When plaque is not removed properly, it attracts bacteria and turns into difficult to remove calculus, or tartar. The bacteria spreads to the gums and causes them to pull away from the tooth, creating periodontal pockets. When the periodontal disease is left untreated, it can spread to the bone and cause tooth loss. Scaling and root planing can be effective in the early stage of gum disease, called gingivitis. Many patients who have gingivitis or more advanced stages of periodontal disease often experience bleeding and sore gums when brushing, flossing and eating.