Dental (Oral) Health Quiz: Test Your Dental Hygiene IQ

Tooth decay occurs when foods containing carbohydrates (sugars and starches) are left on the teeth. Bacteria that live in the mouth digest these foods, turning them into acids. The bacteria, acid, food debris, and saliva combine to form plaque, which clings to the teeth. The acids in plaque dissolve the enamel surface of the teeth, creating holes in the teeth called cavities, or dental caries.

It is generally recommended that an infant be seen by a dentist by 1 year of age or within 6 months after the first tooth comes in.

Bad breath, medically called halitosis, can result from poor dental hygiene and may be a sign of other health problems. Bad breath can also be made worse by the types of foods you eat and other unhealthy lifestyle habits.

Gum disease can be prevented by removing plaque. Plaque removal can be easily accomplished by thoroughly brushing and flossing your teeth daily. Regular dental check-ups (every 6-12 months) can detect early signs of gum disease.

Some studies have linked common oral problems to illnesses, including heart disease, stroke, diabetes, premature birth, osteoporosis, and even Alzheimer's disease. In most cases, the strength and exact nature of the link is unclear, but researchers suggest that dental health is important for preserving overall health.

"Although tooth loss is common, it's not an inevitable part of aging," says Richard H. Price, DDS, a retired dentist in Newton, Mass., and spokesman for the American Dental Association. "Teeth do not die a natural death -- we kill them. Exactly how do we do that? In short, by disease or trauma," he says.

The name -- black hairy tongue -- may sound scary, but the condition is actually harmless. Black hairy tongue is caused by bacteria or fungi in the mouth, which make the tongue appear black and hairy. It's easily remedied by good old-fashioned oral hygiene.

Oral cancer presents as a mouth sore that doesn't go away and can be accompanied by unexplained numbness in the face, mouth, or neck. There may be problems chewing, speaking, or swallowing. Don't let fear keep you from the doctor -- oral cancer that is caught early is treatable and curable.

The American Dental Association recommends throwing out your toothbrush every three to four months. If the bristles become frayed, you're sick, or you have a weak immune system, throw it out even more often. If you use an electric toothbrush, throw out the head as often as you'd discard a disposable toothbrush.

Gingivitis (gum inflammation) usually precedes periodontitis (gum disease). In the early stage of gingivitis, bacteria in plaque buildup causes the gums to become inflamed (red and swollen) and often easily bleed during tooth brushing. Although the gums may be irritated, the teeth are still firmly planted in their sockets. No irreversible bone or other tissue damage has occurred at this stage.