Periodontal disease or gum disease is a very common condition where the gum becomes swollen, sore, or infected. The main cause of periodontal disease is plaque, a sticky substance that contains bacteria, which forms in the process of eating and drinking. There are millions of bacteria exposed to our teeth every second. Some bacteria in plaque are harmless, but some are very harmful to the health of your gum. If you have gum disease, your gums may bleed while brushing your teeth and may cause bad breath. This stage of gum disease is known as gingivitis. If gingivitis is not treated in time, a condition called periodontitis can develop. This affects the tissues that support teeth and hold them in place. Untreated periodontitis causes the bone in your jaw to decay and small spaces to open up between the gum and teeth eventually causing the teeth to fall out.