Sensitivity of dentin to chemical stimuli

Abstract Numerous chemical stimuli have been used to click pain from exposed dentin. Most of the effective chemicals share a common denominator; they arc all very hypertonic. Dentin surfaces covered with a smear layer are much less responsive to hypertonic solutions than dentin devoid of a smear layer. These observations support the hydrodynamic theory of dentin sensitivity. The most important variables influencing the efficacy of chemical stimuli include: ionic composition, presence or absence of calcium, sodium or potassium, pH and osmolality (tonicity). Although hypertonic solutions of sucrose or CaCl₂ can be useful qualitative stimuli, the theoretical objections to using them for quantitative evaluation of dentinal sensitivity seem to far out‐weight their advantages.