Abstract Objective – The objective of the study was to evaluate the amount of microleakage occurring at the interface of different restorative materials and tooth surface in a class II restoration. Materials & methodology-- 30 freshly extracted non carious premolars extracted for orthodontic reasons were taken. Class II slot cavities were prepared & restored with Resin composite, Polyacid modified resin composites, Resin modified Glass ionomer cement both mesially & distally. Protective coating (G-Coat plus) is applied on one side of tooth above the restoration according to manufacturer’s instructions. All the samples underwent thermocycling for 500 cycles following which they are placed in methylene blue dye for 24 hours. Teeth were sectioned by a diamond saw through the centre of restorations and viewed under stereomicroscope to evaluate the amount of dye penetration. Results -- Reduction in Microleakage was seen with protective coating when compared to samples without coating. With in the types of restorations Resin modified Glass ionomer cement showed least microleakage followed by Polyacid modified resin composites and Resin composite.