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Crown-Root Ratio FPD — NDEB AFK MCQ

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EasyProsthodonticsCrown-Root Ratio FPDNDEB AFK

Which of the following Crown-Root ratios is generally considered the minimum acceptable for an abutment tooth in a fixed partial denture?

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

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Correct answer: E — 1:1

A crown-to-root ratio of 1:1 is generally considered the minimum acceptable for an abutment tooth in fixed prosthodontics. The optimal ratio is 1:2 (root length twice the crown length). As the crown-to-root ratio increases (shorter root, longer crown), the lever arm increases, concentrating stresses at the alveolar crest and increasing the risk of abutment failure. Periodontal bone loss effectively worsens the crown-to-root ratio by reducing the functional root length.

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