What influences the shade of teeth?

The teeth of humans, as a race, display a wide range of different shades of white. There is no one specific color that a person's teeth are supposed to be or should be. Some people's teeth are just naturally lighter in color than others.  It seems to be a fact of life that as years pass a person's teeth will have a tendency to stain and discolor. The degree to which a person's teeth will darken can often be correlated somewhat to the amount of exposure they have had to "chromogenic agents" such as tea, coffee, colas, red wine, and tobacco products. Some tooth staining is a result of a person's systemic exposure to certain types of medicines. One known culprit is the antibiotic tetracycline (and also the related compounds minocycline and doxycycline). If children are given tetracycline during those years when their tooth enamel is forming their teeth can acquire a yellow-brown to blue-grey staining. For this reason tetracycline (and related antibiotics) are seldom prescribed for children eight years and younger or for pregnant women. The use of the minocycline, even by adults, has been reported to cause grey tooth staining.  If children ingest an excessive amount of fluoride during that time period when their teeth are developing a type of tooth staining termed "fluorosis" can result. The most common form of fluorosis has the appearance of chalky-white patches or lines across the surface of a tooth. In more severe cases fluorosis can take the form of brown tooth staining or even a pitting of a tooth's surface. (Parents should be aware that a common source of fluoride ingestion is when children swallow toothpaste. It has been suggested that children under the age of five swallow essentially all of the toothpaste that has been placed on their brush.)

There are times when a single tooth has experienced certain types of changes or events and as a result has become darker than its neighboring teeth. As an example, it is commonplace that a tooth that has had root canal treatment will darken over time. Another common example is a tooth that has a history of having been traumatized, such as having been bumped in an accident. In this latter case the darkening can be indicative of a problem associated with the health of the nerve found inside the tooth. Any individually darkened tooth should always be evaluated by a dentist.