The aim of this study was to evaluate the experimental nanocomposite (Kelfil) against microleakage when bonded with two different types of bonding systems. Methods: Sixty sound extracted human permanent incisors were divided into six groups randomly. Each tooth was prepared with standardised Class III cavity on each proximal surface. The teeth were immersed in Rhodamin B dye for ten hours and sectioned to analyse the depth of dye penetration. The depth of the dye penetration was measured in micrometres by using confocal laser scanning microscope (CLSM). Results: The depth of the dye penetration in the groups was compared by ANOVA test. The results showed comparable microleakage between different types of composites. Conclusion: The experimental nanocomposite (Kelfil) in comparison to the commercially available nanocomposite and micro-hybrid composite has comparable microleakage when bonded using self-etching and total-etched adhesive systems.