Why do teeth change color even when you brush them?
Brushing helps keep surface stains from building up, but it can't reach color that comes from inside the tooth. Teeth change color from two directions.
From the outside, pigments in coffee, tea, red wine and tobacco cling to enamel. From the inside, enamel thins with age so the yellower dentin beneath shows through, and injury, some medications and some conditions change the tooth's own color.
Surface stains or internal discoloration?
| Surface (extrinsic) stains | Internal (intrinsic) discoloration | |
|---|---|---|
| Where it sits | On the enamel surface | Within the enamel or the dentin beneath |
| Common causes | Coffee, tea, red wine, cola, tobacco | Aging, injury, childhood tetracycline or doxycycline, fluorosis, decay, old silver fillings, a tooth whose nerve has died |
| Medications | Not usually | Some antihistamines, antipsychotics and blood pressure medicines; chemotherapy and head and neck radiation |
| What can help | Professional cleaning, stain-removal toothpaste, whitening | Whitening helps some cases; gray may not respond; a single dark tooth may need internal whitening; bonding or veneers when whitening can't reach |
Sources: ADA Whitening and ADA MouthHealthy.
One detail surprises people: nicotine is colorless until it mixes with oxygen, then it turns yellowish and stains (ADA).
When a color change is worth a visit
- One tooth is darker than its neighbors. After an injury a tooth can lay down extra, darker dentin, or its nerve may have died. Have it checked before whitening.
- A new brown or dark spot. Decay is one cause of internal discoloration.
- Discoloration with pain or swelling. Call the studio rather than waiting.
- A medication you think is to blame. Don't stop it on your own; ask the prescriber and mention it at your dental visit.
Next step: Request a consultation or call (805) 565-5111. An exam can tell surface stain from internal discoloration and match the treatment to it.
What you can do
- Cut back on tobacco and frequent coffee, tea or red wine.
- Keep up regular professional cleanings to remove surface stain.
- Choose a stain-removal toothpaste with the ADA Seal. It removes surface stain but won't change the tooth's underlying color.
- Talk to a dentist before whitening, especially for gray or single-tooth discoloration (ADA).
Guides are general education; an examination is needed for individual advice.
Prepared with AI assistance and reviewed for clinical accuracy by Dr. Mahmood Loul, DDS on October 19, 2026.
Sources
- Clinician-confirmed statement — Loul Dental Studio
- Oral Health Topics: Whitening and MouthHealthy: Teeth Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- Oral Health Topics: Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- MouthHealthy: Teeth Whitening — American Dental Association
- Clinician-confirmed statement — Loul Dental Studio
- Clinician-confirmed statement — Loul Dental Studio
- Loul Dental Studio: Teeth Whitening — Loul Dental Studio
Sources were current when this guide was last updated.
Educational content, not a diagnosis. Please contact the studio to discuss your own situation.