NBDE Periodontics and Endodontics 4

Question 1

Which bacteria is considered a MAJOR periodontal pathogen and is characteristically associated with rapidly progressing periodontitis?

Accepted Answer

Porphyromonas gingivalis

Answer

Porphyromonas gingivalis is a Gram-negative anaerobic rod considered a keystone periodontal pathogen due to its ability to evade host defenses and produce destructive proteases.

Question 2

What type of root resorption occurs from the outside of the root inward and is often associated with trauma or orthodontic treatment?

Accepted Answer

External inflammatory resorption

Answer

External inflammatory resorption occurs on the outer root surface, commonly triggered by trauma, orthodontic forces, or periapical infection stimulating osteoclastic activity.

Question 3

Which material is used as the gold standard for root canal obturation?

Accepted Answer

Gutta-percha with sealer

Answer

Gutta-percha combined with an endodontic sealer remains the gold standard for root canal obturation due to its biocompatibility, dimensional stability, and ease of removal if retreatment is needed.

Question 4

A patient taking phenytoin for seizure disorder is MOST likely to develop which periodontal complication?

Accepted Answer

Drug-influenced gingival enlargement

Answer

Phenytoin (Dilantin) is one of the classic drugs causing drug-influenced gingival enlargement (overgrowth), along with cyclosporine and calcium channel blockers.

Question 5

What does the term 'weeping canal' indicate clinically?

Accepted Answer

Persistent exudate from the canal indicating active infection

Answer

A weeping canal refers to persistent exudate (usually serous or purulent) flowing from the root canal, indicating active periapical infection requiring further debridement before obturation.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Periodontics and Endodontics 4