Abstract: Objective: To study the expression of TRPAl in the dental pulp of dentin hypersensitivity teeth after mechanical stimuli. Methods: Cavities were prepared in the lower incisors of rats. After dentin exposure, dentin hypersensitivity test was performed by probe stimulation on dentin surface everyday. After 7 days, the dentin surface was observed by scanning electron microscopy (SEM). The dental tissue was harvest and underwent further RT-PCR and Western Blot analysis to investigate the expression of TRPAl in dental pulp. Results: After tooth preparation, most of dentinal tubules were open without pulp exposure. The rats of two stimulation groups appeared dentin hypersensitivity reaction behavior. The scores were significantly higher than that of the control group (P<0.01), and the intensity was increased with the intense of the behavioral reaction. The expression of TRPA1 mRNA and protein were significantly increased in the dental pulp of two stimulation groups, which was more significant with the increase of intensity of stimulation. Conclusion: TRPA1 may be an important pathogenesis factor of dentin hypersensitivity involved with mechanical stimuli.

Key words: Dentin hypersensitivity, Mechanical stimulation, TRPAl