In vitro microleakage of three adhesive systems with three different solvents

Resumen

Micro-leakage can be described as the movement of bacteria, fluids, molecules, ions or air between the wall of the tooth cavity and the restorative material. This elicits clinical consequences such as sensitivity, discoloration in the internal phase between tooth and restorative material, secondary caries and pulp disease. The aim of this study was to quantify micro-leakage in  dentin and enamel margins in class V cavities of extracted teeth restored with composite resin, using a bonding system provided by different solvents. An experimental study was conducted in 30 molars, extracted no longer than 3 months before. These molars were free of caries and with intact crown surface. Standard class V cavities were shaped, on lingual and vestibular surfaces, with margins in the enamel.  Specimens were randomly assigned to three groups, according to their corresponding bonding system. The following bonding systems were applied: Prime & Bond NT, single Bond, and classic Syntec. Manufacturers  instructions were closely adhered to. Cavities were restored with  ceromer. After being finished and polished, specimens were subjected to thermo-cycling process, and later nail polish and wax were applied. After this procedure, samples were immersed in methylene blue for 24 hours. Using a diamond disk, specimens were then longitudinally sectioned. Samples were evaluated with a microscope, using a 0-4 scale. Data were analyzed  using a relative frequency distribution test. The study reached the conclusion that none of the used systems was able to prevent micro-leakage.