Tooth Discoloration: The Two Types of Tooth Stains
There are two categories of staining as it relates to the teeth: extrinsic staining and intrinsic staining.
Extrinsic stains are those that appear on the surface of the teeth as a result of exposure to dark-colored beverages, foods and tobacco, and routine wear and tear. Superficial extrinsic stains are minor and can be removed with brushing and prophylactic dental cleaning. Stubborn extrinsic stains can be removed with more involved efforts, like teeth bleaching. Persistent extrinsic stains can penetrate into the dentin and become ingrained if they are not dealt with early.
Intrinsic stains are those that form on the interior of teeth. Intrinsic stains result from trauma, aging, exposure to minerals (like tetracycline) during tooth formation and/or excessive ingestion of fluoride. In the past, it was thought that intrinsic stains were too resistant to be corrected by bleaching. Today, cosmetic dentistry experts believe that even deep-set intrinsic stains can be removed with supervised take-home teeth whitening that is maintained over a matter of months or even a year.
What Causes Tooth Staining?
- Age: Over the years, teeth darken as a result of wear and tear and stain accumulation.
- Starting Color: We are all equipped with an inborn tooth color that ranges from yellow-brownish to greenish-grey, and intensifies over time.
- Translucency and Thinness: These are also genetic traits that become more pronounced with age.
- Eating Habits: Acidic foods such as citrus fruits and vinegar contribute to enamel erosion. As a result, the surface becomes more transparent and more of the yellow-colored dentin shows through.Nicotine leaves brownish deposits which slowly soak into the tooth structure and cause intrinsic discoloration.
- Drugs & Chemicals: Tetracycline usage during tooth formation produces dark grey or brown ribbon stains which are very difficult to remove.
- Smoking: Nicotine leaves brownish deposits which slowly soak into the tooth structure and cause intrinsic discoloration.
- Grinding: Most frequently caused by stress, teeth grinding (gnashing, bruxing, etc.) can add to micro-cracking in the teeth and can cause the biting edges to darken.
- Trauma: Falls and other injuries can produce sizable cracks in the teeth, which collect large amounts of stains and debris.