Root cannal. Same tooth being infected.

In root canal treatment the nerves are removed is the very basic understanding. Root canal is a a complex 3 dimensional space filled with living tissue called pulp which of course containg nerves. The root canal system is the apt name to be used. When decay or infection reaches the pulp the entire system is infected with bacteria. In the Root canal  treatment the entire system needs to be disinfected and filled. The 100 percent of which cannot happen due to in accesibilty and anatomic complexities of the canal system. Re infection can occur due to various reasons. Resistant e. Coli or e. Fecalis infection of the system. Anatomic complexities of the canals. Lateral canals. Leakage through the filling material. Or coranal leakage. Recurrent decay on the same tooth. Micro cracks in the tooth or roots. And many more. Nevertheless the root canal treatment is a way to save the tooth which is already infected. Re root canal treatment is possible and may help. I hope that the question is answered in a way you have understood. If not happy to help. Warm regards