The aim of the this prospective, randomised blinded study was to compare the clinical performance of two Adhesive Systems (Excite and AdheSE, Ivoclar Vivadent, Schaan, Liechtenstein) in combination with Tetric Ceram HB over a period of twelve month. A total of 100 class I (27 teeth) and II (73 teeth) restorations were placed in molars and premolars in 50 patients in this prospective study. At each patient one filling was placed using AdheSE and Excite. The fillings were placed under rubber dam according to the manufactures instruction. Evaluations took place at baseline, 6, 12, 24 and 48 months based on the modified Ryge criteria by a blinded dentist. 60 restorations could be observed all five recalls (Excite: 30, AdheSE: 30). One filling in each group had to be replaced due to filling fracture. None of the fillings showed signs of secondary caries. Except for the criteria "marginal adaptation" all other criteria showed no significant differences between baseline and the four year recall (p Keywords: Bonding, Kompositfüllung, Dentinhaftvermittler, klinische Studie, Kavitätenklasse I und II