A root canal treatment is suggested when the tooth is badly decayed or infected. It is caused by the bacteria that live in the mouth and eventually invade the tooth. To treat this infection, we remove the bacteria by removing the pulp from the root canal and then filling the root canal and sealing it. The best way to avoid root canals is to take good daily care of your teeth to prevent the growth and spread of bacteria. Brushing and flossing are important.