It is fair to say that endodontic retreatment has a lower success rate than initial endodontic therapy. This highlights the importance of good INITIAL endodontic therapy.
In a study by Boucher et. al. (2002) to evaluate the quality of endodontic treatment in a French subpopulation of 204 patients, looking at approximately 2,010 obturated canals, found that canals were filled to an acceptable standard 21% of the time.
Chueh et. al. (2003) in a similar study in Taiwan to evaluate root canal filling for length and fill density in 1085 RCT cases found similar results. Their study found that RCT fill and/or length was inadequate 70% of the time.
Gumru et. al. (2011) in a similar study, using a Turkish subpopulation, looked at 459 root filled teeth and found the technical quality inadquate 60.1% of the time.
After looking at the data reproduced by these studies, it would be reasonable to say that the number of endodontic retreatment cases could be reduced by improving the quality of initial endodontic therapy. If we know that initial endodontic therapy has higher success rates than endodontic retreatment, it is our duty to make good treatment decisions and give our patients the best chance for successful initial endodontic therapy. This may mean referral to a specialist on more difficult cases such as molars, RCT through crowns/bridges or cases with calcified canals. Deciding when to refer to an endodontist can be a difficult decision. The AAE has published a case difficulty assessment form to help dental professionals with that decision making process.
With all that being said, there has been a lot of misinformation regarding endodontic retreatment. While success rates for retreatment are lower than initial endodontic therapy, at Superstition Spring Endodontics, we have excellent success with retreatment. The case below demonstrates that when retreatment is able to correct the issue causing initial failure, success is achievable.
To find out an accurate success rate of endodontic retreatment, click here or come to our upcoming Inner Space Seminar.
Boucher et. al. "Radiographic evaluation of the prevalence and technical quality of root canal treatment in a French subpopulation". Inter Endod Journ 2002; 35:229-238.
Chueh, L.H. et. al. "Technical quality of root canal treatment in Taiwan". Inter Endod Journ 2003; 36:416-422.
Gumru et. al. "Retrospective radiological assessment of root canal treatment in young permanent dentition in a Turkish subpopulation". 2011;44:850-856.