NBDE Periodontics 5

Question 1

Periodontal maintenance therapy (supportive periodontal therapy) intervals are typically set at every 3 months because:

Accepted Answer

Subgingival microbiota recolonize to pre-treatment levels in approximately 9–11 weeks

Answer

Studies show subgingival microbiota recover to pathogenic composition in roughly 9–11 weeks, making 3-month intervals clinically justified.

Question 2

Which of the following best characterizes plaque-induced gingival disease modified by medication?

Accepted Answer

Inflammatory overgrowth exacerbated by calcium channel blockers, phenytoin, or cyclosporine

Answer

Drug-influenced gingival enlargement is a well-documented adverse effect of calcium channel blockers, phenytoin, and cyclosporine, superimposed on pre-existing plaque-induced inflammation.

Question 3

The 'red complex' bacteria most strongly associated with severe chronic periodontitis includes:

Accepted Answer

Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola

Answer

Socransky's red complex—P. gingivalis, T. forsythia, and T. denticola—are most strongly associated with deep pockets and severe periodontal destruction.

Question 4

A 5 mm infrabony defect is treated with an open-flap debridement alone. The most likely type of healing is:

Accepted Answer

Long junctional epithelium repair

Answer

Without a membrane or graft, healing occurs predominantly by long junctional epithelium formation (repair), not true regeneration.

Question 5

Tetracycline is used as an adjunct in aggressive periodontitis primarily because it:

Accepted Answer

Achieves GCF concentrations 2–10× higher than serum and inhibits Aa

Answer

Tetracycline concentrates in gingival crevicular fluid at levels far exceeding serum, making it effective against Aggregatibacter actinomycetemcomitans in aggressive periodontitis.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Periodontics 5