AGD Endodontic Diagnosis and Treatment 4 — Questions and Answers
Question 1: Vertical root fracture (VRF) in an endodontically treated tooth most characteristically shows which radiographic finding?
- Widened periodontal ligament space only at the apex
- A 'halo' or 'J-shaped' periapical radiolucency along the root (Correct answer)
- Internal root resorption
- Hypercementosis at the apex
Correct answer: A 'halo' or 'J-shaped' periapical radiolucency along the root
Vertical root fractures often present with a 'halo' or 'J-shaped' radiolucency along the lateral aspect of the root due to bone loss on both sides.
Question 2: Mineral trioxide aggregate (MTA) is the preferred material for apexification in immature permanent teeth because it:
- Sets rapidly and does not require moisture
- Induces cementum-like hard tissue and is biocompatible (Correct answer)
- Is easier to place than calcium hydroxide
- Is less expensive than other alternatives
Correct answer: Induces cementum-like hard tissue and is biocompatible
MTA creates an apical plug, induces hard tissue formation, and demonstrates superior biocompatibility, making it ideal for apexification procedures.
Question 3: A patient develops paresthesia of the lower lip following extraction of a mandibular molar. Which nerve was most likely affected?
- Lingual nerve
- Long buccal nerve
- Inferior alveolar nerve (Correct answer)
- Mental nerve
Correct answer: Inferior alveolar nerve
The inferior alveolar nerve runs through the mandibular canal adjacent to molar roots; injury during extraction or endodontic intervention causes lower lip paresthesia.
Question 4: Which diagnostic test best differentiates a crack confined to enamel from one extending into the pulp?
- Cold thermal test
- Percussion test
- Bite test using a Tooth Slooth device (Correct answer)
- Transillumination alone
Correct answer: Bite test using a Tooth Slooth device
The Tooth Slooth bite test localizes which cusp is cracked; pain on release (rebound pain) suggests crack extension toward or into the pulp.
Question 5: In regenerative endodontics for immature necrotic teeth, the biological scaffold used to support tissue ingrowth is:
- MTA plug only
- A blood clot, platelet-rich plasma, or platelet-rich fibrin (Correct answer)
- Gutta-percha condensed to working length
- Calcium hydroxide paste
Correct answer: A blood clot, platelet-rich plasma, or platelet-rich fibrin
A blood clot or platelet concentrates serve as a scaffold for stem cell migration and tissue regeneration in revascularization procedures.
Question 6: During canal shaping, 'ledge formation' is most likely to occur when:
- Using large instruments in straight canals
- Using small stiff stainless steel files in curved canals without pre-curving (Correct answer)
- Irrigating excessively with NaOCl
- Using NiTi files in reciprocating motion
Correct answer: Using small stiff stainless steel files in curved canals without pre-curving
Stiff stainless steel files in curved canals tend to straighten against the outer wall, cutting a false step (ledge) that blocks access to the apex.
Question 7: The 'glide path' in rotary endodontics refers to:
- The final taper achieved after full instrumentation
- A smooth, reproducible path created to the working length before rotary instrumentation (Correct answer)
- The angle of file insertion into the canal orifice
- The radiographic outline of the root canal
Correct answer: A smooth, reproducible path created to the working length before rotary instrumentation
Establishing a glide path with small hand files before rotary instrumentation prevents torsional fracture by allowing rotary files to follow a pre-formed pathway.
AGD Endodontic Diagnosis and Treatment 4
Vertical root fracture (VRF) in an endodontically treated tooth most characteristically shows which radiographic finding?