Dentin hypersensitivity is the symptom that is often encountered in the clinic, and may be caused by incorrect tooth brushing, gingival recession, inappropriate diet, and other factors. It is generally accepted that the sensation of pain is associated with patent dentinal tubules not covered by the smear layer or the calcified dentin terminating on the root surface. Stimulus transmission across dentin in hypersensitive teeth may be mediated by a hydrodynamic mechanism. Some authors report that lasers may provide reliable and reproducible treatments in the dental field including the therapy of dentin hypersensitivity. Lasers have been shown to fulfill the requirements of Grossman’s criteria by being nonirritating to the pulp. Lasers used for the treatment of dentin hypersensitivity are divided into two groups: low power output lasers (He-Ne and GaAlAs) and middle power output lasers (Nd:YAG, CO2, Er:YAG, GaAlAs, and Er,Cr:YSGG). In this paper, some kinds of laser devises used for treating dentin hypersensitivity, and the mechanism and assessment on the pain reduction by lasers are described. The effectiveness ranged from 5.2% to 100%, which was dependent on the indications, the laser type, the parameters used and the laser techniques. The mechanism involved in laser treatment of dentin hypersensitivity is not always clear. In general, treatment efficacy of dentin hypersensitivity using lasers is higher than other methods, but it is less effective in severe cases. To select the best treatment of dentin hypersensitivity, it is necessary to first consider the severity of dentin hypersensitivity before laser use.

Keywords: dentin hypersensitivity, mechanism, pain reduction, He-Ne laser, GaAlAs laser, Nd:YAG laser, CO2 laser, Er:YAG laser, Er,Cr:YSGG laser