According to the American Association of Endodontists, more than 15 million root canals are performed in America each year. You may not have looked forward to undergoing root canal therapy but having to repeat the procedure is even less desirable. As with any medical treatment, root canals are not 100% effective and several factors may lead to the reinfection of your tooth. In this post, your dentist explains the symptoms of a failed root canal and how to prevent complications in the first place.