An opening is made in the crown of the tooth. This allows access to the root canal system. It is very important to have a large enough opening to find all the canals inside a tooth. Anatomy inside the tooth is variable. Some teeth have just one canal like most upper front teeth. Premolars usually have 1 or 2. Molars or the back teeth typically have 3 or 4. Especially in back teeth, a surgical operating microscope with great illumination allows visualization much better to help find these canals.
The pulp is removed from the pulp chamber and root canals. Tiny instruments are used to clean the root canals and to shape them to a form that will be easy to fill. Irrigants are used to dissolve and flush out debris. If this step is not completed in one visit, medication will be placed in the canals and a temporary filling will be placed in the opening to protect the tooth between visits. Radiographs (X-rays) are taken periodically during the cleaning process to check if the instruments are cleaning near the end of the root.