Gum disease is a slow, insidious, progressive disease which is often ignored. Initially, there are very minor symptoms, like bleeding when flossing. Eventually, looseness of the teeth with complete loss could occur if left untreated.
When a typical six-month cleaning is not sufficient to remove all of the debris, a more extensive cleaning (or "deep scaling") must be performed. Usually, this is all that is needed to circumvent any further disease process. If the disease has progressed more than at this stage, some type of surgery may be required. The best course of action would be to come in for a routine visit to make sure that everything is in order.