Pediatric endodontics is an integral part of dental practice that aims to preserve fully functional primary teeth in the dental arch. Despite advances in the prevention of dental caries in pediatric dentistry, the occurrence of pulpally involved primary (deciduous) teeth and their premature loss continues to be a common problem.Pulpectomy of primary molars presents a unique challenge for dental practitioners. Complete debridement, chemical and mechanical preparation, and a three-dimensional seal are all necessary for root canal therapy to be successful. There are different file systems and techniques of instrumentation. This book puts special emphasis on SEM/ ultramicroscopic structure of root canals prepared using rotary instrumentation.