The early stage of periodontal disease is called gingivitis. Bacteria produce toxins that cause gum irritation. Tartar forms a rough surface attracting more plaque. The gums may become red, swollen, and bleed. Pockets may develop between the gum and tooth. The gums may be sore but in many cases there is no discomfort. It is still a dangerous situation because if not treated, the disease can cause damage to the bone surrounding the teeth. It may eventually progress to periodontitis. Gingivitis can be reversed.
Periodontitis is a more advanced stage of periodontal disease. Gingivitis has spread into the bone. Plaque and tartar continue to accumulate which results in loss of bone and the supporting structures of the teeth. Shallow pockets become deep pockets. As these pockets become deeper, they hold more and more bacteria and speed up the rate of tissue damage. Gums pull away from the teeth and recede because of ligament damage.
As the disease progresses, pockets deepen and may fill with pus. Teeth may become loose as bone loss increases. The teeth may eventually fall out or require extraction to preserve the health of your mouth.