Dental calculus can lead to bleeding teeth, tooth pain and loosening, and in severe cases can cause tooth loss and other hazards. Calculus is the causative factor of periodontal disease, if it is not removed in time by scaling or scraping, it will lead to red, swollen and bleeding gums, bleeding from brushing, and trigger gingivitis or periodontitis. Deep periodontal pockets appear around the teeth, and retrograde bacterial infection leads to pain in the teeth, such as pain in eating, destruction of periodontal supportive tissues, resorption of bone tissues, and loosening of the teeth, which can lead to tooth loss in severe cases. So calculus is very harmful to the teeth, not only cause teeth bleeding pain, but also lead to tooth loss, need to be removed in time, need to go to the hospital dental scaling or periodontal treatment.