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Endodontics Flashcards

7 cards from real NBDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Endodontics flashcards as text

  1. Which radiographic finding is most characteristic of a periapical abscess compared to a periapical granuloma?

    Answer: Diffuse radiolucency with poorly defined margins

    Periapical abscesses typically appear as diffuse, poorly defined radiolucencies due to rapid bone destruction, whereas granulomas have more defined borders.

  2. A patient presents with a tooth that tests vital with cold but has a periapical radiolucency. What is the most likely diagnosis?

    Answer: Non-odontogenic lesion or anatomical landmark

    A vital pulp response with a periapical radiolucency suggests a non-odontogenic etiology or an anatomical structure (e.g., mental foramen, incisive canal) rather than pulpal pathology.

  3. During root canal preparation, the working length shortens by 2mm unexpectedly. What is the most likely cause?

    Answer: Ledge formation

    Ledge formation creates a false canal wall that blocks instrument passage to the apex, causing an apparent reduction in working length.

  4. Which irrigant is most effective at dissolving organic pulp tissue remnants during root canal treatment?

    Answer: Sodium hypochlorite (5.25%)

    Sodium hypochlorite is the only endodontic irrigant with proven ability to dissolve organic tissue due to its proteolytic action.

  5. What is the primary purpose of the smear layer removal step using EDTA in root canal treatment?

    Answer: Open dentinal tubules to improve sealer penetration

    EDTA chelates calcium ions and removes the inorganic smear layer, exposing dentinal tubule openings to allow deeper sealer penetration.

  6. A tooth with a symptomatic irreversible pulpitis most commonly presents with which combination of symptoms?

    Answer: Spontaneous pain and lingering pain to thermal stimuli

    Symptomatic irreversible pulpitis is characterized by spontaneous pain and prolonged, lingering response to thermal stimuli lasting more than 30 seconds.

  7. Which rotary file system design feature reduces the risk of instrument separation?

    Answer: Asymmetric cross-section with off-center design

    Asymmetric (off-center) cross-sections reduce the contact area with dentin walls, lowering torsional stress and the risk of fracture.