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Anti-Rotation Post Design — NDEB AFK MCQ

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ModerateEndodonticsAnti-Rotation Post DesignNDEB AFK

Which of the following correctly describes the concept of 'anti-rotation' in post-and-core restorations?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — An anti-rotation feature (keyway, slot, pin, or irregular canal shape) that prevents the post-and-core unit from rotating within the root canal

Anti-rotation is a design feature that prevents the post-and-core unit from spinning (rotating) within the root canal. Round posts in round canals have no inherent anti-rotation. Anti-rotation is achieved by: (1) using a canal shape that is naturally non-round (oval/irregular — custom cast posts conform to this shape); (2) adding a keyway or slot in the canal wall alongside a round prefabricated post; (3) using a secondary retention pin; or (4) using a non-round post design. Anti-rotation is essential for single-rooted teeth with minimal remaining coronal structure.

Reference: Shillingburg – Fundamentals of Fixed Prosthodontics, 4th ed., 2012