NBDE Periodontics 3

Question 1

Which microorganism is most strongly associated with localized aggressive periodontitis (formerly localized juvenile periodontitis)?

Accepted Answer

Aggregatibacter actinomycetemcomitans

Answer

Aggregatibacter actinomycetemcomitans (Aa) is the primary pathogen in localized aggressive periodontitis, found in up to 90% of affected sites.

Question 2

A free gingival graft harvested from the palate primarily provides which benefit?

Accepted Answer

Increases zone of attached gingiva

Answer

Free gingival grafts are used primarily to widen the zone of keratinized/attached gingiva in areas of inadequate tissue.

Question 3

Chlorhexidine gluconate reduces supragingival plaque primarily through which mechanism?

Accepted Answer

Disrupting bacterial cell membranes via electrostatic binding

Answer

Chlorhexidine's cationic molecule binds to negatively charged bacterial cell membranes, altering permeability and causing cell death.

Question 4

Which of the following best describes the biologic width?

Accepted Answer

The combined dimension of junctional epithelium and supracrestal connective tissue attachment

Answer

Biologic width (~2 mm) is the combined height of the junctional epithelium (~1 mm) and supracrestal connective tissue attachment (~1 mm).

Question 5

Osseous resective surgery is most indicated when the goal is to:

Accepted Answer

Create a positive architecture by eliminating infrabony defects

Answer

Osseous resective surgery reshapes bone to create a positive (scalloped) architecture that allows better plaque control.

NBDE - National Board Dental Examination Practice Test