What's the connection between oral health and overall health?

Like other areas of the body, your mouth teems with bacteria — mostly harmless. But your mouth is the entry point to your digestive and respiratory tracts, and some of these bacteria can cause disease.

Normally the body's natural defenses and good oral health care, such as daily brushing and flossing, keep bacteria under control. However, without proper oral hygiene, bacteria can reach levels that might lead to oral infections, such as tooth decay and gum disease.

Also, certain medications — such as decongestants, antihistamines, painkillers, diuretics and antidepressants — can reduce saliva flow. Saliva washes away food and neutralizes acids produced by bacteria in the mouth, helping to protect you from microbes that multiply and lead to disease.

Studies suggest that oral bacteria and the inflammation associated with a severe form of gum disease (periodontitis) might play a role in some diseases. And certain diseases, such as diabetes and HIV/AIDS, can lower the body's resistance to infection, making oral health problems more severe.