WHITER WHITES
Teeth are not white. They are all have a hue of orange, yellow, brown, black or gray. All teeth respond differently to a whitening procedure because of the (hue) color, and intensity of color (Chroma) of the tooth. However, all natural teeeth will respond to a whitening procedure.
How much they will respond and how fats will be a result of total color structure and the percentage of hydrogen peroxide used in the treatement.
It is first important to understand the whitening process at the chemistry level. Molecules of color occur in RING structures with double carbon bonds (C=C) bonds in various locations. Whitening occurs by the oxygen molecule reducing the number of double carbon bonds of color through an oxidation process. Tetracycline stain occurs when the patient is given the Tetracycline antibiotic while the enamel and dentin (outer and inner layers) of teeth are forming. The dye from tetracycline is incorporated into the structure of the tooth, causing a banding pattern of various dark colors. Tetracycline bands can be various shades of yellow, orange, brown, gray or black. Also, dark colored teeth can be a result of rare medical conditions during tooth development. Whenever a dye, or pigment is part of the tooth structure it is called an INTRINSIC STAIN. Yet even Tetracycline stained teeth will whiten. But you must be extremely patient. It could takes months of applying whitening gel to your teeth before you see dramatic results.
Dark gray and brown teeth have increased numbers of double carbon bonds and in harder to reach locations. These colors may require extended treatment time to get a patient's desired results.
There are many factors that can affect the color of a tooth when it is developing. It can range from the child having a fever to the amount of fluoride in the water supply to a type of medication given. Some factors are developmental and not dependent upon the child's exposure. One the most common abnormal tooth patterns is a dark banding known as tetracycline stain. Another abnormal tooth color pattern is the darkening of a tooth by blood pigments trapped in a tooth after it is traumatized in an accident -- typically a hit or fall injury.