I have constant bad breath especially in morning after wokeup... recently my auditory nerve had loss of 25db hearing loss.... I searched in Google and the matter it came was this..is it my reason... can my hearing  restored These bacteria  in mouth can enter your blood steam and cause infection and inflammation. If the inflammation narrows your arteries and blood vessels, it can lead to hearing loss. One factor in the death of the hair cells in the ear that are so vital to good hearing is ample blood circulation. Reduce the blood flow to those tiny blood vessels in the inner ear and the hair cells die, never to be replaced. If the bacteria lead to inflammation in the vessels in the brain, dementia may not be the only result. The portion of the brain that processes signals from the auditory nerve also relies on blood circulating through tiny vessels.