Objective: The current study investigated the effect of using antibacterial MDPB containing and/or fluoride releasing self-etch adhesive systems on early bond strength and sealing ability of composite restoration to primary tooth dentin. Four self-etch adhesive systems; from the same manufacturer, were used: two; two-step (Fluoride-free adhesive [Clearfil SE Bond] and antibacterial MDPB containing and fluoride-releasing adhesive [Clearfil Protect Bond]) and two; one-step (Fluoride-free adhesive [Clearfil S3 Bond] and fluoride-releasing adhesive [Clearfil S3 Bond Plus]). Resin-dentin interface of these adhesives was also investigated. Materials and Methods: A total of 48 sound primary molars were collected for this study. For microshear bond strength, the occlusal surface of sixteen caries free primary molars imbedded in cylindrical acrylic models was prepared into flat dentinal surfaces. Teeth were randomly assigned into four equal groups corresponding to adhesive systems used. A low viscosity luting composite resin (Clearfil Majesty Flow) was used for composite mycrocylinder construction (1 mm in diameter and 2 mm in height). Two composite microcylinders were constructed on each dentin surface (S = 8 per group). A Lloyd universal testing machine was used to test the microshear bond strength at a crosshead speed of 0.5 mm/min. For microleakage test, standardized Class V cavities were prepared onto the buccal side of thirty-two caries free primary molars, with gingival margin at the CEJ. The teeth were randomly divided into four equal groups corresponding to adhesive systems used (L= 8 per group). Cavities were restored with a low viscosity luting composite resin (Clearfil Majesty Flow), finished and polished. Specimens were stored in water at room temperature for 24 hours, then thermocycled between 5º – 55° C (± 2° C) for 500 cycles with a dwell time of 15 seconds before they were immersed in 2% methylene blue solution for 24 hours. Teeth were sectioned and dye penetration was examined under a stereomicroscope. Two additional samples per each group were processed for scanning electron microscopic (SEM) observations. Data were statistically analyzed by Mann-Whitney U tests and Tukey’s post-hoc test (p < 0.05). Results: In results, the microshear bond strength varied from 24.5±6.65 MPa for the fluoride-free two-step adhesive to 17.08 (±3.7) MPa for the antibacterial fluoride-releasing two-step adhesive, the latter being the only one that showed significantly lower bond strength value compared to the fluoride-free two-step and the fluoride-releasing one-step adhesives. On the other hand, there was no statistically significant difference in the degree of microleakage comparing the fluoride-free and fluoride-releasing adhesives. However, the sealing ability of two-step adhesives was better than one-step adhesive systems. SEM showed hybrid layer and resin tag formations in groups of mild two-step adhesives, whereas with milder one-step adhesives; their interaction with the underlying dentin was rather superficial with little or no resin tag formation. Conclusion: All the adhesive agents evaluated showed optimal shear bond strength of 17-20 Mpa. The presence of antibacterial (MDPB) and/or fluoride-releasing component in the self-etch adhesive systems might not adversely affect the bond strength or sealing ability of these adhesives to primary teeth dentin, except for the dentin bond strength of two-step self-etch adhesive system. There is a clear correlation between the pH of adhesive system and the depth of interaction with dentin.