BEST DENTIST IN TAMIL NADU! Acid reflux, or more accurately, gastroesophageal reflux disease (GERD) is when stomach fluids flow up the esophagus into your mouth. This is highly acidic and contributes to a dry mouth and bad breath. If you suspect that your breath is off-putting to others, schedule a checkup. In just minutes we at Apple Dental can assess your oral hygiene and determine not only the cause of your bad breath, but provide a care plan to eliminate it.