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Endodontics · single question

A mature maxillary central incisor with a closed apex is intruded following trauma. What is the most likely pulpal outcome?

  1. Reversible pulpitis resolving within two weeks
  2. Pulp necrosis in the great majority of cases, requiring root canal treatment
  3. Spontaneous pulpal healing in most cases
  4. Pulp canal obliteration without necrosis
Show answer and explanation

Correct answer: B. Pulp necrosis in the great majority of cases, requiring root canal treatment

  • A. This injury does not resolve as a reversible pulpitis — the blood supply has been severed.
  • B. CORRECT. In a CLOSED-APEX tooth the apical foramen is narrow and there is no capacity for revascularisation once the neurovascular bundle is severed. Reported rates of pulp necrosis after intrusion of mature teeth approach or exceed 90%. Endodontic treatment should be initiated PROPHYLACTICALLY, typically within 2–3 weeks of repositioning, to pre-empt inflammatory external resorption.
  • C. Spontaneous healing is characteristic of IMMATURE teeth with wide open apices, which can revascularise.
  • D. Pulp canal obliteration is a healing response seen mainly after less severe luxations in immature teeth, not the expected outcome of mature intrusion.

Note: Open apex intruded up to about 7 mm: allow spontaneous re-eruption and monitor. Closed apex: reposition (orthodontically or surgically) and start root canal treatment prophylactically.

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