
One of the keys to successful root canal therapy is adequate obturation of the prepared root canal space. Three dimensional obturation provides hermetic seal to prevent ingress of bacteria and their toxins into the periapical tissues and when this is not achieved by an orthograde approach, then a root end filling technique is used. The purpose of a root-end filling is to establish a seal between the root canal space and the periapical tissues. A number of materials have been suggested for use as root-end fillings, including gutta-percha, amalgam, Cavit, intermediate restorative material (IRM), super EBA, glass ionomers, composite resins, carboxylate cements, zinc phosphate cements, zinc oxide-eugenol cements and mineral trioxide aggregate (MTA). This article reviews different root end filling materials and compare their biocompatibility, sealing ability and microleakage.