The aim of endodontic treatment is to remove all infected hard or soft tissue and to restore the tooth with a bacteria-tight restoration in order to preserve the health of the tooth and its supporting tissues. Inflammation is the local physiologic reaction of the body to noxious stimuli or irritants. Any irritant, whether of traumatic, chemical or bacterial origin, produces a sequence of basic physiologic and morphologic reactions in vascular, lymphatic and connective tissues. The changes that occur are mediated by a series of inflammatory and immunological reaction. All these reactions take place to eliminate the irritant and repair damage.