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Endodontics · single question

An FMX shows multiple teeth with root canals. One tooth has an incomplete root canal fill (short of apex) with minimal periapical pathology. Which tooth needs retreatment?

  1. The tooth with a well-adapted crown but no pathology
  2. The tooth with incomplete fill (short of apex) and minimal periapical pathology
  3. The tooth with perfect fill and no pathology
  4. The tooth with an overfilled canal
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Correct answer: B. The tooth with incomplete fill (short of apex) and minimal periapical pathology

A root canal filling that is short of the apex + minimal periapical pathology = failed endodontic treatment. The short fill leaves the apical portion untreated, allowing bacterial recolonization. Any periapical pathology associated with a short fill indicates retreatment is needed. Source confirms highlighted tooth: 'root canal wasn't complete 4 and had a minimal pathology.'
  • A. Well-adapted crown with no pathology = successful treatment — no retreatment needed.
  • B. CORRECT. Short fill (not to apex) + minimal periapical pathology = inadequate apical seal → failed RCT → retreatment indicated.
  • C. Complete fill with no pathology = successful treatment — no retreatment needed.
  • D. Overfilled canals may cause periapical irritation but the sealing may still be adequate — not specifically indicated for retreatment.

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