The bacteria which cause the disease are normally in the mouth, and continually form on the teeth as a thin film, requiring meticulous personal removal on a daily basis. Periodontal surgery can achieve a complete cleansing of deeply hidden bacterial deposits at a point in time. If the bacteria are kept off of the teeth long enough afterward for reattachment and healing to occur, then a healthy and maintainable periodontal attachment can be achieved, and the teeth can be saved. However, if the bacterial film is allowed to build up during the healing period when the gum is actually less resistant to the destructive effects of bacteria, the result may be less than desired. Many people have undergone periodontal surgery to little avail when bacterial deposits have been allowed to quickly accumulate afterward, and consequently further extensive treatment has been necessary.