Periodontics · single question
Which bacteria is NOT present in CHRONIC PERIODONTITIS? (EXCEPT)
Show answer and explanation
Correct answer: A. Aerobic Gram-positive bacteria
Chronic periodontitis is dominated by ANAEROBIC Gram-negative bacteria (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola — the red complex). AEROBIC GRAM-POSITIVE bacteria (Streptococcus) are associated with HEALTH and GINGIVITIS — they decrease as periodontitis progresses. They are the organisms NOT found predominantly in chronic periodontitis.
- A. Incorrect (ARE present). Anaerobic Gram-negative bacteria are the PRIMARY pathogens in chronic periodontitis.
- B. Incorrect (ARE present). Some anaerobic Gram-positive bacteria are found in periodontitis.
- C. CORRECT. Aerobic Gram-positive organisms are associated with health/gingivitis — outcompeted by anaerobes as periodontitis advances.
- D. Incorrect (ARE present). Motile spirochetes (Treponema denticola) are part of the red complex and found in deep pockets.