What happens during root canal therapy?

Removes tooth nerve. The goal of root canal therapy is to clean out the infected nerve and blood vessels inside the tooth. Removing that tissue will control the infection. Dentists use very fine instruments to clean out the tissue, and then place a material inside the tooth to provide strength and prevent other bacteria from getting inside.
A few steps. The dentist uses a handpiece to open up the top of the tooth to get to the pulp chamber. They then remove the dead or infected pulp, clean out the canals and put a filling material in the canal. This can take 1 or 2 appointments.
Root Canal. As the other 2 Drs. have clearly explained what goes on during, what happens after is equally important, restoration of the tooth. All too often I extract teeth that had successful RCT and then the patient disappears and fails to get the tooth restored properly . The tooth can become decayed, or fracture , if not properly restored, and sadly need extraction.