The process of tissue repair is essential to re-establish function and tissue integrity. The ideal goal of endodontic treatment is to achieve periapical healing. Whenever there is an infection or injury, host evoke a protective response by immunoinflammatory process to maintain the original structure and biological function of the tissue. Periapical diseases are mostly due to disintegrated products of pulp tissue or due to toxins produced by the bacteria in root canal system. More than 90% of periapical lesion are dental granuloma, radicular cysts or abscesses. As non- surgical endodontic...