Presentation Blocks: 03-22-2018 - Thursday - 11:00 AM - 12:15 PM

Title: Multi-state Outcome Analysis of Treatments for Teeth Treated With Non-surgical Root Canal Therapy (NS-RCT)


Alex Moore (Presenter)
Marquette University

Sheila Stover, Marquette University
Frederick Eichmiller, Delta Dental of Wisconsin
Lisa Rein, Medical College of Wisconsin
Pradeep Bhagavatula, Marquette University
Aniko Szabo, Medical College of Wisconsin


Objectives: To compare the transitions between failure states (no failure, non-surgical retreatment, surgical retreatment, extraction) for teeth undergoing non-surgical root canal therapy (NS-RCT) based on initial provider type.

Methods: Insurance claims were analyzed for 438,487 initial NS-RCT procedures to determine the effect of initial provider type (endodontist vs. non-endodontist) on subsequent interventions. The initial NS-RCT and re-intervention procedures (non-surgical retreatment, surgical retreatment, and extraction) were identified using Code on Dental Procedures and Nomenclature (CDT) codes. A multi-state model with six transitions was created using the ‘mstate’ R package (only transitions to a higher level of re-intervention were allowed). The cumulative hazard and transition probabilities from the model were plotted for all NS-RCT procedures and separately by initial provider type.

Results: Most teeth that were treated by NS-RCT had no subsequent treatment interventions at the end of the 10-year follow-up period. Teeth that were retreated surgically or non-surgically were more likely to be extracted than teeth that did not have such an intervention. Teeth were more likely to be extracted than retreated. Teeth were more likely to be retreated non-surgically than surgically. If a tooth had a non-surgical retreatment and then subsequently had a surgical retreatment, then it was more likely that the surgical intervention occurred during the first year of treatment. A tooth that was treated by a non-endodontist was more likely to undergo non-surgical retreatment or extraction than if the initial therapy was provided by an endodontist.

Conclusions: The results demonstrate that NS-RCT failures are most likely to result in tooth extraction. When retreatment is performed, it is more likely to be non-surgical and retreatment in any form increases the likelihood for future extraction. NS-RCTs initially performed by non-endodontists also have a greater chance for non-surgical retreatment or extraction as a final outcome.