Endodontics is a field of dentistry which deals with the morphology, physiology and pathology of the pulp and periradicular tissue. Endodontic treatment involves a series of steps which must be carried out according to the rules of the profession in order for the outcome of the treatment to be successful: diagnosis, anesthesia, isolation, trepanation opening, instrumentation of the root canals and filling. An important part of endodontic endodontic treatment is isolation, i.e. achieving a dry field by applying a rubber dam. If we want to achieve a dry field, an important step is tooth reconstruction. Pre-endodontic reconstruction is also vital since most teeth, for which endodontic treatment is indicated, have a significant loss of hard dental tissues. The procedure includes both an assessment of the restorative status of the tooth (structural, periodontal, endodontic) as also considering local and general factors. After removal of previous restorations, tooth decay and unsupported soft tissue, we must assess the possibility of tooth restoration. Conservative techniques are cervical margin relocation, donut technique, canal projection and open sandwich technique. Surgical techniques are surgical crown lengthening, surgical extrusion and orthodontic extrusion.