[Microleakage in class V amalgam restorations lined with and without varnish and dentin bonding agents using different amalgams: An in vitro study]

Microleakage is an important problem for amalgam restorations and causes teeth discoloration, pulp irritation, sensitivity and caries. The aim of this study was to determine and compare the in vitro microleakage of 3 different dental amalgams with commercial names [Cinalux, Dentam, SS White] using a dentin bonding agent [Excite] and a cavity varnish [Compalite], in class V amalgam restorations. Class V preparation measuring 3x2x2 mm were cut on the facial surfaces of 78 freshly extracted human premolar teeth. The teeth were divided into 3 groups of 20 teeth and 2 groups of 9 teeth as positive and negative control. They were restored using the material of choice following manufacture's instructions, and thermocycled between 4+2 C° and 54 +/- 4 C° for 700 cycles in 105 seconds. The teeth were subsequently immersed in methylene blue dye and sectioned to allow assessment of microleakage with stereomicroscope. The obtained data were analyzed by Kruskal-wallis and Mann-whitney U tests. Non-parametric statistical analysis showed significant differences between 3 different amalgams when the cavities lined by Excite [P<0.05]. There was no significant differences between 3 different amalgams when the cavities lined by varnish. These results suggested dentin bonding agents reduced microleakage in comparison to varnish, and the type of amalgam is effective on microleakage

Permeabilidad de barnices cavitarios: estudio in vitro / Permeability of cavity varnishes: in vitro study

Los varnices cavitarios vienen usándose hace tiempo en la profesión odontológica en cavidades operatorias de amalgamas, para disminuir la infiltración marginal debido a la mala adaptación inicial de ellas, y evitar la tinción del diente por la corrosión del metal. Se estudiaron 3 barnices (Copalite, Derfla, Silicate varnish y barniz cavitario Hertz), determinñandose la permeabilidad de ellos a un colorante (azul de metileno 1 por ciento en solución acuosa) medida a la 1ª hora de su aplicación en cavidades simuladas en yeso extraduro saturado con humedad; el grado de permeabilidad fue determinado analizando la penetración del colorante medida en superficie, para cada tipo de material y un grupo control sin barniz. Los valores promedio en mm² de área de infiltración a la 1ª hora fueron de 77.7 para Derfla, 115.6 para Hertz, 127.8 para Copalite, y 127.2 para el grupo Control, encontrándose diferencias estadísticamente significativas entr Derfla y los otros grupos