Prevalence of apical periodontitis in root-canal-filled teeth - a cross-sectional study.

Researchers found that nearly one-third of root-canal-filled teeth in a Swedish population showed signs of apical periodontitis, with inadequate root canal filling quality being common—particularly in molars, where 47% displayed apical pathology.

A plain-English summary of the study's own findings — we don't add our own claims or interpretation. Read the full paper for the complete methods and results, and apply your own clinical judgement.