What should I do about bad breath caused by tooth decay?

To treat bad breath caused by tooth decay, maintain good oral hygiene by brushing teeth in the morning and at night, rinsing after meals, using dental floss to clean between teeth, and having regular professional teeth cleanings. Additionally, pay attention to dietary habits by reducing intake of sweets and carbonated beverages, and increasing consumption of fiber-rich foods. If the bad breath is caused by bacteria on the tooth surface, use fluoride toothpaste and fluoride mouthwash to inhibit bacterial growth. Consider using chlorhexidine-containing mouthwash to eliminate oral odor.