A study was developed to compare the marginal leakage by basic fuchsin dye, around cervical restorations after applying composite resin + dentin adhesive and composite resin + glass ionomer cement. Cervical cavities were prepared on the lingual and vestibular surfaces in 19 freshly extracted human teeth. The lingual cavities were restored with composite resin + dentin adhesive, and the vestibular cavities were restored with composite resin + glass ionomer cement ("Sandwich's" technique). After placement of each restoration, these teeth were thermocycled, immersed in dye solution. After removal from the dye, the teeth were sectioned through the restorations, along the long axis of the crown, and analyzed the leakage's degree. The composite resin + glass ionomer cement restorations, showed marginal leakage between the restorative material and the cervical margin but, generally since the middle of this wall.