Dental calculus can cause bad breath. Tartar is a yellow dry stone-like substance formed by the mineralization of bacteria, soft scale, food residue, etc. attached to the tooth surface over a period of time, which is not easy to remove after formation and is bacterial in nature, while the rough surface makes it easier for plaque, etc. to accumulate, thus forming a vicious circle. After the formation of calculus, not only can it not be removed by brushing, which hinders the cleaning of teeth, but also makes bacteria and other close contact with gum tissue, causing a series of inflammatory reactions, which will not only lead to bad breath, but also cause plaque, gingivitis, periodontitis and other diseases, affecting the health condition of teeth. The appearance of dental calculus can go to dentistry or periodontology for ultrasonic dental cleaning. In daily life, you should also pay attention to oral hygiene, regularly clean your teeth, at least brush your teeth in the morning and evening, rinse your mouth after meals, do not eat again before going to bed, etc.