ORE Part 2 Periodontics 2 — Questions and Answers
Question 1: What is the recommended re-evaluation period after completing active non-surgical periodontal therapy (root surface debridement)?
- 2 weeks
- 4 weeks
- 8–12 weeks (Correct answer)
- 6 months
Correct answer: 8–12 weeks
The BSP/EFP guidelines recommend re-evaluation at 8–12 weeks after completing non-surgical therapy. This timeframe allows for tissue healing, resolution of inflammation, and maturation of the junctional epithelium. Earlier assessment may show false improvements due to residual oedema, while later assessment may miss the window for timely surgical intervention.
Question 2: A Class II furcation involvement in a mandibular molar is defined as:
- A horizontal probe penetration into the furcation not exceeding one-third of the buccolingual width
- A horizontal probe penetration exceeding one-third of the buccolingual width but not through-and-through (Correct answer)
- A through-and-through furcation defect
- No furcation involvement detectable
Correct answer: A horizontal probe penetration exceeding one-third of the buccolingual width but not through-and-through
Class II furcation involvement (Hamp classification) is defined as horizontal bone loss exceeding one-third of the buccolingual width of the tooth but without complete through-and-through penetration. It is clinically detectable with a curved Nabers probe and represents a significant treatment planning challenge due to limited access for debridement.
Question 3: Which surgical technique is most appropriate for treating an infrabony defect with a three-wall configuration?
- Gingivectomy
- Guided tissue regeneration (GTR) or enamel matrix derivative application (Correct answer)
- Apically repositioned flap
- Free gingival graft
Correct answer: Guided tissue regeneration (GTR) or enamel matrix derivative application
Three-wall (contained) infrabony defects have the best prognosis for regenerative therapy. Guided tissue regeneration (using a barrier membrane) or enamel matrix derivative (Emdogain) application can achieve new attachment formation including new cementum, periodontal ligament, and alveolar bone. The three-wall morphology provides natural containment for the regenerative material.
Question 4: What is the primary purpose of supportive periodontal therapy (SPT) after active treatment?
- To cure the disease permanently
- To maintain treatment outcomes and prevent disease recurrence through regular monitoring and reinforcement (Correct answer)
- To replace the need for daily oral hygiene
- To prepare the patient for implant placement
Correct answer: To maintain treatment outcomes and prevent disease recurrence through regular monitoring and reinforcement
SPT (maintenance therapy) is essential for long-term success after active periodontal treatment. It involves regular recall visits (typically 3-monthly initially) for professional mechanical plaque removal, reassessment of probing depths and bleeding, oral hygiene reinforcement, and early detection of disease recurrence. Without SPT, relapse rates are significantly higher.
Question 5: Smoking increases the risk of periodontal disease through which primary mechanism?
- Direct chemical destruction of tooth enamel
- Impaired neutrophil function and reduced gingival blood flow (Correct answer)
- Increased salivary flow causing plaque accumulation
- Stimulation of osteoblast activity
Correct answer: Impaired neutrophil function and reduced gingival blood flow
Smoking impairs the host immune response through multiple mechanisms: reduced neutrophil chemotaxis and phagocytosis, impaired antibody production, vasoconstriction reducing gingival blood flow (masking inflammation), and altered cytokine profiles favouring tissue destruction. Smokers also show reduced bleeding on probing despite active disease, making clinical assessment more challenging.
Question 6: Which index is most commonly used in UK clinical practice for recording plaque levels at the gingival margin?
- Quigley-Hein plaque index
- Silness and Löe plaque index
- O'Leary plaque control record (disclosing and recording presence/absence at 4 surfaces) (Correct answer)
- Turesky modification of the Quigley-Hein index
Correct answer: O'Leary plaque control record (disclosing and recording presence/absence at 4 surfaces)
The O'Leary plaque control record is the most widely used plaque index in UK clinical practice. After applying disclosing solution, the presence or absence of plaque is recorded at four surfaces per tooth, and a percentage plaque score is calculated. A target of less than 20% (ideally 10%) is considered acceptable for periodontal maintenance.
What is the recommended re-evaluation period after completing active non-surgical periodontal therapy (root surface debridement)?