If you value a sparkling white smile as part of your personal appearance, you likely do everything you can to avoid common stains from red wine, cigarettes, and other sources of daily discoloration. However, sometimes no amount of special care for your teeth can completely prevent discoloration, especially when a single tooth begins turning gray. Find out why you’re experiencing a gray coloration so you can make a decision about what to do about it to restore your smile.

Tetracycline Antibiotics

Tetracycline is a powerful antibiotic that was widely prescribed for both serious and routine infections, such as sinus infections. Unfortunately, many people who took this medication as a child only discovered that it could cause gray discoloration from the inside out once they became adults. The related antibiotics doxycycline and minocycline also have a chance to create this kind of color change in the teeth.

In fact, your stains may even be linked to antibiotics taken by your mother while you were in the womb. Color may change in only a single tooth or multiple teeth, while the gray color can lean towards yellow or brown as well. A dentist can determine if your stains are linked to antibiotics with a simple UV light since residue from these medications will glow under a black light. It’s tricky to treat internal staining, but it is possible.

Other Medications

In most cases, medicine-induced gray tooth discoloration is tied to certain antibiotics. However, there are many other medications that stain teeth, and there’s always a chance the stain will appear gray rather than yellow, brown, or off-white. These medications include:

  • Mouth rinses with chlorhexidine
  • Antihistamines used to treat allergies, such as Benadryl
  • Some medications designed for treating hypertension
  • Many antipsychotic drugs.

Of course, most of these medications are important enough that it’s worth the risk of some tooth discoloration that doesn’t affect the overall strength of each tooth. It’s better to treat the discoloration if it occurs than to avoid using a necessary medication out of fear of a gray stain. Not everyone experiences a chance in tooth color after taking these medicines either. It’s unclear why some people have discoloration while others don’t, but it may be linked to genetic susceptibility to certain drug compounds or the total dosage and length of treatment.

Injury or Trauma

When gray tooth color is isolated to just a single molar or bicuspid, it’s often due to an injury or trauma that left the interior of the tooth partially or completely dying out. As the tissue inside dies and decomposes, the gray color appears from the inside out. However, this tissue damage does not necessarily spread after the tooth heals and stabilizes. Unless the color continues to darken or you experience other symptoms like pain and a loose socket, you can safely continue life as usual after an injury causes a tooth to turn gray.

Compromised Dental Work

Any filling, crown, root canal, or other major dental work that becomes compromised by bacteria or physical damage can cause the surrounding tooth to turn gray as time passes. Unlike gray coloration created by a sudden blow to the tooth or other traumatic injury, gray tints caused by ruined dental work indicate a serious issue that needs attention as soon as possible. Ignoring a color change in a tooth that had a root canal or which is fitted with a crown could cause you to lose the tooth and potentially damage the surrounding teeth. By having the filling or crown inspected and repaired by a cosmetic dentist as soon as you notice a color change, you’re preventing more serious damage from spreading to the rest of the mouth.