The aim of this prospective study was to evaluate the clinical performance of the selfetch adhesive AdheSE One (Ivoclar Vivadent) in combination with the composite Tetric Evo Ceram (Ivoclar Vivadent) for class I and II restorations. The improvement of the marginal adaptation with the additional use of a flowable resin composite (Tetric Flow, Ivoclar Vivadent) for cavity lining was tested. In accordance with a split mouth design, 50 patients received 100 restorations in premolars and molars. A total of 25 class I and 75 class II cavities were restored. Each restoration was scored according to the modified Ryge criteria at baseline, after 6 and 12 months. After 1 year (recall rate 100%) the results of the Ryge evaluation for both groups with/ and without application of Tetric Flow were: marginal adaption: Alpha: 47/47, Bravo: 3/2, Charlie: 0/1; marginal discoloration: Alfa: 49/47, Bravo: 1/3; color match: Alfa: 49/48, Bravo: 1/1, Charlie: 0/1; filling integrity: Alfa: 48/50, Bravo: 2/0. All restored teeth remained vital, the parameter hypersensitivity, recurrent caries, surface and proximal contact were scored Alfa for all teeth. Between both groups no statistical significant differences could be detected (Mann- Whitney- U- Test, p Keywords: klinische Studie, niedrigvisköse Komposite, selbstkonditionierendes Adhäsiv, Ryge-Kriterien