Peking University Team Proposes Ion Current Mechanism for Dentin Hypersensitivity, Desensitizing Material Clinical Trial Shows Effectiveness Within 1 Minute

*Image source: "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy"

DentalGoodNews | Recently, the team led by Deng Xuliang from Peking University School of Stomatology published a paper titled "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy" in Stomatology. The paper systematically proposes and demonstrates the ion current conduction mechanism of dentin hypersensitivity, expanding the theoretical framework of this disease from the bioelectrochemical perspective, providing a new perspective for developing novel desensitizing materials.

The research team stated that dentin hypersensitivity is a common clinical oral disease, characterized by brief and sharp pain in exposed dentin when subjected to thermal, mechanical, or chemical stimuli. For a long time, the field has primarily relied on the hydrodynamic hypothesis to explain the pain generation mechanism, which suggests that external stimuli trigger abnormal fluid flow within dentinal tubules, mechanically activating pulpal nerve endings. However, this hypothesis has limitations in explaining rapid pain induction by stimuli, chemical stimulus-induced pain, and certain clinical efficacy differences.

*Image source: "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy"

Based on this, starting from biological ion channel theory, the research team proposed that dentinal tubules may not be merely passive fluid channels, but biological nanochannels with ion selectivity and rectification characteristics. Through comparing biological ion channels and dentinal tubules in terms of structure, electrochemical properties, and signal transduction functions, they proposed viewing dentinal tubules as a type of "solidified" biological ion channel.

*Image source: "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy"

Through high-resolution electrochemical and electrophysiological measurements, the researchers experimentally characterized the electrochemical properties of dentinal tubules. The results showed that there exists an asymmetric potential gradient from the dentin surface toward the pulp direction on the inner wall of dentinal tubules, with an amplitude of approximately 50-100 mV. Under thermal, mechanical, and chemical stimulation conditions, trans-dentinal microcurrents in the range of 0.1-5 μA can be induced. The paper further indicates that different types of stimuli can influence directional ion migration behavior by modulating ion mobility, double-layer structure, or surface charge state, thereby forming measurable electrical signals.

*Image source: "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy"

Based on the above experimental evidence, the researchers constructed a unified "stimulus-current-pain" electrophysiological model. This model proposes that external stimuli generate trans-dentinal microcurrents by directly modulating ion dynamics within dentinal tubules. These currents can rapidly transmit to pulpal nerve endings and induce pain perception through depolarization processes. The researchers believe this model may provide a new mechanistic framework for explaining millisecond-level pain transmission and clinical phenomena that traditional theories struggle to explain.

Building upon the mechanistic research, the researchers further discussed the application potential of the ion current conduction mechanism in desensitizing treatment. The research proposes that desensitizing strategies based on this mechanism should suppress abnormal currents by modulating the surface potential of dentinal tubules. Under this conceptual guidance, the researchers showcased electrochemical regulation desensitizing materials represented by polyquaternium-10 (PQ-10) hydrogel. Clinical trial results showed that after application of this desensitizing agent, patients' VAS pain scores decreased from 7.2 to 2.1 within 1 minute, and the anti-sensitivity effect could last for more than half a year.

*Image source: "From Liquid Flow to Ion Flow: A New Paradigm of Dentin Hypersensitivity Mechanism and Electrochemical Regulation Strategy"

Based on the research findings, the researchers believe that the proposal of the ion current conduction mechanism is expected to provide a new theoretical perspective for mechanistic research and desensitizing treatment strategies for dentin hypersensitivity, and promote the field's development from a treatment approach focused primarily on physical occlusion toward modulating the electrochemical microenvironment of dentin.