Aims and Objectives: Viability and health of the pulpal tissue after an exposure can be stimulated with biocompatible pulp capping materials. Mineral trioxide aggregate(MTA), though biocompatible with excellent sealing ability, has clinical disadvantages like poor handling properties and long setting time. New pulp capping agents- Biodentine and Theracal have proven to overcome MTA's shortcomings. This study aimed to comparatively evaluate the sealing ability of Mineral Trioxide Aggregate(Angelus), Biodentine (Septodont) and Theracal(Bisco) when used as pulp capping agents. Materials and Methods: Occlusal cavities were prepared in extracted human third molars. The cavities were divided into 3 groups containing 12 samples each. Pulp capping in samples of group I, II and III was done with MTA, Biodentine and Theracal respectively. All samples were kept in a damp environment for 24 hrs. In each tooth, the root was cut just below the cementum-enamel junction. An aqueous 0.25% solution of Rhodamine-B was put in the open pulp chambers of all the samples and placed upside-down in a damp environment. The dye was left for 3 hrs to permeate toward the interface. After being stained, all samples were rinsed with distilled water and sectioned vertically. A Confocal Laser Scanning Microscope was used to image the samples. Results: No significant difference was found in interfacial microleakage between MTA and Biodentine. Theracal exhibited less interfacial microleakage than the two. Conclusion: Biodentine and MTA exhibit an efficient and durable protection of pulp. Theracal exhibits better sealing ability as a pulp capping agent than MTA and Biodentine.