Periodontal disease caused by calculus is treated with scaling and root planing, and the need for subsequent treatment is decided after the local irritants are removed. The treatment of periodontitis is generally divided into four stages: basic treatment, periodontal surgery, restorative treatment and periodontal support treatment. 1. Basic treatment stage: Scaling and root planing are performed to eliminate pathogenic factors and control gingival inflammation. Oral hygiene education is provided to the patients to educate and guide them to establish correct brushing methods and habits. 2. Periodontal surgical treatment stage: Generally, 4 to 12 weeks after the basic treatment, the periodontal condition will be comprehensively reevaluated to decide whether periodontal surgical treatment is needed. Surgeries include: flap surgery, bone grafting, guided tissue regeneration, membrane gingival surgery and dental implantation. 3. Restorative treatment phase: usually begins 2 to 3 months after periodontal surgery. 4. Periodontal supportive therapy: an indispensable part of a formal periodontal treatment program and a prerequisite for long-term maintenance of periodontal efficacy. From the first stage of treatment, regardless of the number of subsequent treatment components, periodontal maintenance treatment should be started. When periodontal disease is caused by dental calculus, it is important to go to a regular hospital as soon as possible and cooperate with a professional doctor to avoid delays.