Method:
Cases were selected from the patient pool at the Sydney Dental Hospital and other associated health services. Selection criteria were based on teeth that had undergone root canal therapy and subsequently extracted within one year after completion. Associations between tooth extracted, age, gender, smoking status, coronal restoration and the reason for failure were collected from patient files and explored.
Results:
The most commonly extracted tooth due to endodontic failure was the 2nd maxillary premolar and the temporary filling material with the highest failure rate was glass ionomer cement. This study identified the highest failure rate was that of prosthetic modality (unrestorability) with 44.12% of endodontically treated teeth being extracted. More specifically, crown or root fracture, rather than failure of the endodontics was the most likely reason for the extraction of endodontically treated teeth within 12 months of obturation.
Conclusions:
The success rate of root canal treatment on 4318 teeth within the Sydney South West Oral Health Service between 2008-2013, was 98.4% within one year of completion. This study found that the majority of failures of endodontically treated teeth were due to un-restorability because of extensive tooth destruction, such as, root and crown fracture. Clinically, this data supports the need for clinicians to place definitive restorations as soon as possible after root canal treatment to increase the likelihood of tooth survival.