CBCT Reveals Root Resorption Unseen in Regular Radiography

The following case shows the advantage of CBCT in endodontic diagnosis.


The following patient returned to our office today for re-evaluation of #14. We previously looked at #14 which had some gingival swelling, yet we could not definitively diagnose the tooth as necrotic. We assumed the swelling was a periodontal abscess and had given him an antibiotic. He returned reporting no relief with the antibiotic and short, spontaneous episodes of severe pain. Once again our diagnostics were inconclusive. Normal to palpation, normal to percussion, normal to probing, responsive to cold on the lingual and unresponsive on the buccal, normal response to EPT. The canals were obviously calcified and the pdl looked normal around the roots. We decided we would take a CBCT to see if we could see any additional radiographic changes.

The CBCT clearly shows a resorptive defect on the palatal. The CBCT also tells us the location (mesio-palatal), the size of the defect which allows us to make a restorative call.

Look again at the initial film. There is no sign of this resorption with traditional 2D imaging. CBCT continues to surprise me.

The Importance of Quality Initial Root Canal Therapy

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.

SOURCES:

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.