Dental calculus is relatively common, but it is not normal to have dental calculus, which can cause many oral problems. 1. The formation of dental calculus may be caused by poor oral hygiene, food residues, mineral deposits and bacterial growth. Calculus is the calcified plaque and tartar deposits attached to the surface of the teeth, the main component of which is calcium phosphate, and its clinical manifestation is yellow, brown or gray-black spots or blocks. 2. If the calculus is not removed in time, it will accumulate for a long time and cause the destruction of the periodontal tissues in the patient’s oral cavity, and in severe cases, it will lead to loosening of the patient’s teeth and require extraction, which will reduce the patient’s quality of life. Therefore, patients with dental calculus should go to the hospital in time, early treatment, to avoid the oral cavity hidden danger caused by the seriousness of dental calculus.