The aim of the present study was to evaluate the influence different bleaching agents and concentrations on microtensile bond strength of different dentin adhesives in class V cavities. 135 freshly extracted third molars were included in this study. In all teeth cervical class V dentinal cavities were prepared allowing the simulation of dentin perfusion. The specimens were randomly assigned to nine experimental groups of fifteen each: S0: Syntac/ control; S17: Syntac/ Perfect Bleach 17%; S38: Syntac/ Opalescene Xtra Boost 38%; X0: XP Bond/ control; X17: XP Bond/ Perfect Bleach 17%; X38: XP Bond/ Opalescene Xtra Boost 38%; A0: AdheSE One/ control; A17: AdheSE One/ Perfect Bleach 17%; A38: AdheSE One/ Opalescene Xtra Boost 38%. Bleaching was performed 8 hours at 36°C for 7 days. Between the ranges all samples were stored in physiological saline for 16 hours. The dentin adhesives used as recommended by manufactures instruction were applied on a standardized dentin surface. Microtensile bond strengths of the above mentioned bonding agents was measured using a universal testing machine. For the nine test series following tensile bond strengths were evaluated (mean values and standard deviations in MPa): GroupS0S17S38X0X17X38A0A17A38 Microtensile bond strength25,8921,4417,0822,1518,9914,6124,3318,9717,29 ±2,972,051,943,532,962,246,942,795,78 Schlagwörter: Dentinadhesive, Mikrozugfestigkeit, Bleichtherapie, dentin adhesive, microtensile bond strength, Tooth bleaching