The tongue's rough and porous surface is the perfect playground for plaque-causing bacteria in our mouths. If the tongue isn't cleaned regularly and continues to harbour these bacteria, it can serve as a reservoir and continuously re-seed the teeth and gums. Not only do the bacteria coating the tongue contribute to plaque formation, they also can produce a nasty odour, resulting in bad breath.The solution is brushing your tongue with a soft-bristled toothbrush, at least a couple of times a week. An alternative is to use a tongue scraper, which is a hand-held device drawn across the surface of the tongue to remove bacteria. Tongue scrapers are ok, but they're really no better than a good toothbrush.It's up to you; the important thing is that you do it on a regular basis!