The purpose of an RCT is to clear the pulp cavity of neurotic tissue and then create a complete seal that will prevent bacteria from entering and exiting the RC . An RCT may be necessary due to gross caries reaching the RC or leakage from a previous RCT or trauma which will cause loss of vitality resulting in interruption of blood and/or nerve supply. The ECR can be divided into the following stages: 1. Preoperative X-rayA preoperative X-ray provides the dentist with information about the RC filling and its subsequent analysis. The dentist is able to see how far the RCT blockage extends, allows him to identify the RCT orifice and get an idea on how to negotiate the root canals15. An example of RCT blockage is the appearance of calcification in the RCT. Only in rare cases are blockages not identifiable. This location and region of blockage of the RC allows the dentist to choose the most effective method of removing anything blocking the RC so that ECR can begin, for example in order to be able to treat a RC in a maxillary premolar, the access for coronal penetration. begins at the center of the occlusal surface and following the long axis of the tooth. The RC port is identified with an explorer when pressed where, based on the x-ray, the port is believed to be. If there is indeed an orifice present, the explorer will dislodge slightly by pressing on the blocked orifice. To minimize perforation and reconfirm the port location, a second radiograph is taken with the explorer left in place15.2. Coronal preparation/accessBefore RC access begins, the dentist places a TB dam – a thin sheet of latex – with a hole on the tooth to be treated after...... middle of paper ..... .nts new microorganism to enter the RC. Then, a finger retractor (fine (F) when the master file used was <25 and a less fine retractor (MF for master file size 30+) is placed in the RC with downward pressure and removed by rotating and turning the spreader towards the This allows the sealant to spread laterally towards the walls of the RC This whole process is repeated so far with more adjustment of the GP point and the whole canal is pink in color (. pink color of the GP point, this suggests) that there are still spaces left and carried, microorganisms or RC could leak. Finally, a hot excubator is used to cut the ends of the GP points that protrude from the RC. But in order to completely seal the RC, a restoration is placed on the treated RC. This will completely detach the RC from the external environment and prevent wear and abrasion of the RC..