Bad breath caused by dental odor is the result of dental pathology, and the source of the problem should be addressed first. Dental diseases that can cause bad breath are dental caries, gingivitis, periodontitis and so on. Bad breath caused by dental caries, must go to the hospital in time to fill the teeth, and the sooner the better, do not delay. When treated early with mild symptoms and small cavities, there is a possibility that the living pulp will be preserved and the life span of the tooth will increase. If the bad breath is caused by periodontitis, it is also important to step up treatment. As the condition worsens, the periodontal pockets overflow with pus badly and the bad breath becomes more intense. Plaque and calculus can be removed and inflammatory substances can be cleaned up by scraping. Patients with bad breath caused by dental odors should adhere to regular dental cleanings, which can prevent and control periodontitis, as well as clean the mouth and remove bad breath.