The aim of the present investigation was to evaluate microtensile bond strength of four self-conditioning dentin adhesive systems (Xeno III, Clearfil SE Bond, Clearfil Protect Bond, Futurabond NR) in combination with a light-curing composite material (Clearfil AP-X) 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; group B; Clearfil SE Bond; group C: Clearfil Protect Bond; group D: Futurabond NR. All materials were applied on a surface area of 0.785mm² as recommended by the manufacturer. Microtensile bond strength (µ-TBS) of the above mentioned adhesive systems was measured 15 minutes after application and light curing of the composite material (colour A2) using an universal testing machine. Statistical analysis was performed using SPSS 10.0. Results: For the four test series following microtensile bond strengths were evaluated (mean value and standard deviation in MPa): group A 27.29 (± 4.16), group B 32.23 MPa(± 5.56), group C 19.57 (± 2.80) and group D 35.62 (± 3.97). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (pConclusions: Regarding the limitations of an in vitro study it can be concluded that all self-conditioning dentin adhesives showed promising results. Therefore, the clinical use of self-conditioning adhesive systems might be a good alternative to the established total-etch systems. Schlagwörter: dentin, dentin adhesive, bond strength, dentin bonding, self-conditioning