Dental professionals face difficulty in managing "immature non-vital teeth with an open apex." It is considered to be challenging because, in this situation, root canal filling material should be confined within the boundaries of the root canal without extruding peri-apically. Apexification tries to create a hard tissue barrier that will cause the open apex to close, allowing root filling to be compacted. The current case report describes the application of mineral trioxide aggregate (MTA) to create an apical plug in an open apex, as MTA is considered a versatile material for apexification, which was followed by the reinforcing of the weekend root using glass fiber post and core build-up to manage the Ellis class IV fracture.