Gutta-percha and sealer alone used routinely as root canal obturating material are found to be ineffective to guard against microleakage. Even clinically acceptable root filling allow penetration of bacteria and their products in as less as three days and contribute to eventual treatment failure. This breach of seal in coronal segment of obturated root canal may significantly jeopardize endodontic treatment outcome particularly in molars because of presence of accessory canals in the floor of the pulp chamber.