How does one prevent bad breath?

Prevention is key: Preventing is important, but to prevent it, you must look for the source. Start with a full exam by a dentist, including radiographs, soft and hard tissue exam, periodontal exam. I see the majority of malodor coming from periodontal disease. Smokers, coffee drinkers, pungent foods, sinusitis, nasal obstructions--many sources. Brush teeth and tongue, floss daily.Correct technique important.

Keep it clean!: As bad breath generally comes from a type of bacteria that inhabit your tongue, creating volatile sulfur compounds (vsc's) that really smell, brushing, flossing and using a tongue scraper regularly go a long way to reducing bad breath. Sometimes other medical problems may contribute to the bad breath, so if you have done the above 3 things for at least 3 weeks with no changes, see your doctor!