Gingival calculus is generally referred to as subgingival calculus, which is mainly removed by subgingival scaling, and usually needs to be combined with ultrasonic scaling to completely remove the calculus. Gingival calculus is mainly caused by calcified deposits of soft tartar on the surface of the teeth, and is divided into supragingival calculus and subgingival calculus, both of which can be treated with different ultrasonic equipment for supragingival cleaning and subgingival scraping, of which the subgingival scraping is mainly for patients with periodontal disease. The removal of calculus is mainly by utilizing the vibration, cavitation and mechanical effects of ultrasonic waves to shatter down the tartar as much as possible without damaging the teeth. Compared to traditional manual scaling and subgingival scraping, ultrasonic scaling is currently the most rapid, efficient and proven method. It is recommended that regular patients have regular supragingival scaling every 6-12 months, and periodontal patients have scaling every 3-6 months.