Er：YAG laser is a new type of laser-powered hydrokinetic system belonging to middle infrared lasers, which has the suitable characteristics of oral soft tissues resection. In contrast with the traditional method, Er：YAG laser has many advantages, including ease pain and discomfort in the course of treatment, which the patients are more likely to accept. Er：YAG laser is being gradually studied and applied for dentistry. The article summarized the working principle of Er：YAG laser, as well as the advantages and application in oral therapy.
