What causes chronic periodontitis?

Chronic periodontitis occurs when inflammation or infection of the gums (gingivitis) is untreated or treatment is delayed. Infection and inflammation spreads from the gums (gingiva) to the ligaments and bone that support the teeth. Loss of support causes the teeth to become loose and eventually fall out. Periodontitis is the primary cause of tooth loss in adults. Periodontitis is uncommon in childhood but increases during adolescence.

The following can contribute to chronic periodontitis:

• smoking or tobacco use
• puberty, pregnancy, and menopause in women 
• stress
• medications
• clenching or grinding your teeth
• poor nutrition and obesity
• diabetes and any other disease that interferes with the body's immune system

If left untreated, gingivitis often progresses into periodontitis, as plaque grows in pockets under the gum and cultivates the growth of toxic bacteria. Your immune system attacks the bacteria and triggers this autoimmune disorder. The toxins produced by the bacteria cause inflammation in the tissues surrounding the teeth, destroying the tissues and bones by the body's own immune response.

A virus may also trigger the onset or worsening of chronic periodontitis by releasing tissue-damaging proteins, encouraging the growth of bacteria, and suppressing immune factors.