Endodontics · patient case question
Pain provoked by heat in a tooth with pulpal inflammation is carried predominantly by which fibers?
Patient case: Full-Mouth Pulpal Diagnosis
demo: 46-year-old female
chief: “Several of my teeth on the upper right have been bothering me in different ways.”
history: Non-contributory. No medications.
meds: None
findings: Tooth #2: no response to cold, painful to percussion and palpation, periapical radiolucency. Tooth #3: sharp pain to cold that lingers more than 20 seconds. Tooth #4: exaggerated but non-lingering response to cold, deep restoration. Tooth #5: pain on biting, tender to percussion, widened PDL at the apex.
Show answer and explanation
Correct answer: D. C fibers
- A. A-alpha fibers are large motor and proprioceptive fibers, not pulpal nociceptors.
- B. Sympathetic fibers regulate pulpal blood flow rather than transmitting nociception.
- C. A-delta fibers mediate the sharp cold and EPT response, not the heat response.
- D. Correct. C fibers have a high threshold and are activated as inflammation and intrapulpal pressure rise, producing the dull, lingering, heat-provoked pain typical of advanced pulpitis.