INBDE Endodontics 1 — Questions and Answers
Question 1: Which test is most reliable for diagnosing pulp necrosis?
- Thermal cold test
- Thermal heat test
- Electric pulp test (Correct answer)
- Percussion test
Correct answer: Electric pulp test
The electric pulp test (EPT) is used to assess pulp vitality and is most reliable for identifying pulp necrosis; a necrotic pulp will show no response.
Question 2: The apical constriction (minor diameter) of the canal is located approximately:
- At the radiographic apex
- 0.5–1.0 mm coronal to the anatomic apex (Correct answer)
- At the cemento-dentinal junction
- At the mid-root level
Correct answer: 0.5–1.0 mm coronal to the anatomic apex
The apical constriction, where the canal is narrowest, is located approximately 0.5–1.0 mm coronal to the anatomic apex and is the ideal endpoint for canal instrumentation.
Question 3: Sodium hypochlorite (NaOCl) is used as an irrigant in root canal therapy primarily because it:
- Chelates smear layer
- Dissolves organic tissue and has broad antimicrobial activity (Correct answer)
- Stimulates periapical healing
- Prevents instrument fracture
Correct answer: Dissolves organic tissue and has broad antimicrobial activity
Sodium hypochlorite is the primary root canal irrigant due to its ability to dissolve pulp tissue and its potent antimicrobial activity against endodontic pathogens.
Question 4: Vertical root fracture is most commonly associated with:
- Excessive irrigation pressure
- Excessive lateral condensation during obturation (Correct answer)
- Perforation with a post drill
- Trauma from occlusion
Correct answer: Excessive lateral condensation during obturation
Excessive lateral condensation pressure during cold lateral compaction of gutta-percha is a major cause of vertical root fracture.
Question 5: Gutta-percha is primarily composed of which material?
- Zinc oxide and eugenol
- Trans-polyisoprene (rubber), zinc oxide, and barium sulfate (Correct answer)
- Calcium hydroxide and silicone
- Resin and glass ionomer
Correct answer: Trans-polyisoprene (rubber), zinc oxide, and barium sulfate
Gutta-percha points consist primarily of trans-polyisoprene (gutta-percha resin), zinc oxide (filler), barium sulfate (radiopacifier), and waxes/resins.
Question 6: Which radiographic finding is most consistent with a diagnosis of condensing osteitis?
- Periapical radiolucency with diffuse borders
- Periapical radiopacity with diffuse borders (Correct answer)
- Loss of lamina dura
- Widened periodontal ligament space
Correct answer: Periapical radiopacity with diffuse borders
Condensing osteitis appears as a periapical radiopacity representing localized bone sclerosis in response to a low-grade inflammatory stimulus from the pulp.
INBDE Endodontics 1
Which test is most reliable for diagnosing pulp necrosis?