Dentine Sensitivity — MFDS Part 1 MCQ

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ModeratePhysiologyDentine SensitivityMFDS Part 1

A patient experiences brief, sharp pain when cold air is directed onto exposed cervical dentine. The pain ceases immediately when the stimulus is removed, and examination excludes other dental pathology. Which theory is most widely accepted as explaining this response?

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Correct answer: D — Hydrodynamic theory

The correct answer is **A, hydrodynamic theory**. Thermal, evaporative, tactile or osmotic stimuli cause rapid movement of fluid within exposed, patent dentinal tubules. This fluid displacement mechanically activates pulpal nerve endings, particularly fast-conducting A-delta fibres, producing brief, sharp pain that stops when the stimulus is removed. Direct innervation proposes that nerves extend through dentinal tubules, but their distribution does not adequately explain sensitivity across dentine. Odontoblast transduction remains a proposed contributory mechanism rather than the standard best explanation. Gate control concerns modulation of pain transmission within the nervous system, not the initiation of dentinal pain. Vibration theory is not an accepted principal mechanism of dentine hypersensitivity.

Reference: Liu XX et al. Pathogenesis, diagnosis and management of dentin hypersensitivity: an evidence-based overview for dental practitioners. BMC Oral Health. 2020;20:220. https://pubmed.ncbi.nlm.nih.gov/32762733/