There are several side effects of ultrasonic treatment: 1. The high-frequency oscillation of ultrasonic waves will produce slight scratches on the surface of the enamel, resulting in roughness of the tooth surface and easy accumulation of plaque and exogenous pigments; 2. When removing subgingival calculus, the ultrasonic working head will stimulate the soft tissues of the gums and produce a lot of bleeding, which can cause gum recession; 3. When removing calculus in the root bifurcation or root surface depression area, ultrasonic cleaning can scrape away part of the dental bone, exposing the dentin tubules in the periodontal pockets and risking pulpitis; 3. When dealing with demineralized tooth surfaces, ultrasonic cleaning can cause sensitive symptoms in the neck of the teeth.