NBDE Periodontics 2 — Questions and Answers
Question 1: Which furcation classification indicates that a probe can pass completely through the furcation from one side to the other?
- Class I
- Class II
- Class III (Correct answer)
- Class IV
Correct answer: Class III
Class III furcation involvement means the probe passes completely through the furcation, though it may still be covered by soft tissue.
Question 2: The junctional epithelium attaches to the tooth surface via which structures?
- Sharpey's fibers and cementum
- Hemidesmosomes and a basal lamina (Correct answer)
- Collagen fibers and elastin
- Oxytalan fibers and proteoglycans
Correct answer: Hemidesmosomes and a basal lamina
The junctional epithelium attaches to enamel and cementum through hemidesmosomes and an internal basal lamina.
Question 3: A patient has 6 mm probing depths, 2 mm of recession, and radiographic bone loss to the mid-root. What is the clinical attachment level (CAL)?
- 4 mm
- 6 mm
- 8 mm (Correct answer)
- 10 mm
Correct answer: 8 mm
CAL = probing depth + recession = 6 + 2 = 8 mm.
Question 4: Which systemic condition is most associated with aggressive generalized periodontitis in young patients due to neutrophil dysfunction?
- Type 2 diabetes mellitus
- Chediak-Higashi syndrome (Correct answer)
- Sjögren's syndrome
- Cushing's disease
Correct answer: Chediak-Higashi syndrome
Chediak-Higashi syndrome involves defective neutrophil chemotaxis and degranulation, predisposing to severe early-onset periodontitis.
Question 5: Scaling and root planing is best described as which type of periodontal therapy?
- Surgical phase
- Cause-related (etiotropic) phase (Correct answer)
- Corrective phase
- Maintenance phase
Correct answer: Cause-related (etiotropic) phase
Scaling and root planing is the cornerstone of cause-related (etiotropic) therapy, targeting the primary etiologic factor—bacterial plaque and calculus.
Question 6: Which periodontal fiber group runs from the alveolar crest obliquely to insert into cementum coronal to the crest?
- Horizontal fibers
- Oblique fibers
- Alveolar crest fibers (Correct answer)
- Apical fibers
Correct answer: Alveolar crest fibers
Alveolar crest fibers run from the alveolar crest obliquely upward to insert into cementum just apical to the CEJ.
Question 7: In the Armitage 1999 classification, which condition is characterized by rapid attachment loss in otherwise healthy young adults affecting multiple teeth?
- Chronic periodontitis
- Aggressive periodontitis (Correct answer)
- Necrotizing ulcerative periodontitis
- Periodontitis as a manifestation of systemic disease
Correct answer: Aggressive periodontitis
Aggressive periodontitis (generalized form) presents with rapid attachment loss in systemically healthy young adults and familial aggregation.
NBDE Periodontics 2
Which furcation classification indicates that a probe can pass completely through the furcation from one side to the other?