Gum disease starts when plaque, a sticky film of bacteria, infects your gums. Sugars, starch, and other foods mix with the bacteria in the mouth, and bacteria that are not removed from brushing or flossing can form plaque that later buildups to cause periodontal disease.
If you leave the plague untreated, it will continue to grow and spread. Periodontal disease develops beneath the gums, separating the teeth from the gum by creating small pockets.