AGD Endodontic Diagnosis and Treatment 5 — Questions and Answers
Question 1: Which classification system is used to describe the complexity of root canal anatomy based on canal configuration?
- Black's classification
- Vertucci's classification (Correct answer)
- Angle's classification
- Kennedy's classification
Correct answer: Vertucci's classification
Vertucci's classification describes eight canal configuration types based on how canals originate, divide, and terminate within the root.
Question 2: A patient with an acute alveolar abscess presents with facial cellulitis and difficulty swallowing. What is the MOST urgent concern?
- Prescribing antibiotics only and scheduling RCT next week
- Monitoring pain levels with analgesics
- Airway compromise from spreading infection such as Ludwig's angina (Correct answer)
- Placing a temporary restoration
Correct answer: Airway compromise from spreading infection such as Ludwig's angina
Spreading odontogenic infection to the floor of the mouth (Ludwig's angina) can rapidly compromise the airway and is a life-threatening emergency.
Question 3: External cervical resorption (ECR) differs from internal root resorption (IRR) radiographically because ECR:
- Appears centered within the root canal and moves with the canal on CBCT
- Appears eccentric to the canal and the canal outline remains intact through the lesion (Correct answer)
- Is always associated with a periapical lesion
- Only occurs in non-vital teeth
Correct answer: Appears eccentric to the canal and the canal outline remains intact through the lesion
In ECR, the root canal remains intact and the resorptive defect is external; on CBCT, the canal outline can be traced through the lesion, unlike IRR.
Question 4: The 'Schilder technique' in root canal obturation is characterized by:
- Single-cone cold lateral condensation
- Warm vertical compaction using heated pluggers (Correct answer)
- Carrier-based thermoplasticized gutta-percha injection
- Cold lateral condensation with multiple accessory cones
Correct answer: Warm vertical compaction using heated pluggers
The Schilder technique uses sequentially heated pluggers and vertical compaction to densely obturate the canal system with warm gutta-percha.
Question 5: Calcium hydroxide is used as an intracanal medicament between appointments primarily because it:
- Softens gutta-percha for easier removal
- Creates a highly alkaline pH that kills anaerobic bacteria (Correct answer)
- Removes the smear layer from canal walls
- Stimulates immediate hard tissue bridge formation
Correct answer: Creates a highly alkaline pH that kills anaerobic bacteria
Calcium hydroxide dissociates to produce hydroxyl ions, raising pH to approximately 12.5, which disrupts bacterial cell membranes and enzyme function.
Question 6: Which of the following BEST describes the working length (WL) used in root canal treatment?
- Length from the cusp tip to the radiographic apex
- Length from a coronal reference point to 0.5–1 mm short of the radiographic apex (Correct answer)
- Length from the canal orifice to the cemento-dentinal junction
- Length of the longest file that fits passively to the apex
Correct answer: Length from a coronal reference point to 0.5–1 mm short of the radiographic apex
Working length is measured from a stable coronal reference point to approximately 0.5–1 mm short of the radiographic apex, near the apical constriction.
Question 7: Which sealer is the BEST choice when post space will be needed immediately after obturation?
- Calcium hydroxide-based sealer
- MTA-based sealer
- Zinc oxide–eugenol sealer (e.g., Pulp Canal Sealer) (Correct answer)
- Bioceramic sealer (e.g., BC Sealer)
Correct answer: Zinc oxide–eugenol sealer (e.g., Pulp Canal Sealer)
Zinc oxide–eugenol sealers remain soluble and can be dissolved by solvents, allowing easier post space preparation without damaging the apical seal.
AGD Endodontic Diagnosis and Treatment 5
Which classification system is used to describe the complexity of root canal anatomy based on canal configuration?