ADEX Periodontal Concepts 3 — Questions and Answers
Question 1: Which bacterium is considered the primary etiologic agent of localized aggressive periodontitis (now classified as Stage III/IV Grade C in young patients)?
- Porphyromonas gingivalis
- Aggregatibacter actinomycetemcomitans (Correct answer)
- Tannerella forsythia
- Fusobacterium nucleatum
Correct answer: Aggregatibacter actinomycetemcomitans
Aggregatibacter actinomycetemcomitans (Aa) produces leukotoxin and is classically associated with localized aggressive periodontitis in young patients.
Question 2: What is the histologic hallmark that distinguishes a periodontal pocket from a gingival sulcus?
- Presence of junctional epithelium
- Apical migration of the junctional epithelium with loss of connective tissue attachment (Correct answer)
- Increased sulcular fluid flow
- Presence of subgingival calculus
Correct answer: Apical migration of the junctional epithelium with loss of connective tissue attachment
A true periodontal pocket forms when the junctional epithelium migrates apically beyond the CEJ, resulting in loss of connective tissue attachment and alveolar bone.
Question 3: A patient has 30% bone loss, 6 mm probing depths, and tooth mobility. According to the 2017 AAP classification, which Stage of periodontitis best fits this presentation?
- Stage I
- Stage II
- Stage III (Correct answer)
- Stage IV
Correct answer: Stage III
Stage III periodontitis is characterized by ≥30% bone loss, probing depths ≥6 mm, and tooth mobility, indicating severe disease with potential for tooth loss.
Question 4: Which cytokine, produced by macrophages, is a key mediator of bone resorption and connective tissue destruction in periodontitis?
- IL-10
- TGF-β
- IL-1β (Correct answer)
- IL-4
Correct answer: IL-1β
IL-1β is a pro-inflammatory cytokine produced by macrophages that stimulates osteoclast activity and upregulates prostaglandin E2, driving bone resorption.
Question 5: What is the primary composition of subgingival calculus that differentiates it from supragingival calculus?
- Calcium carbonate predominates
- Iron and magnesium phosphate give it a dark color; derives from gingival crevicular fluid (Correct answer)
- Fluoride compounds predominate
- It is composed primarily of organic matrix
Correct answer: Iron and magnesium phosphate give it a dark color; derives from gingival crevicular fluid
Subgingival calculus is dark brown or black due to blood pigments and derives its mineral content from gingival crevicular fluid rather than saliva.
Question 6: Furcation involvement in a mandibular first molar is classified as Class II when the probe can:
- Just detect the furcation entrance but not enter
- Enter the furcation but not pass through completely (Correct answer)
- Pass completely through the furcation
- Detect bone loss radiographically only
Correct answer: Enter the furcation but not pass through completely
Class II furcation means the probe can enter the furcation area but cannot pass through to the other side, indicating partial bone loss.
Question 7: Which tooth surface is most commonly the site for initial attachment loss in generalized periodontitis?
- Buccal surface at mid-tooth height
- Interproximal surfaces below the contact area (Correct answer)
- Palatal/lingual surfaces apical to the CEJ
- Facial surface at the mucogingival junction
Correct answer: Interproximal surfaces below the contact area
Interproximal surfaces are the most common site of initial attachment loss because plaque accumulates in the contact area and is most difficult to clean.
ADEX Periodontal Concepts 3
Which bacterium is considered the primary etiologic agent of localized aggressive periodontitis (now classified as Stage III/IV Grade C in young patients)?