A. Bad breath- also known as halitosis is caused by many factors: 1. strong foods with odour- garlic, onions, curry etc 2. bad oral hygiene- ie not brushing and flossing regularly 3. Smoking 4. Not regularly drinking water to hydrate the oral cavity and wash away any food debris 5. Food trapping through poor fitting restorations (fillings and crowns etc) To avoid any bad breathe you need to improve your oral hygiene and see the dentist and hygienist regularly.