Gingival Retraction for Impressions — NDEB AFK MCQ
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Correct answer: E — Gingival retraction using retraction cord (impregnated with haemostatic/astringent agent) placed into the gingival sulcus before impression-taking
Gingival retraction is essential for accurate reproduction of subgingival crown margins. Retraction cord (braided or knitted) is placed into the gingival sulcus to laterally deflect the gingival tissue and control crevicular fluid. The cord is often impregnated with haemostatic/astringent agents (aluminium chloride, ferric sulfate, epinephrine — epinephrine-impregnated cord should be avoided in patients with cardiovascular disease). The cord is removed immediately before impression material injection, allowing the material to flow into the expanded sulcus and capture the preparation margin.
Reference: Shillingburg – Fundamentals of Fixed Prosthodontics, 4th ed., 2012