Group IV: Heliobond (Vivadent); Group V: Biscover LV (Bisco); Group VI: Bioforty (Biodinâmica). The samples were then immersed in 2 % aqueous methylene blue solution for 48 hours, and thermocycled 100 times from 5 ºC to 55 ºC. The obtained specimens were ground in a bucco-palatal orientation to reach the medial plane, and observed under a stereoscopic loupe at 40X. The degree of microleakage was evaluated by assessing the penetration of the dye to the tooth-restoration interface, using a 0 to 3 grading scale. The obtained data were analyzed using the Kruskal-Wallis non-parametric test. Significant differences were observed between all rebonded groups and the control group; no differences were observed among Single Bond, Perma Seal and bioforty, or between Heliobond and Biscover LV. It would seem convenient to apply a surface sealant over composite restorations to improve marginal integrity and reduce microleakage.

RESUMEN: La contracción de polimerización de los composites puede generar fuerzas que determinan la formación de microbrechas en la interfase resina-esmalte y filtración marginal. El objetivo de este trabajo fue evaluar la influencia de los sellantes de superficie, en restauraciones de composite, sobre la microfiltración. Se utilizaron 30 premolares superiores e inferiores, libres de caries, donde se realizaron preparaciones oclusales amelodentinarias que fueron obturadas con One Coat Bond SL y Brilliant New Generation (Coletene), siguiendo las indicaciones del fabricante y pulidas adecuadamente. Luego las muestras se distribuyeron aleatoriamente en seis grupos, según los materiales experimentales: Grupo I (Control), Grupo II: Single Bond (3M/ESPE), Grupo III: Perma Seal (Ultradent), Grupo IV: Heliobond (Vivadent), Grupo V: Biscover LV (Bisco), Grupo VI: bioforty (biodinámica). Posteriormente las piezas fueron sometidas a ciclaje térmico por 100 ciclos entre 5 ºC y 55 ºC, sumergidas en una solución acuosa de azul de metileno al 2 % durante 48 horas y desgastadas en sentido V-P, hasta el plano medial, para ser observadas con lupa estereoscópica a 40 X. El grado de filtración se evaluó por la penetración del colorante en la interfase diente-restauración en una escala de O a 3. Los datos obtenidos fueron analizados mediante la muestra no paramétrica de Kruskal-Wallis. Se encontraron diferencias significativas de todos los grupos con respecto al grupo control (p= 0,0167), no existiendo significación entre Single Bond, Perma Seal y bioforty ni entre Heliobond y Biscover LV. En restauraciones de composite, sería conveniente la aplicación de sellantes de superficie para mejorar la integridad marginal y disminuir la microfiltración.

Effect of Sealant Application and Thermal Cycling on Bond Strength of Tissue Conditioners to Acrylic Resin

The aim of this study was to evaluate the effect of sealer application and thermal cycling on the bond strength between tissue conditioners and acrylic resin, and to observe the type of bond failure. Two hundred eighty-eight specimens (10x16x3 mm) were made of an acrylic resin (Lucitone 500, Dentsply) using a metal muffle. Specimens were divided into four groups according to the tissue conditioner (Coe-Comfort, GC or Dentusoft, Densell) used and whether or not a sealer (Eversoft Soft Liner Sealer, Myerson) was applied. Each of the four groups was subdivided into other six subgroups (n=12) to undergo thermocycling for 45, 90, 135, 180 or 210 cycles with a dwell time of 60 s, or to be left non thermocycled (control). Tensile bond strength was measured in a universal testing machine at a crosshead speed of 5 mm/min. Sealant application had no effect on the tensile bond strength of the relined acrylic resin, regardless of the tissue conditioner used (Coe-Comfort: p=0.306 and Dentusoft: p=0.1501). The number of thermal cycles had a significant effect on the tensile bond strength of the relined acrylic resin (Coe-Comfort: p=0.002 and Dentusoft: p<0.001). Both tissue conditioners presented similar bond strength to acrylic resin. For both tissue conditioners, sealer coatings had no influence on bond strength, while different numbers of thermal cycles affected that mechanical property.

Os objetivos deste estudo foram avaliar o efeito da aplicação de selante e a ciclagem térmica na resistência de união entre condicionadores de tecido e resina acrílica e observar o padrão de fratura. Duzentos e oitenta e oito espécimes (10×16×3 mm) de resina acrílica (Lucitone 500, Dentsply) foram confeccionados utilizando-se uma mufla metálica. Os espécimens foram divididos em quatro grupos de acordo com o condicionador de tecido (Coe-Comfort, GC ou Dentusoft, Densell) e com o uso ou não de selante (Eversoft Soft Liner Sealer, Myerson). Cada um dos quatro grupos foi subdividido em seis grupos para a realização de 45, 90, 135, 180 ou 210 ciclos térmicos, ou ausência de termociclagem (controle). Resistência de união por tração foi mensurada em uma máquina universal de ensaios com velocidade de 5 mm/min. A aplicação de selante não afetou a resistência de união por tração da resina acrílica reembasada, independentemente do condicionador de tecido utilizado (Coe-Comfort: p=0,306 e Dentusoft: p=0,1501). O número de ciclos térmicos apresentou efeito significativo na resistência de união por tração da resina acrílica reembasada (Coe-Comfort: p=0,002 e Dentusoft: p<0,001). Ambos os condicionadores de tecidos apresentaram resistência de união semelhante à resina acrílica. Para ambos os condicionadores de tecidos, a aplicação de selante não apresentou influência na resistência de união, enquanto que diferentes números de ciclos térmicos afetaram essa propriedade mecânica.

Efeito de dois selantes de superfície na alteração colorimétrica de uma resina composta / Effect of two surface sealants on color alteration of a composite resin

Objetivo: avaliar a variação de cor entre superfícies tratadas com agentes químicos de acabamento e polimento. Métodos: Foram utilizadas resina Fill Magic (Vigodent®, Rio de Janeiro, Brasil), A2 (n=18) e A3,5 (n=18). As amostras foram fotopolimerizadas, registrado os valores de L*a*b* através da análise em um colorímetro, posteriormente, foi aplicado uma camada de selantes de superfície, BisCoverTM LV (Bisco Inc, Schaumburg, USA) e Fill Glaze (Vigodent®, Rio de Janeiro, Brasil) e novamente averiguado os valores de L*a*b*. Para o grupo controle não houve tratamento, sendo registrado os valores de L*a*b* em dois tempos distintos. Os valores referentes a varialção de cor foram submetidos à análise de variância (ANOVA) e posteriormente ao teste de Tukey. Resultados: Não houve alteração colorimétrica utilizando o selante BisCoverTM LV sobre a resina A2 e A3,5 (p>0,05). Entretanto, houve alteração colorimétrica quando utilizado Fill Glaze sobre a resina A2 e A3,5 (P=0,0021 e p=0,0020, respectivamente). Conclusão: O selante de superfície BisCoverTM LV não apresentou alteração colorimétrica, sendo ideal para utilização em restaurações estéticas em que a cor da resina deve ser mantida.

Objective: To evaluate the alteration of color (DE) among surfaces treated with liquid finish and polish system. Method: Was used Fill Magic (Vigodent®, Rio de Janeiro, Brasil), A2 (n=18) and A3.5 (n=18) composite resins. The specimens were polymerized, and was registered L*a*b* values using a colorimeter, then two surface sealants was applied: BisCoverTM LV (Bisco Inc, Schaumburg, USA) and Fill Glaze (Vigodent®, Rio de Janeiro, Brazil) and was registered L*a*b* values. For the control group was not applied surface sealant, and L*a*b* values was registered in two different moments. The DEab* values were submitted to the analysis of variance (ANOVA) and then to the Tukey test. Results: Was not observed color alteration using BisCoverTM LV in both resins A2 and A3.5 (p>0.05). However, was observed color alteration when was used Fill Glaze, in both resins A2 and A3.5 (p=0.021 and p=0.002, respectively). Conclusion: In two tested composite resins colors, the surface sealant BisCoverTM LV presented no color alteration, ideal to application in esthetic restoration, when the color should be maintaining.

Effect of resin sealants on the reduction of microleakage in composite restorations / 대한치과보존학회지

The purpose of this study was to compare the ability of three resin surface sealants to prevent microleakage in Class V composite resin restorations. Forty Class V cavities with the occlusal margin in enamel and gingival margin in dentin were prepared on the buccal surfaces of sound extracted molars, and restored with composite resin. Restorations were randomly assigned into one of four equal groups (n = 10): a control group, without resin sealing, and three experimental groups in which margins were sealed with Fortify Plus, Biscover and Permaseal, respectively. Specimens were thermocycled, immersed in a 2% methylene blue solution for 4 hours, sectioned longitudinally, and observed the leakage at the occlusal and gingival margins. The result was analyzed using Kruskal-Wallis test, Mann-Whitney test and Wilcoxon signed rank test. In conclusion, the ability to reduce microleakage at occlusal margins was similar in all of three sealants. However at gingival margin, it depended on the type of used resin surface sealant. At gingival margin, control and Fortify Plus group showed statistically higher microleakage than PermaSeal group, and Fortify Plus group also showed higher microleakage than BisCover group (p < 0.05).