DMD DMD Endodontics and Pulp Biology 1 — Questions and Answers
Question 1: Which zone of the pulp contains the cell bodies of odontoblasts?
- Cell-rich zone
- Cell-free zone (Weil's zone)
- Odontoblastic layer (Correct answer)
- Pulp core
Correct answer: Odontoblastic layer
The odontoblastic layer is the outermost zone of the pulp and contains the cell bodies of odontoblasts, which line the pulp-dentin border.
Question 2: Which test is most reliable for confirming pulp vitality?
- Cold test (thermal)
- Electric pulp test
- Percussion test
- Laser Doppler flowmetry (Correct answer)
Correct answer: Laser Doppler flowmetry
Laser Doppler flowmetry directly measures blood flow within the pulp, making it the most reliable vitality test, though it is not routinely available in clinical practice.
Question 3: Irreversible pulpitis is characterized by which symptom?
- Lingering pain after stimulus removal (Correct answer)
- Pain that subsides immediately after stimulus removal
- Absence of response to cold
- Spontaneous resolution of symptoms
Correct answer: Lingering pain after stimulus removal
Lingering pain (>30 seconds after stimulus removal) is the hallmark of irreversible pulpitis, indicating significant pulpal inflammation that cannot heal.
Question 4: What is the function of the Weil's (cell-free) zone in the pulp?
- It contains unmyelinated nerve fibers and capillaries but is relatively acellular, serving as a reserve for fibroblast migration (Correct answer)
- It forms secondary dentin
- It provides immune surveillance
- It directly transmits pain signals
Correct answer: It contains unmyelinated nerve fibers and capillaries but is relatively acellular, serving as a reserve for fibroblast migration
Weil's zone is a relatively acellular region just beneath the odontoblastic layer that contains fine nerve fibers and capillaries and serves as a reservoir for fibroblast migration during repair.
Question 5: Which type of dentin is formed in response to caries or trauma as a protective response?
- Tertiary (reparative) dentin (Correct answer)
- Primary dentin
- Secondary dentin
- Intertubular dentin
Correct answer: Tertiary (reparative) dentin
Tertiary dentin, also called reparative dentin, is rapidly formed by newly differentiated odontoblast-like cells in response to irritation such as caries or operative procedures.
Question 6: Which microorganism is most commonly found in primary endodontic infections?
- Streptococcus mutans
- Enterococcus faecalis
- Fusobacterium nucleatum
- Mixed anaerobic flora (Correct answer)
Correct answer: Mixed anaerobic flora
Primary endodontic infections are typically polymicrobial, predominantly composed of obligate anaerobes in a synergistic mixed flora.
DMD DMD Endodontics and Pulp Biology 1
Which zone of the pulp contains the cell bodies of odontoblasts?