When the pulp inside the tooth becomes infected, you might experience severe tooth pain that doesn’t really go away. Tooth pain can get worse when you start eating or when you drink cold or hot drinks. These are some of the warning signs of an infection in the mouth and must be treated immediately with a root canal. Contrary to popular belief, a root canal isn’t a very complicated procedure, nor is it extremely painful. In fact, the most pain you feel is probably the tooth pain you suffered through before you underwent treatment.