2015 Volume 58 Issue 4 Pages 290-299
Purpose: Dentin hypersensitivity is characterized by short sharp pain arising from exposed dentin in response to various external stimuli. The stimuli cause the flow of dentinal fluid in dentinal tubules and trigger a painful sensation. To prevent pain from dentin hypersensitivity, it is suggested that either suppressing the nerve impulse or occluding the dentin tubules is effective. Zinc stearate has the ability to form a coating film. So we hypothesized that this compound could cover the dentin surface and prevent dentin hypersensitivity. The objective of this study is to evaluate the ability of this compound to seal human dentinal tubules, and to analyze the behavior of the compound in the dentinal tubules and on the dentin surface.
Materials and Methods: Human normal molars or premolars were collected and the dentin samples were obtained from these teeth (n=120). The samples were randomly divided into 3 groups: the zinc stearate dispersion liquid group as an experimental group (Zn-St, n=40) ; the aluminum lactate/disodium hydrogen phosphate solution group as a positive control group (Al-PO3, n=40) ; and the sorbitol solution group as a negative control group (Cont, n=40). All samples were brushed on the oral cavity side of the dentin samples by toothbrushes using zinc stearate dispersion liquid, aluminum lactate/disodium hydrogen phosphate solution, or sorbitol solution. The dynamics of each sample on the dentin surface and in the dentinal tubules were evaluated with a scanning electron microscope (SEM). Brushing was carried out every 6 hours in a day. The dentin samples were collected just after first brushing, before and after second brushing, before and after third brushing, and 24 and 36 hours after first brushing. At all times, dentin samples were set in the simulated oral cavity environments, which were reproduced the pulpal pressure and body motion in 37 degree saline.
Results: In the Zn-St group, the dentin surface was coated and the dentinal tubules were occluded. Also, there was zinc stearate in the dentinal tubules just after brushing. In the Al-PO3 group, there was deposition along with the dentinal tubules. In the Cont group, there was no change on the dentin surface or in the dentinal tubules.
Conclusion: Zinc stearate could cover the dentin surface and enter into the dentinal tubules by consecutive brushing. We suggest that zinc stearate would be useful as a dentin hypersensitivity treatment.
