In which cases is it necessary to renew the root canal treatment?

Re-root canal treatment is necessary when the initial treatment fails; these conditions include persistent infection, missed root canals, inadequate cleaning, or faulty restorations. Studies show that recovery rates for re-root canal treatment range from 78% to 87%, and success depends on factors such as the absence of pre-existing lesions and the correct root filling length. The success rate at 5 years is approximately 89%.