Validation of the effectiveness of the Dental Practicality Index in predicting the outcome of root canal retreatments.

AIM

To assess the effectiveness of the Dental Practicality Index (DPI) in predicting the outcome of root canal retreatment in posterior teeth.

METHODOLOGY

One hundred and thirty-seven posterior teeth with symptoms and/or signs of post-treatment endodontic disease requiring root canal retreatment and previously included in a clinical trial were selected. Clinical and radiographic examinations including digital periapical and cone beam computed tomography (CBCT) were obtained pre-treatment and 1-year postoperatively from a previous study. Two calibrated and trained assessors who were unaware of the treatment outcome assessed the pre-treatment clinical records of these cases using the DPI. The DPI score was then compared to the outcome of the root canal retreatment. A Chi-square/Fisher's exact test was used to establish a relationship between categorical variables, the total score of DPI vs outcome.

RESULTS

Retreated teeth with DPI scores equal to 6 or above had an unfavourable outcome of 50% vs 14% of teeth with DPI below 6. Teeth with DPI score equal to 3 or above had an unfavourable outcome of 23% versus 2%, for teeth below 3. Molar teeth with a DPI score below 3 had a favourable outcome percentage of 96%.

CONCLUSIONS

This study highlighted that using the DPI gave a good outcome prediction for root canal retreatments. However, further research, including the prospective assessment of a wider range of cases undertaken by a larger group of examiners is needed to further validate the DPI.