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Carious Dentin Zones — NDEB AFK MCQ

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HardRestorative DentistryCarious Dentin ZonesNDEB AFK

Which of the following represents the correct order of the zones of carious dentin from the pulp outward?

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

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Correct answer: D — Zone of destruction → zone of bacterial invasion → zone of demineralisation → translucent zone → normal dentin

From the advancing front of the carious lesion (outermost) toward the pulp, the zones of carious dentin are: (1) Zone of destruction — decomposed dentin with bacterial invasion, no recognisable structure; (2) Zone of bacterial invasion — partially demineralised dentin with bacteria in tubules; (3) Zone of demineralisation (affected dentin) — demineralised but no bacteria, potentially remineralisable; (4) Translucent zone — intact dentin with tubules partially occluded by mineral crystals; (5) Normal dentin. The demineralised zone represents the boundary between 'infected' (must be removed) and 'affected' (can be preserved) dentin.

Reference: Heymann – Sturdevant's Art and Science of Operative Dentistry, 7th ed., 2019