Periodontitis is an elevated form of gingivitis. This stage is often characterized by an increase in swelling and irritated gums when brushing and flossing. You may also notice your gums beginning to detach from the surfaces of your teeth and receding toward the roots. Periodontal pockets will also form and trap bacteria. At this point, the supporting bone and tissue structures can become damaged and immediate treatment will be necessary to prevent further bone or tooth loss.