Gum disease:

Gingivitis is an inflammation of the gums, usually caused by a bacterial infection. If left untreated, it can become a more serious infection known as Periodontitis. Gingivitis and periodontitis are major causes of tooth loss in adults.

What causes gingivitis and periodontitis?

Plaque is a thin film of bacteria. It constantly forms on the surface of your teeth. As plaque advances, it hardens and becomes tartar. You can develop an infection when plaque extends below the gum line. Left untreated, gingivitis can cause the gums to separate from the teeth. This can cause damage to the soft tissue and bone supporting the teeth. The tooth may become loose and unstable. If the infection progresses, you may ultimately lose your tooth or need a dentist to remove it.