A dental examination is important for detecting the cause of your symptoms. It is possible that there could be an abscess or retention of debris under
. A loose crown can lead to lodgement of bacteria under it and cause bad odour.Other causes of bad breath from mouth are tooth decay, sinus disease or gum diseases or reflux disease. Tonsilloliths can also cause bad breath, sore throat, white debris, difficulty in swallowing and tonsillar swelling .These are only possibilities.