A file separates in the APICAL THIRD during root canal therapy. Which initial pulpal/periapical diagnosis carries the BEST prognosis?

Correct answer: D. Vital pulp with no periapical lesion

• A. A non-vital pulp means the canal system is already infected, so failure to disinfect apical to the fragment compromises the result.
• B. A periapical lesion signals established infection; leaving apical tissue uninstrumented behind a fragment worsens the outcome.
• C. This is the WORST scenario — a necrotic, infected canal with established apical periodontitis, where the fragment obstructs the very region requiring disinfection.
• D. Correct. A separated instrument matters chiefly because it blocks disinfection of the canal apical to it. If the pulp was VITAL and there was NO periapical pathosis, the canal was not significantly infected, so the un-instrumented apical portion harbors little bacterial load and the prognosis is essentially unaffected. Current guidance is NOT to attempt retrieval of an apical-third fragment in this situation.

Note: Document the incident, inform the patient, and follow up radiographically. Retrieval attempts in the apical third risk perforation, ledging and root weakening.