It is useless to take metronidazole for periodontitis, which can be treated with basic treatment, local medication, and surgery. Metronidazole is not a routine drug for periodontitis, and is only used as an adjunctive drug in severe periodontitis and the presence of periodontal abscesses. 1. Basic treatment: The basic treatment of periodontal disease is scaling, scraping and root planing. It is necessary to remove tartar completely, using scaling for supragingival tartar and scraping for subgingival calculus. Root planing, scraping the diseased bone contaminated by toxins, thus removing the irritants that cause gingival inflammation and creating conditions conducive to periodontal adhesion healing. 2. Local medication: After the basic treatment, mouthwash containing antibiotics or anti-inflammatory ingredients can be used, such as mouthwash containing metronidazole and cotrimoxazole rinse. Creams containing antibiotics applied directly to the gap between the gums and teeth can effectively inhibit bacteria, such as minocycline gel, tetracycline gel and so on. 3. Surgical methods: flap surgery, the purpose of which is to make the periodontal pockets shallower or eliminate them. The gingiva is cut and then flipped to expose the root and alveolar bone, and subgingival cleaning and root surface leveling are performed, as well as alveolar bone trimming. If you have periodontitis, it is recommended that you go to a regular hospital for treatment, and medication should be prescribed by your doctor.