Pain after root canal treatment: a missed canal or something else?｜證據鏈

Short-term sensitivity to pressure or biting after root canal treatment is a different situation from recurrent pain that remains months later. The latter may involve a missed canal, coronal leakage, persistent periapical inflammation, a cracked tooth or occlusal loading; it may also originate from an adjacent tooth, the temporomandibular joint, the masticatory muscles or nerve-related pain. Only after locating the source of the pain can we know whether retreatment would address its cause. In a multicentre prospective cohort, 65 of the 651 participants who completed six-month follow-up (10.0%) met the definition of persistent pain. Another in-depth assessment of people still in pain at six months covered the 19 (50%) of 38 people meeting the pain criteria who consented to be examined: 7 (37%) had an odontogenic cause, 8 (42%) a non-odontogenic cause, 2 (11%) both types of cause, and a further 2 (11%) no longer met the pain criteria at the time of the clinical evaluation. The denominator is very small and self-selected (only those who consented entered the analysis), so it cannot be treated as the proportion seen in general practice. What it genuinely highlights is that immediately repeating root canal treatment when symptoms persist may mean treating the wrong target.