No teeth are perfectly white. But discolored teeth can be lightened to reach a natural tooth shade.
Contrary to many advertisements, it is difficult to obtain perfectly white teeth. Natural, healthy teeth have extremely subtle yellow, brown or gray tones. Shine a flashlight behind your front teeth and look in the mirror to see for yourself. Pure white teeth are like purple hair — they appear synthetic and distracting! However, light tooth shades are extremely attractive. What marketers refer to as “teeth whitening” should more accurately be called “teeth lightening.”
Tooth shade varies between people and even between teeth from the same person. Generally, permanent teeth are darker than primary teeth, and they have a yellow or gray tint to them. This coloration depends upon the natural shade of the outer layer of tooth structure (enamel) and the tooth layer under the enamel (dentin). It also depends upon the thickness and translucency of the enamel. Dentin can be very yellow. If the enamel layer is thin or very translucent, the yellow dentin will show through the enamel. These factors help explain why some teeth respond better to bleaching treatments than others. Professional bleaching by your dentist will help assure a matched, even tooth shade across your smile.
Stains change tooth structure, which make teeth less transparent. Teeth can become discolored during their formation or after they have erupted. Some medications, especially tetracycline, discolor teeth. If too much fluoride is ingested during tooth development, the teeth can become mottled. This condition is called fluorosis. Discoloration that occurs during tooth development is known as intrinsic staining. Staining or discoloration which occurs after the tooth has erupted is called extrinsic staining. Coffee, tea, tobacco and red wine quickly cause extrinsic stains. Intrinsic stains are much more difficult to lighten than extrinsic stains.
Remember, all human teeth show slight and varying tones of yellow, brown or gray. If you are unhappy with the current shade of your teeth, modern dentistry offers you the option of professional bleaching, veneers and other restorative techniques to lighten your natural tooth shade.