The utilization of an elastic dam for tooth isolation is mandatory in endodontic treatment for several reasons: It gives an aseptic operating field, isolating the tooth from oral and salivary contamination. Root canal contamination with saliva introduces new microorganisms to the root canal which compromise the prognosis. It facilitates the utilization of the strong medicaments necessary to clean the root canal framework. It shields the patient from the inhalation or ingestion of endodontic instruments.
There have been various dynamic iterations to the mechanical preparation of the root canal for endodontic therapy. The first, alluded to as the standardized system, was created by Ingle in 1961, and had disadvantages, for example, the potential for loss of working length and inadvertent ledging, zipping or perforation. Ensuing refinements have been various, and are usually depicted as methods. These include the step-back, circumferential filing, incremental, anticurvature filing, step-down, twofold flare, crown-down-pressureless, balanced force, canal master, apical box, dynamic enlargement, changed twofold flare, passive stepback, alternated rotary motions, and apical patency techniques.
This procedure, be that as it may, has a few disadvantages, for example, the potential for inadvertent apical transportation. Incorrect instrumentation length can happen, which can be addressed by the altered step back. Obstructing debris can be dealt with by the passive step back procedure. The crown down is a procedure where the dentist prepares the canal beginning from the coronal part after exploring the patency of the entire canal with the master apical record.