The Deal

• $64.80 for dental exam, x-rays, and basic cleaning ($318 value)

Enamel: The First Line of Dental Defense

Dentists help you maintain one of your body’s most precious assets, enamel. Check out Groupon’s guide to the substance sworn to protect your teeth for life.

Stronger than nail, bone, or even a heart of stone, tooth enamel is the strongest tissue in the human body. Like a suit of armor, enamel shields the teeth from bacteria and insulates their sensitive nerves against the extreme temperatures of tea or ice cream. However, that strength comes at a price: unlike almost anything else in the body, enamel isn’t made of living material. Rather, it’s a collection of tightly bound, mineralized proteins, and although it can be nurtured by a substance like fluoride, it can’t truly regenerate. (In fact, the mineral that forms enamel, calcium phosphate, is found in another precious commodity: pearls.) For all its strength, enamel can slowly deteriorate if not cared for, leaving the underlying material, known as dentin, virtually defenseless.

Enamel has many enemies, chief among them acid. Along with food already high in acid—such as soda or carbonated lemons—sugars and starches can also cause decay; bacteria in the mouth metabolize the carbohydrates to produce new acid, eating away at the enamel as they feed. Besides corrosion, other causes of enamel decay range from tooth grinding to a lack of enamel’s most important ally: saliva. Rich in protective calcium and other minerals, saliva helps dilute acid and flush food from the mouth. Another trusted bodyguard, fluoride, can also help prevent tooth decay by accelerating the growth of enamel crystals, strengthening the mineral and making it more resistant to attack.