
Root canals are dental procedures used to treat and preserve teeth with badly infected roots. The pulp is the live portion of the tooth containing nerve and blood vessels. When it becomes infected due to decays and bacteria, patients can experience pain, swelling which if left untreated, patient may lose the tooth.
Root canals process removes the damaged parts of the infected tissues inside the tooth and seal it from further bacteria invasion. An antibiotic is also usually prescribed to help prevent further infection after the root canal procedure. The remaining portion of the tooth may be restored using a cap or crown that provides a natural appearance and normal tooth function.
http://www.mouthhealthy.org/en/az-topics/r/root-canals