Effect of Dentin Desensitizers on Dentin Tubules Occlusion

—Influence of Dentin and External Stimulation—

Abstract

 Purpose: Hydrodynamic theory is influential as the pathogenic mechanism of dentin hypersensitivity. The healing ratio of conservation, one of the treatment methods for dentin hypersensitivity, was reported to be 60-70%. We considered that desensitizers, when used as a conservation material, did not show sufficient effectiveness on dentin due to certain influences. In this study, we investigated the influence of dentin on dentin desensitizers by observing the movement of liquid in dentinal tubules. In addition, we investigated the influence of liquid in dentinal tubules when drying stimulation was given on the dentin surface on which dentin desensitizers were applied.
 Methods: Four kinds of dentin desensitizer which are classified into the resin system and oxalic acid system were used. To investigate the influence of dentin on dentin desensitizers, the dentinal tubules with or without pulp pressure, as well as different liquids in dentinal tubules, were examined and the ratio of inhibition of liquid movement was calculated. Drying stimulation on the dentin surface was given and the ratio of inhibition of liquid movement was calculated.
 Results: The inhibition ratio decreased significantly when dentin desensitizers were applied with pulp pressure. With regard to the influence of drying stimulation, the inhibition ratio between the resin system and oxalic acid system showed a significant difference.
 Conclusion: Two types of dentin desensitizer, the resin system and the oxalic acid system, were influenced by pulp pressure, and the movement of liquid in dentinal tubules was influenced by drying stimulation on dentin desensitizers due to differences in sealing mechanisms.