Periodontitis is a disease that causes destruction of the tissues around the teeth (including the gums, periodontium, and alveolar bone) and is overlooked because there are no obvious symptoms of pain and discomfort in the early stages. The earliest symptoms of the disease are usually bleeding gums and bad breath. If left untreated or inadequately treated, the gums will gradually become repeatedly red and painful, and the teeth will loosen, elongate, shift, and eventually lead to tooth loss. Perfect periodontal system treatment includes three stages: periodontal basic treatment and periodontal surgical treatment and regular maintenance period treatment. Periodontal basic treatment includes supragingival scaling, subgingival scaling, and root surface leveling. The purpose of basic treatment is to remove the pathogenic factors of periodontitis in a progressive and in-depth manner to control the disease. Supragingival scaling is what we usually call scaling, which completely removes tartar and plaque from above the gums, and also removes large pieces of subgingival calculus visible to the naked eye; subgingival scaling is performed after supragingival scaling, gum inflammation improves, and gum bleeding improves, using finer instruments to remove tartar and plaque deep inside the periodontal pocket. If some patients do not have significant supragingival tartar but have significant subgingival tartar, subgingival scaling can be performed directly. Root surface leveling is performed under local anesthesia, using manual and overtime instruments to thoroughly remove calculus plaque deep in the periodontal pocket and infected bone on the root surface. After supragingival and subgingival scaling, inflammatory symptoms such as redness and bleeding of the gums will be significantly improved. If localized gum inflammation is still present at the time of review, or if the root surface is rough, root planing under local anesthesia is required. A follow-up visit for re-evaluation is required 6-8 weeks after basic periodontal treatment, and some patients and teeth may require further periodontal surgical treatment. The purpose of periodontal surgical treatment is to eliminate deep periodontal pockets, improve alveolar bone and gingival morphology, and restore and shape local conditions conducive to the patient’s self-maintenance of oral hygiene. After the basic periodontal treatment and surgical treatment, the patient can move to the periodontal maintenance phase of treatment. Patients should take active oral hygiene maintenance measures after the treatment, including the use of proper brushing methods and, if necessary, the use of dental floss and interdental brushes to prevent and reduce the formation of plaque and tartar on the teeth. Even so, there may be areas where plaque and tartar cannot be completely cleaned, which requires patients to undergo regular review and treatment, generally recommended every 4-6 months for periodontitis patients.