According to this article from about.com, there are many good reasons to get your teeth cleaned. The most important one mentioned, in my opinion, is to prevent gum disease. Many people have gum disease but don’t even know it because gum disease is often painless. Gum disease is caused by the bacteria in our mouth. When that bacteria eats left over food, its by product is plaque. Plaque is that white film you can scratch off your tooth with your finger nail. If you have plaque, it is important to clean that stuff off by brushing and flossing. If you leave plaque alone, over time it will become tartar, also known as calculus. Tartar is basically calcified plaque. Once tartar forms it is nearly impossible to get it off at home. Don’t try to remove it at home. By getting your teeth cleaned at least every 6 months, it will help prevent you from getting gum disease.