Endodontic nonsurgical retreatment is a comprehensive field. This field of endodontic has its own science, literature, specific technologies, best materials, and escalating range of techniques that are, at times, required to achieve clinical success. It may be divided into the following categories: coronal disassembly, locating previously missed canals, removing obturation materials, negotiating blocks, bypassing ledges, managing transportations, repairing perforations, treatment planning fractures, and removing posts and broken instruments. However, not all failures are amenable to...