E. faecalis in Retreatment — NDEB AFK MCQ
Instant feedback + full explanation. One question, done properly.
Educational content. Not a substitute for clinical judgement or local policy.
Reveal the answer and explanation
Correct answer: C — Enterococcus faecalis
Enterococcus faecalis is the organism most frequently isolated from root canals of teeth with failed endodontic treatment (retreatment cases). It is a Gram-positive, facultative anaerobic coccus that is resistant to calcium hydroxide (tolerates alkaline pH up to 11.5), can survive in nutrient-poor environments, and penetrates deeply into dentinal tubules. It can also form biofilm. Its resistance to intracanal medicaments and irrigants contributes to persistent periapical infection. This is why aggressive disinfection protocols are especially important during retreatment.
Reference: Torabinejad – Endodontics: Principles and Practice, 6th ed., 2021