Metronidazole and tinidazole belong to the nitroimidazole class of drugs, with activity against a wide range of anaerobic bacteria, and both have a therapeutic effect on gingival swelling and pain. In comparison, the effective concentration of tinidazole lasts longer. 1. Metronidazole: the main component is 2-methyl-5-nitroimidazole-1-ethanol, which has a killing effect on anaerobic bacteria, and can be used for the treatment of anaerobic infections caused by periodontitis or periapical periodontitis caused by gingival swelling and pain. Common adverse reactions are gastrointestinal reactions, such as nausea, abdominal pain, etc. It is contraindicated in pregnant and lactating women. 2. Tinidazole: the main component is 2-methyl-1-[2-(ethylsulfonyl)ethyl]-5-nitro-1H-imidazole, has a strong anti-anaerobic effect on gingival swelling and pain has a certain therapeutic effect, and its adverse effects are similar to metronidazole. Tinidazole is higher than metronidazole blood concentration after oral administration, and the effective concentration lasts for a long time. All of the above drugs need to be used under the guidance of a doctor, it is recommended to go to the hospital to receive regular treatment.