Bad breath is usually associated with bacteria in the mouth that produce sulphur containing compounds such as hydrogen sulfides and methyl mercapatans. These compounds not only smell bad, but they also are damaging to the oral tissues. Professional cleaning along with home plaque control gives the best results. Bad breath that returns very shortly after a cleaning indicates that there may be some deep-seated problems that may have been overlooked. Bad breath is occasionally seen with medical conditions such as kidney failure and diabetes.