RESUMO
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