Mechanical preparation of root canals: shaping goals, techniques and means

Preparation of root canal systems includes both enlargement and shaping of the complex endodontic space together with its disinfection. A variety of instruments and techniques have been developed and described for this critical stage of root canal treatment. Although many reports on root canal preparation can be found in the literature, definitive scientific evidence on the quality and clinical appropriateness of different instruments and techniques remains elusive. To a large extent this is because of methodological problems, making comparisons among different investigations difficult if not impossible. The first section of this paper discusses the main problems with the methodology of research relating to root canal preparation while the remaining section critically reviews current endodontic instruments and shaping techniques.