Many people have a preliminary understanding of periodontal disease, so how long does it take to treat? How is it treated? The treatment of periodontal disease, especially periodontitis, is generally a comprehensive treatment approach, which means that multiple aspects and methods are combined, while the treatment of periodontitis is planned and carried out in a certain order. The treatment procedure usually consists of four phases: periodontal basic treatment, periodontal surgical treatment, periodontal restorative treatment, and periodontal supportive treatment. Periodontal basic treatment is the first stage of periodontal treatment: it has a very important role. In this stage, conventional treatment is applied to eliminate all possible pathogenic factors and to eliminate and control the inflammation of periodontal tissues. It includes teaching and guiding patients to perform self plaque control, trying to persuade them to quit smoking, routine supragingival scaling, subgingival scraping root planing, necessary treatment of the dental pulp, necessary occlusal adjustment, extraction of affected teeth without retention value, necessary medication, etc., which usually takes 1 to 2 months to complete. Four to six weeks after the completion of the basic treatment, the overall periodontal condition of the oral cavity should be re-examined and evaluated to observe the response to the previous treatment and the patient’s compliance. To determine the next step of treatment plan. Periodontal surgical treatment is the second stage of periodontal treatment: generally at I-3 months after the basic treatment, the periodontal condition is re-evaluated comprehensively, including plaque control, periodontal pocket depth, bleeding on probing, alveolar bone morphology, etc. If there are periodontal pockets larger than 5 mm with bleeding on probing or abnormal gingival morphology that requires revision, the type of periodontal surgery can be selected based on the specific situation and location. Do not undergo periodontal surgical treatment without basic periodontal treatment and without good control of inflammation. The restorative periodontal treatment stage is the third stage of periodontal treatment: it is usually performed 2 to 3 months after periodontal surgery. Because the morphology and position of periodontal tissues are basically stable at this time, permanent restorative treatment and fixation of loose teeth can be performed. Patients who need orthodontic treatment can also be performed in this period. Periodontal support therapy is the fourth phase of periodontal treatment: also known as the maintenance phase, it is a very important phase that is carried out throughout the treatment process. Regular review is emphasized to check the patient’s plaque control, gum inflammation, periodontal pocket depth, changes in the alveolar bone, and control of risk factors. Problems are identified and necessary re-treatment is performed. The doctor will determine the interval of the review for each patient according to the specific situation of each patient. Usually, a review is required once in 3 to 6 months, and an X-ray is taken about once a year. In conclusion, the treatment of periodontal disease is a meticulous and patient work. And requires close cooperation between the doctor and patient, persistent persistence, in order to obtain satisfactory, stable and long-term results.