Gum disease occurs in two progressive stages – gingivitis and then periodontitis. As plaque slowly accumulates on the teeth and below the gum line, gingivitis develops. At this stage, no irrevocable damage will have occurred. However, plaque below the gum line does affect the gum tissue, teeth, and bone by slowly breaking each of them down. As the gums pull back from the teeth, pockets appear which invite infection. The bone deteriorates, weakening the foundation for the tooth. With weakened bone and gum, the teeth become more prone to falling out. This is the periodontitis stage of gum disease.