Endodontics · single question
A patient has a necrotic tooth with a sinus tract and is allergic to penicillin. The patient also has a cardiac stent placed 2 months ago. What antibiotic do you prescribe?
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Correct answer: D. No antibiotic needed — treat the source (root canal or extraction)
A necrotic tooth with a sinus tract (a draining chronic abscess) does NOT require antibiotics — the sinus tract is already providing drainage. Antibiotics are indicated only when there is systemic involvement (fever, trismus, lymphadenopathy, cellulitis, or immunocompromise). The cardiac stent does NOT require antibiotic prophylaxis per AHA guidelines (prophylaxis is for specific cardiac conditions, not stents). The definitive treatment is eliminating the source (root canal therapy or extraction). Antibiotics without source control are inappropriate.
- A. Incorrect. Amoxicillin is contraindicated due to penicillin allergy. Additionally, antibiotics are not indicated for this presentation.
- B. Incorrect. While azithromycin is a penicillin-alternative, antibiotics are not indicated for a draining sinus tract without systemic spread.
- C. Incorrect. Clindamycin is a penicillin-allergy alternative but antibiotics are not necessary when a sinus tract is present and providing drainage.
- D. CORRECT. A sinus tract = drainage = no systemic spread. Antibiotics are NOT indicated. Stents do NOT require prophylaxis per AHA. Treat the source (extraction or RCT).