Bad breath after dentures may be caused by improperly worn dentures or problems with denture materials, and may gradually disappear after replacing denture materials or removing dentures. However, bad breath is not entirely caused by wearing dentures, but may also be caused by the patient’s failure to properly clean and preserve the dentures. Usually, poor oral hygiene, food stuffing and oral bacterial infection can be the main causes of bad breath. Patients are advised to brush their teeth correctly, improve their dietary habits, and need to actively treat primary bacterial infections.1. Clean mouth: Patients wearing removable dentures should actively clean their dentures in the morning, before bedtime, and after meals, and like normal brushing, mouthwash can be used for cleaning in the mouth. Removable dentures should be taken off and soaked in cold water before bedtime, or under the guidance of a doctor for regular denture cleaner soaking and disinfection and descaling. Patients with inlaid dentures should ensure that they brush their teeth carefully for about 3 minutes each time, while choosing a toothbrush with softer bristles to avoid damaging the teeth and denture surfaces. After meals, you should use toothpicks or dental floss to clean the food residues embedded in the teeth in time to avoid the growth of dental bacteria; 2, improve dietary habits: garlic, onions, raw onions, chili peppers and other irritating foods, as well as smoking, drinking alcohol, drinking strong tea, drinking coffee or milk can cause bad breath, so whether wearing dentures or not, you should actively rinse your mouth and brush your teeth after ingesting the above diet to avoid food residues that cause bacteria Treatment of primary disease: Since bacterial infection can cause dental caries, pulpitis, periodontitis, gingivitis and other diseases, which often lead to bad breath, patients need to use antibacterial solutions such as hydrogen peroxide solution, chlorhexidine gargling treatment as prescribed by the doctor while improving hygiene habits, and oral antibacterial treatment with metronidazole, doxycycline, amoxicillin and other drugs. In case of local abscess, incision and drainage may be required, while patients with dental calculus also need to be removed by scraping or scaling.