When the nerve of your tooth becomes infected, a root canal treatment is the treatment that allows you to keep your tooth. The dentist removes the infected, injured or dead pulp from your tooth. The dentist enlarges the root canal system and cleans it. Then the canal is sealed with a special material, and the opening of the tooth is then sealed with a temporary or a permanent filling. A root canal treatment does not protect your teeth from other types of damage, such as decay or gum diseases.