As stated above, a root canal treatment may become necessary when the inner root of a tooth or several teeth becomes infected, resulting in moderate to severe pain and discomfort. While many patients may not like the idea of having a root canal done, the effects of leaving an infected tooth untreated can be profound. In some cases, an abscess can form, resulting in even more discomfort. A root canal procedure removes the infected material from within the teeth and protects the tooth from further infection.