Objectives: The aim of the present investigation was to evaluate tensile bond strength of a new self-conditioning dentin adhesive system (Xeno III) compared to two established dentin bonding agents (Excite, Syntac) in combination with different composite materials in vitro. Methods: Sixty freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 1.5 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups: group A: Xeno III/ Esthet X, group B; Xeno III/ QuiXFil; group C: Excite/ Tetric; group D: Syntac/ Tetric. Tensile bond strength of the above mentioned adhesive agents was measured 15 minutes after application and light curing of the composite material (colour A2) using an universal testing machine. Results: For the four test series following tensile bond strengths were evaluated (mean value and standard deviation in MPa): group A 6.90 (± 1.29), group B 7.48 MPa(± 1.53), group C 4.73 (± 0.87) and group D 3.87 (± 0.54). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (p Conclusions: Regarding the limitations of an in vitro study it can be concluded that the self-conditioning dentin adhesive system showed favourable results. Therefore, Xeno III might be a good alternative in clinical practice compared to the other materials tested. Palabras clave: dentin, dentin bonding agent, bond strength