The tartar is a hardened plaque due to the buildup of minerals from saliva. The plaque itself is a thin, sticky and colorless layer, which forms continuously on the teeth. There are bacteria in the plaque that produce acid which causes cavities and inflammation of the gums. If the plaque is not cleaned regularly, the plaque will harden and is called tartar. The tartar cannot be cleaned only by brushing your teeth, but it must be cleaned by a dentist with a special tool called a scaler. The process of cleaning tartar is known as scaling.