Free NBDE Periodontics Questions and Answers

Question 1

A patient presents for a periodontal evaluation. The probing depth on the facial aspect of tooth #8 is 5 mm, and there is 2 mm of gingival recession. What is the Clinical Attachment Loss (CAL) at this site?

Accepted Answer

7 mm

Answer

Clinical Attachment Loss (CAL) is calculated from a fixed reference point, the Cementoenamel Junction (CEJ). When gingival recession is present, the CAL is determined by adding the probing depth to the amount of recession. In this case, 5 mm (probing depth) + 2 mm (recession) = 7 mm of CAL.

Question 2

Which of the following groups of bacteria, known as the "Red Complex," is strongly associated with severe and progressive forms of periodontitis?

Accepted Answer

Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola

Answer

The "Red Complex" is a group of three bacterial species—Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola—that are considered major pathogens in the development and progression of chronic periodontitis. The other groups listed contain bacteria associated with periodontal health or less severe forms of disease.

Question 3

A 22-year-old, systemically healthy patient presents with severe, rapid bone loss localized to the first molars and incisors. Clinical examination reveals deep periodontal pockets with minimal visible plaque and calculus. Which of the following is the most likely diagnosis?

Accepted Answer

Localized Aggressive Periodontitis (LAP)

Answer

Localized Aggressive Periodontitis (LAP) is characterized by rapid attachment and bone loss, an early age of onset, and a specific pattern of destruction typically affecting the first molars and incisors. A key feature is that the amount of microbial deposit is often inconsistent with the severity of the periodontal destruction.

Question 4

A patient taking nifedipine for hypertension presents with significant gingival enlargement, particularly in the anterior region. This condition is an example of:

Accepted Answer

Drug-induced gingival enlargement

Answer

Nifedipine is a calcium channel blocker well-known for causing drug-induced gingival enlargement. This condition is also commonly associated with other classes of drugs, including anticonvulsants (like phenytoin) and immunosuppressants (like cyclosporine).

Question 5

The primary therapeutic goal of scaling and root planing (SRP) is to:

Accepted Answer

Remove plaque, calculus, and endotoxins to create a biologically compatible root surface.

Answer

The main objective of scaling and root planing is to remove the etiologic agents of periodontitis, which include dental plaque, calculus (tartar), and bacterial toxins (endotoxins) from the root surfaces. This debridement helps reduce gingival inflammation and allows for the healing and reattachment of periodontal tissues to a clean, smooth root surface.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

Free NBDE Periodontics Questions and Answers