Root canal therapy may be required to resolve problems relating to nerves and tissue, or 'pulp' within the core of the tooth root. Often decay or infection may exist in the root which, if left un-treated, will require complete removal of the tooth.
Typically pulp within the root can become diseased or injured by a cavity the extends deep within the tooth, or through some sort of breach such as a cracked tooth.
A restored tooth can easily last a lifetime, and is a highly successful solution with diligent care of teeth and gums.