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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 obturation technique involves heating gutta-percha and compacting it into the canal using a carrier?

    Answer: Carrier-based obturation (Thermafil)

    Carrier-based systems like Thermafil use a plastic or metal carrier coated with alpha-phase gutta-percha that is heated and inserted to fill the canal.

  2. A patient develops paresthesia of the lower lip after root canal treatment of a mandibular second molar. What is the most likely cause?

    Answer: Over-instrumentation beyond the apex compressing the inferior alveolar nerve

    Overfilling or aggressive instrumentation beyond the apex of mandibular molars can impinge on or chemically injure the inferior alveolar nerve, causing paresthesia.

  3. What distinguishes a Type IV canal configuration (Weine classification) from Type III?

    Answer: One canal that divides into two at the apex with two foramina

    Weine Type IV begins as one canal and divides near the apex into two separate canals with two distinct apical foramina.

  4. Which condition is an absolute contraindication to performing a pulpotomy on a primary molar?

    Answer: Pathologic internal root resorption

    Pathologic internal root resorption indicates the radicular pulp is irreversibly inflamed and infected, making pulpotomy (which preserves the radicular pulp) contraindicated.

  5. The zone of coagulation necrosis seen after MTA or calcium hydroxide apexification therapy heals primarily by which process?

    Answer: Cementum deposition over the apex (cementogenesis)

    Calcium hydroxide and MTA promote apical closure primarily through cementogenesis, with cementum-like hard tissue deposited over the open apex.

  6. A mandibular first molar shows a 'J-shaped' periapical radiolucency extending along the lateral root surface. What is the most likely cause?

    Answer: Vertical root fracture

    A J-shaped radiolucency along the lateral root surface extending to the apex is pathognomonic of a vertical root fracture.

  7. In regenerative endodontic procedures (REP), blood clot scaffold creation requires instrumentation to what level?

    Answer: 1mm beyond the apex to induce bleeding

    Files or instruments are intentionally extended 1–2mm beyond the apex to lacerate periapical tissues and induce bleeding into the canal space to form a blood clot scaffold.