Endodontics · patient case question
All of the following are routes by which bacteria reach the pulp EXCEPT:
Patient case: The tooth that bled during shaping
demo: 38-year-old male
chief: Referred for root canal treatment of a mandibular molar with a necrotic pulp.
history: Unremarkable. No allergies.
meds: None.
findings: Tooth 19 fails to respond to cold and is tender to percussion. Access is completed and the canals are irrigated. Partway through cleaning and shaping the patient reports sudden severe pain and the operator notices brisk bleeding from the canal along with rapid swelling of the cheek. Separately, tooth 4 in the same patient shows a narrow radiolucency running along the lateral root surface and joining an apical radiolucency.
Show answer and explanation
Correct answer: C. Anachoresis through the bloodstream
- A. The retrograde periodontal route through lateral and accessory canals and the apical foramen is well recognised and produces combined endodontic-periodontal lesions.
- B. A fracture that exposes dentin opens tubules directly to the oral environment, and one that exposes pulp does so immediately.
- C. Correct as this question is keyed, and this is the exception. Anachoresis, the seeding of an inflamed pulp by circulating bacteria, is a documented experimental phenomenon but is a rare and debated route clinically. Caries is overwhelmingly the dominant pathway.
- D. Caries is the principal route. Bacteria and their products advance through dentinal tubules well before frank exposure.