With the appropriate care, your teeth that have had previous root canals can last as long as your other natural teeth. Yet, a tooth that has received treatment may fail to heal or pain may continue to exist. At times the pain may occur months or years after the initial treatment. If so, retreatment of the previous root canal may be indicated. This would entail removing the previous root canal material, cleaning out the roots and refilling the roots. Again it is essential to follow up with your general dentist in a timely manner. They will provide a permanent restoration and seal for the retreated root canal.