There is no such thing as the best solution for bad breath. Causes of bad breath include oral inflammation, Helicobacter pylori infection, chronic sinusitis, etc. It is recommended to give medication and surgical treatment according to different causes. 1. Oral inflammation: including gingivitis, periodontitis, dental caries and so on. When there is long-term inflammation stimulation in the oral cavity, it leads to increased secretion of oral mucosa, accompanied by bacterial infection causing the symptom of smelly saliva. Nitazole antibiotic treatment can be given, such as metronidazole, ornidazole, etc., used to fight the infection of anaerobic bacteria in the oral cavity. 2. Helicobacter pylori infection: Helicobacter pylori can exist in saliva and dental plaque, which can decompose the amines in the stomach, and the undesirable gases in the stomach are discharged during exhalation, which produces irritating halitosis. Drug treatment is often through metronidazole, amoxicillin and other two antibiotics, with omeprazole and other acid-suppressing class, bismuth potassium citrate and other bismuth-potassium drugs combined treatment. 3. Chronic sinusitis: chronic inflammation of the sinuses may lead to purulent secretions from the sinuses flowing into the mouth and throat through the nasal passages, triggering the symptom of foul-smelling saliva in the mouth. Treatment of local administration of nasal glucocorticoids, such as budesonide, mometasone furoate, etc., used to anti-inflammatory, anti-edema, to reduce the secretion of the sinuses, serious cases of feasible endoscopic sinus surgery. If the long-term symptoms of halitosis, it is recommended to go to the hospital for examination, to clarify the specific causes of halitosis, standardized treatment under the guidance of the doctor, the use of drugs need to follow the doctor’s instructions.