RESUMEN
An in vitro study was conducted to compare microleakage in nanohybrid composite restorations in Class V cavities using total etch and self-etch adhesives and two different horizontal layering techniques. Cavities were made on buccal and lingual surfaces of forty extracted premolar teeth and divided into groups A and B containing buccal surface cavities treated with total etch adhesive system and lingual surface cavities treated with Single step adhesive respectively. Cavities were restored using nanohybrid composite and randomly divided into four subgroups depending on incremental technique used. Specimens were then immersed in methylene blue dye for 24 hours and analysed under stereomicroscope for dye penetration. Results indicated microleakage with all groups with total etch group showing superior results than self etch group and group in which occlusal increment was placed first showing superior results than group with gingival increment placed first.