Taking good care of your mouth, teeth and gums is a worthy goal in and of itself. Good oral and dental hygiene can help prevent bad breath, tooth decay and gum disease—and can help you keep your teeth as you get older.

Researchers are also discovering new reasons to brush and floss. A healthy mouth may help you ward off medical disorders. An unhealthy mouth, especially if you have gum disease, may increase your risk of serious health problems such as heart attack and stroke.

What’s in your mouth reveals much about your health

A look inside or a swab of saliva can tell your doctor volumes about what’s going on inside your body.

Many conditions cause oral signs and symptoms

Your mouth is a window into what’s going on in the rest of your body, often serving as a helpful vantage point for detecting the early signs and symptoms of systemic disease — a disease that affects or pertains to your entire body, not just one of its parts. Systemic conditions such as AIDS or diabetes, for example, often first become apparent as mouth lesions or other oral problems

Protection against harmful invaders: How saliva disables bacteria and viruses

Saliva is also one of your body’s main defenses against disease-causing organisms, such as bacteria and viruses. It contains antibodies that attack viral pathogens, such as the common cold and HIV. And it contains proteins called histatins, which inhibit the growth of a naturally occurring fungus called Candida albicans. When these proteins are weakened by HIV infection or other illness, candida can grow out of control, resulting in a fungal infection called oral thrush.

Saliva also protects you against disease-causing bacteria. It contains enzymes that destroy bacteria in different ways, by degrading bacterial membranes, inhibiting the growth and metabolism of certain bacteria, and disrupting vital bacterial enzyme systems.

The problem with dental plaque: Links to infections and diseases

Though your saliva helps protect you against some invaders, it can’t always do the job. More than 500 species of bacteria thrive in your mouth at any given time. These bacteria constantly form dental plaque — a sticky, colorless film that can cling to your teeth and cause health problems.

Your mouth as infection source

If you don’t brush and floss regularly to keep your teeth clean, plaque can build up along your gum line, creating an environment for additional bacteria to accumulate in the space between your gums and your teeth. This gum infection is known as gingivitis. Left unchecked, gingivitis can lead to a more serious gum infection called periodontitis. The most severe form of gum infection is called acute necrotizing ulcerative gingivitis, also known as trench mouth.

Bacteria from your mouth normally don’t enter your bloodstream. However, invasive dental treatments — sometimes even just routine brushing and flossing if you have gum disease — can provide a port of entry for these microbes. Medications or treatments that reduce saliva flow and antibiotics that disrupt the normal balance of bacteria in your mouth can also compromise your mouth’s normal defences, allowing these bacteria to enter your bloodstream.

If you have a healthy immune system, the presence of oral bacteria in your bloodstream causes no problems. Your immune system quickly dispenses with them, preventing infection. However, if your immune system is weakened, for example, because of a disease or cancer treatment, oral bacteria in your bloodstream (bacteraemia) may cause you to develop an infection in another part of your body. Infective endocarditis, in which oral bacteria enter your bloodstream and stick to the lining of diseased heart valves, is an example of this phenomenon.

Plaque as a cause of common conditions?

Long-term gum infection can eventually result in the loss of your teeth. But the consequences may not end there. Recent research suggests that there may be an association between oral infections — primarily gum infections — and poorly controlled diabetes, cardiovascular disease and preterm birth. More research is needed to determine whether oral infections actually cause these conditions, which include:

• Poorly controlled diabetes. If you have diabetes, you’re already at increased risk of developing gum disease. But chronic gum disease may, in fact, make diabetes more difficult to control, as well. Infection may cause insulin resistance, which disrupts blood sugar control.
• Cardiovascular disease. Oral inflammation due to bacteria (gingivitis) may also play a role in clogged arteries and blood clots. It appears that bacteria in the mouth may cause inflammation throughout the body, including the arteries. This inflammation may serve as a base for the development of atherosclerotic plaques in the arteries, possibly increasing your risk of a heart attack or stroke. Some research suggests that people with gum infections are also at increased risk of heart attack and stroke. The more severe the infection, the greater the risk appears to be. And gum disease and tooth loss may contribute to plaques in the carotid artery. In one study, 46 percent of participants who’d lost up to nine teeth had carotid artery plaque; among those who’d lost 10 or more teeth, 60 percent of them had such plaque.
• Preterm birth. Severe gum disease may increase the risk of preterm delivery and giving birth to a low birth weight baby. The National Institute of Dental and Craniofacial Research, in fact, estimates that as many as 18 percents of preterm, low birth weight babies born in the United States each year may be attributed to oral infections. The theory is that oral bacteria release toxins, which reach the placenta through the mother’s bloodstream and interfere with the growth and development of the fetus. At the same time, the oral infection causes the mother to produce labor-triggering substances too quickly, potentially triggering premature labor and birth.