The completion of root development and closure of the apex occurs up to 3 years after the eruption of the tooth. treatment of choice for necrotic teeth with immature root is apexification, which is induction of apical closure to produce more favorable conditions for conventional root canal filling. The most commonly advocated medicament is calcium hydroxide. However, this material requires a long time to form the hard tissue barrier. It has also been shown that the use of calcium hydroxide weakens the resistance of the dentin to fracture. Recently considerable interest has been expressed in the use of mineral trioxide aggregate (MTA). The most important properties of these material in dentistry are its biocompatibility and sealing ability. High biocompatibility encourages optimal healing responses. This has been observed histologically with the formation of new cementum in peri radicular tissues area and a low inflammatory response with bridge formation in the pulp space. Moreover, MTA offers the option of a two visit apexification procedure so that the fragile tooth can be restored immediately.