Enamel is the outer protective coating of a tooth. Over time, the enamel can become discolored through staining. In addition, the dentin, the second layer in teeth, has a yellowish color, which becomes visible as enamel thins over time. Teeth whitening trays, which are sold over the counter and use bleaching agents, are one method used to brighten teeth.
Hydrogen peroxide or carbamide peroxide are typically used to whiten teeth. The United States Food and Drug Administration (FDA) only allows the term "bleaching" to be used when the treatment whitens teeth more than the teeth originally were. "Whitening" can be used to refer to anything that cleans the teeth of debris, including toothpaste. Manufacturers may use the term "whitening" even when the product is actually bleaching the teeth.
People who wish to lighten their teeth can purchase over-the-counter teeth whitening trays. These teeth whitening trays are "one size fits all." Dentists can provide custom-fit teeth whitening trays as well as suggest other treatments to whiten teeth.
Over a lifetime of using teeth to cut and chew food, people cause wear and tear on their teeth enamel. Tooth enamel can develop small cracks, which can hold debris or stains. The teeth are more likely to become stained or discolored.
Genetics plays a role in tooth staining. People are born with a tooth shade of color ranging from yellow-brown to green-gray. As people age, the tooth color with which they were born becomes deeper. Colors that lean towards yellow-brown are typically easier to brighten. In addition to color, people are born with a given thickness of the teeth and translucence, or transparency. The thicker and more opaque, or less transparent, the teeth are, the easier the teeth are to whiten.
Tetracycline is an antibiotic that is used to treat bacterial infections such as acne or urinary tract infections. When pregnant women take tetracycline, the color of their babies' teeth can be affected. These babies may be born with teeth that have brown or gray colors in stripes or ribbons. Women who are pregnant or are thinking about getting pregnant should discuss the risks of taking this drug with their physicians.
What people ingest also can impact the color of their teeth. People who smoke are more likely to have teeth with yellow stains. Drinking colas, coffee, and red wine can stain the teeth. In addition, acidic foods such as citrus fruits can attack tooth enamel, making that dentin color more apparent or allowing more cracks to form.
Some people react to stress by grinding their teeth. Grinding teeth can cause tiny cracks in the enamel. In fact, anything that can cause cracks in enamel, including injuries. This makes staining teeth easier.
Overall, aging can affect how easy it can be to remove stains. It is much easier to remove stains from the teeth of younger people than from the teeth of older people. Stains on adults and older adults can be more stubborn simply because the stains have been building up over time.