Periodontitis, or gum disease, is the infection of the gum tissue that supports the teeth. It is most common reason for tooth loss in adults. It is characterized by swollen, bleeding gums that pull away from the teeth.
Periodontitis is caused by plaque, the sticky film that covers teeth. If plaque is not removed, it hardens and becomes tartar. The tartar builds up on the teeth and irritates the gums, causing periodontitis.
There are several stages of periodontitis. The first (and least severe) stage is known as gingivitis. During this stage, gums are red and swollen but have not started to pull away from the teeth. Gingivitis can usually be reversed by meticulous brushing and flossing.
The other stages of periodontitis are distinguished as mild, moderate, or severe. If periodontitis is not treated it can cause irreversible bone and ligament loss.