When it comes to mould, we automatically think of that awkward corner in the bathroom or the space under the kitchen sink. But an oral irrigator rarely comes to mind. That's because we don't get into the habit of checking inside the tank and that's something that has to be changed. Oral appliances that use water tend to develop mould in certain areas, so if you want to maintain your teeth in perfect condition, you should also keep your oral health devices free of bacteria and mould.