Fifteen-year Survival of Root Canal Treated Posterior Teeth.

Objectives: To measure the fifteen year survival curve for root filled posterior teeth in adult patients treated within the General Dental Services in England and Wales (GDS).
Methods: The data source was adult GDS patients and the treatments they received from 1/10/1990 to 31/3/2006.

Re-intervention was either re-root canal treatment, apicectomy or extraction after root canal treatment. Analysis by modified Kaplan-Meier methodology was utilized to establish survival curves extending to fifteen years.

The period of 4 year follow up in line with European Society of Endodontology (ESE) guidelines were noted.

Associations between the survival curve and tooth notation and presence of a cuspal coverage restoration as a crown were also investigated.
Results: The full database contains over 25 million courses of treatments on 2.7 million adult patients and 894,036 teeth were root canal treated.
The 4 year follow up showed that 93.5% and at 15 years, 86% of root canal treated teeth had not received re-intervention. After 15 years there was variation in survival by tooth position.
Root canal treated teeth with a crown survived 96% at 4 years compared to 93% for those without and at 15 years 88% versus 85%.
In the first year 24,969 teeth required re-intervention., 68% were extracted, 30% re-root canal treated and 2% apicected. At 10 years figures were: 85%, 15% and less than 1%.
Conclusions: It was found that the 86% of teeth that had been root treated survived for 15 years without requiring re-root canal treatment, apicectomy or extraction.
The teeth that had the best prognosis were lower premolars and lower third molars at 88%.
The posterior teeth that had been crowned survived better than without a crown by around 3 percentage points.