# Root‐Filled Teeth With and Without Pain in a Cohort of Individuals Scheduled for Regular Dental Check‐Ups. A Matched Case–Control Study

## TL;DR

This study compares painful and pain-free root-filled teeth to identify factors that may explain the presence of pain.

## Contribution

The study provides insights into the clinical and radiographic features associated with pain in root-filled teeth.

## Key findings

- Tenderness to percussion and apical palpation were more common in painful teeth.
- Apical radiolucency and deeper probing depths were associated with pain in root-filled teeth.
- For 10% of the symptomatic teeth, no clear cause of pain could be identified.

## Abstract

An overwhelming majority of root‐filled teeth are asymptomatic, despite commonly exhibiting radiological signs of apical periodontitis (AP). When symptoms prevail, several sources are conceivable. This case–control study investigates underlying causes of pain from root‐filled teeth.

The aims were to (i) compare painful root‐filled teeth with root‐filled teeth without pain matched on sex, age, jaw and tooth type, and (ii) explore patient‐ and tooth‐related factors that may explain the pain.

Adult participants (≥ 20 years) with root‐filled teeth were investigated through anamnestic, clinical and radiographic examinations. Analyses compared painful to pain‐free teeth statistically, and possible origins of pain were indicated. Clinical data and periapical radiographs were used to identify the presence of AP.

Tenderness to percussion and apical palpation, probing depth ≥ 6 mm, swelling and apical radiolucency (p = 0.002–0.040) were more common with painful teeth, while density and length of root filling, unfilled canals, fracture of root and positive screening for TMD (3Q/TMD) did not differ between groups (p = 0.074–0.63). Among the 55 symptomatic teeth, AP was identified in 48 with varying diagnostic certainty. Indication of temporomandibular disorder (TMD) was present in 15 teeth, and marginal periodontitis (MP) in eight teeth. For six teeth, none of the three conditions could be identified.

Tenderness to percussion and apical palpation, swelling, pocket depth ≥ 6 mm, and apical radiolucency were more common with painful teeth. The pain was most frequently associated with AP, but pain due to TMD and MP may occur. For 10% of the root‐filled teeth, no findings could explain the symptoms.