Teeth staining and darkening is an unavoidable fact of life. From the time we get our permanent teeth, foods and aging cause our teeth to yellow and lose their whiteness. Teeth whitening can brighten the teeth by removing stains, but all tooth stains and discolorations are not alike, and some are more difficult to remove than others. Intrinsic tooth discoloration is stains or dark colors that are on the inner layer of the tooth.
Teeth whitening procedures are effective at removing stains that are caused by food and beverages like coffee or wine, and stains that are caused by smoking. Our teeth get darker naturally as we get older, and older patients can often get good results from teeth whitening too. The most problematic stains are the ones that are caused by internal factors and stain the teeth’s inner layer, the dentin, because these do not respond well to whitening products. The exterior layer of our teeth, the enamel, is translucent, which means that light passes through it. The dentin and any stains on it can be seen through the enamel and appear to be on the surface. Removing stains that are actually on the enamel, like food stains, is easy with bleaching products, but these products cannot get through to the dentin to remove intrinsic stains. When you have intrinsic discoloration or stains, whitening your teeth may require bonding or veneers to replace or conceal the discolored portion of the teeth.
Intrinsic tooth discoloration is often caused by things that may have happened to you as a child or even before you were born. Some causes of intrinsic tooth discoloration include excessive exposure to fluoride in childhood, taking antibiotics before you were about 8 years old and antibiotic use by your mother when she was pregnant. Intrinsic discoloration can also be called by trauma or injury to the tooth, especially if there was internal bleeding.
If you have stubborn stains or dark spots on your teeth that do not improve with teeth whitening procedures, they may be intrinsic. You can discuss whitening options with the dentist. Sometimes a combination of teeth whitening and cosmetic procedures like veneers or bonding can result in a completely white and beautiful smile.