Preparing the master cone to fit the shape of the canal vs. preparing the canal to the shape of an industrial master cone

Customized master cones represent a change in concept: rather than instrumenting the root canal to fit the shape of a round, industrial, master cone, a cone is prepared to fit the shape of the ready-to-fill canal. As such, it may be effectively used in round canals of any size and taper, in oval canals or in those with an irregular shape, regardless of which file system was used to shape the canal. In many dental schools, this method has been avoided and not been taught due to a long-outdated ban on the use of chloroform in endodontics. The aim of this paper is to highlight the benefits of customized master cones and to explain in detail a method of their preparation, so every dentist or endodontist can apply it, including those who have never had the opportunity to master this useful procedure during their endodontic studies.