Objective: The aim of this prospective long-term 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. Methods: In accordance with a split mouth design, 50 patients received 100 restorations in premolars and molars. A total of 32 class I and 68 class II cavities were restored. After using the adhesive system AdheSE One, in group T the restorations were placed with Tetric Evo Ceram and in group TF there was applied an additional layer of the flowable composite before placing the restoration also with Tetric Evo Ceram. Each restoration was scored according to the modified Ryge criteria at baseline, after 6, 12, 24 and 36 months. Results: After 36 months (recall rate 80%) the results of the Ryge evaluation for both groups without/ and with application of Tetric Flow were: marginal adaption: Alpha: 34/35, Bravo: 2/5, Charlie: 1/0, Delta: 1/0; marginal discoloration: Alfa: 30/36, Bravo: 8/4; filling integrity: Alfa: 37/39, Bravo: 1/1. All restored teeth remained vital, the parameter hypersensitivity, recurrent caries, surface, colour match and proximal contact were scored Alfa for all teeth. Between both groups no statistical significant differences could be detected (Mann- Whitney- U- Test, p0,05). The cumulative failure rate was 7,7% for group T and 0% for group TF. Conclusion: After 36 months clinical use of AdheSE One in stress-bearing posterior cavities reached acceptable clinical results in both groups. Schlagwörter: clinical study, selfetch adhesive, flowable composite, ryge criteria, composite resin