Free NBDE Periodontics Questions and Answers — 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?
- 3 mm
- 2 mm
- 5 mm
- 7 mm (Correct answer)
Correct answer: 7 mm
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?
- Actinomyces naeslundii, Streptococcus mitis, Veillonella parvula
- Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola (Correct answer)
- Aggregatibacter actinomycetemcomitans, Capnocytophaga gingivalis, Eikenella corrodens
- Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus
Correct answer: Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola
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?
- Chronic Periodontitis
- Necrotizing Ulcerative Periodontitis (NUP)
- Localized Aggressive Periodontitis (LAP) (Correct answer)
- Gingivitis associated with dental plaque
Correct answer: Localized Aggressive Periodontitis (LAP)
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:
- Drug-induced gingival enlargement (Correct answer)
- Hormonal-influenced gingivitis
- Hereditary gingival fibromatosis
- Inflammatory gingival enlargement due to plaque
Correct answer: Drug-induced gingival enlargement
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:
- Polish the enamel surfaces for aesthetic improvement.
- Regenerate lost alveolar bone and periodontal ligament.
- Remove plaque, calculus, and endotoxins to create a biologically compatible root surface. (Correct answer)
- Whiten the teeth by removing extrinsic stains.
Correct answer: Remove plaque, calculus, and endotoxins to create a biologically compatible root surface.
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.
Question 6: During a periodontal examination of a maxillary molar, a Nabers probe passes completely through the furcation from the buccal to the mesial aspect, but the furcation entrance is not clinically visible due to being covered by gingival tissue. According to Glickman's classification, what is the grade of this furcation involvement?
- Grade I
- Grade IV
- Grade III (Correct answer)
- Grade II
Correct answer: Grade III
Glickman's Grade III furcation involvement describes a "through-and-through" lesion where the probe can pass entirely from one side of the furcation to the other. It is distinguished from Grade IV, where the through-and-through furcation is also clinically visible due to gingival recession.
Free NBDE Periodontics Questions and Answers
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?