Cavities are clinically known as dental caries, and bad breath caused by dental caries mainly requires the removal of decayed and necrotic dental tissues, followed by filling. 1. Caries cavities are easy to retain food residues, not timely cleaned out will ferment, breeding bacteria, especially anaerobic bacteria decomposition produces sulfide, the release of odor, will cause bad breath. The main treatment is the treatment of dental caries, that is, you need to remove the corruption of necrotic dental tissue, and then filling. 2. At the same time, daily oral hygiene should be maintained, diligent brushing, rinsing, regular oral examination to avoid the recurrence of dental caries. Bad breath caused by dental caries is recommended to go to the hospital in a timely manner, under the guidance of the doctor to give targeted treatment or treatment.