Objective: This study was to test Dentin bond strength at different time intervals ( 24 hours, one month and three months) of a recent self adhesive flowable composite compared to two step self etch system and one step self etch system. Materials and Methods: a total of 27 freshly extracted sound human permanent molars were utilized in this study to prepare one hundred and eight specimens for microshear bond strength test (each tooth was used to prepare 4 specimens).Each molar was prepared by removal of the occlusal enamel parallel to the occlusal plane exposing the superficial dentin. Translucent micro-catheters were used, The micro-catheters were sectioned into small micro-tubules of one mm height. Each tubule was placed just pulpal to the dentino-enamel junction An endodontic plugger was then used to pack the material into the tubule. Data were statistically analyzed. Results: The two step self etch system showed the highest microshear bond strength values followed by the one step self etch system, while the self adhesive flowable composite showed the lowest values, there was statistically significant difference between the two step self etch system and the one step self etch system, but there was no significant difference between the one step self etch system and the self adhesiveflowable composite among the three tested durations. Conclusions: 1.The new self etch – self adhesiveflowable composite can be used as an alternative to the one step self etch restorative systems.2. The chemistry and filler loading had a dramatic effect on the adhesive properties of the restorative systems investigated.3. Improved bonding of restorative systems to dentin does not necessarily improvement of bond strength.4.Bond strength durability was maintained for all tested restorative systems up to three months.