In rare cases, root canal therapy fails to work as expected. When this occurs, repeating of the process can usually achieve a successful result, providing that the canals can be easily re-accessed. In some cases, for example, the presence of posts or other restorative materials might complicate attempts at retreatment. In other cases, removal of the previous root canal fillings and cements may be a problem. As long as any blockages can be dealt with, however, the process then becomes almost identical to the original procedure. The success rate for a root canal retreatment can be expected to be around 75%- 80%.
Root canal treatments and retreatments are a better alternative than extraction for most patients. If a tooth has adequate structure and good bone support, most endodontic issues can be resolved. Understand that implants are not a sure thing, and there is nothing better for your oral health than your own natural tooth.