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Xylitol Mechanism — NDEB AFK MCQ

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ModerateCommunity Dentistry & EpidemiologyXylitol MechanismNDEB AFK

Xylitol chewing gum has been shown to reduce dental caries risk primarily by which mechanism?

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

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Correct answer: B — Being non-fermentable by oral bacteria and inhibiting S. mutans metabolism

Xylitol is a five-carbon sugar alcohol that cannot be fermented by S. mutans (unlike six-carbon sugars such as glucose and fructose). S. mutans takes up xylitol but cannot metabolise it, creating a futile energy cycle that inhibits bacterial growth and acid production. Additionally, xylitol stimulates salivary flow (mechanical chewing stimulus), enhancing buffering and remineralisation. Clinical studies show 30-60% caries reduction with regular xylitol use (≥5g/day).

Reference: Fejerskov & Kidd – Dental Caries: The Disease and Its Clinical Management, 3rd ed., 2015