
Background: Research has been carried out to develop biocompatible restorative materials that can preserve the health of the pulp and maintain the tight seal between the tooth and the restorative material. One of the outcomes of these studies is an alkasite restorative material, Cention N (Ivoclar Vivadent). To check it’s adaptability to Class V cavities compared with the established flowable composites resins that are used routinely to restore class V cavities. Objective: To evaluate micro leakage at enamel-restoration and dentin-restoration interface of class V cavities restored with two different flowable composite resins and new alkasite restorative material-Cention-N. Method: Thirty Class V tooth preparations were divided into three groups of ten cavities each(n=10): Group-I restored with alkasite material- Cention-N (Ivoclar Vivadent), Group-II restored with micro hybrid flowable composite resin- Tetric-N-Flow (Ivoclar Vivadent) and Group-III restored with nanohybrid injectable composite resin- Gaenial Universal Flo (GC, Tokyo). All samples were subjected to 200 themocycles between temperature baths at 50 C and 550 C. The teeth were sectioned longitudinally through the center of the restorations with the help of Isomet diamond saw under water coolant. The sections were then observed under a binocular stereomicroscope at a magnification of 20X. The depth of dye penetration at tooth-restoration interface was blindly scored by two independent investigators. Results: Microleakage seen in increasing order at the enamel-restoration junction is Alkasite material-Cention N followed by Tetric-N-Flow and Gaenial universal Flo. Microleakage seen in increasing order at dentin-restoration junction is Tetric-N-Flow then Cention N and Gaenial Universal flo Conclusion: Microleakage at enamel-restoration interface was less than microleakage at dentin-restoration interface of each group, but the difference was not statistically significant. Least microleakage at the enamel-restoration junction was seen with Cention-N with Adhesive followed by the flowable composite and least microleakage at dentin-restoration interface was seen with flowable composite followed by Cention N with adhesive. More microleakage was seen with Gaenial universal Flo at both enamel/dentin –restorative interface.