Why do teeth stain?
Teeth change color in two different ways, and the difference decides what helps. The ADA splits tooth discoloration into two kinds:
| Surface stains (extrinsic) | Inside the tooth (intrinsic) | |
|---|---|---|
| Where | Colored compounds build up on the enamel | Within the enamel or the dentin under it |
| Common causes | Coffee, tea, red wine, cola, tobacco, plaque | Aging, too much fluoride or certain antibiotics while teeth form, an injury |
| What helps | Cleaning, a stain-removal toothpaste, cutting back | Peroxide whitening for some; bonding or veneers for others |
Many people have both. Cleveland Clinic notes that professional whitening works best on surface stains.
Coffee, tea, red wine and cola
Dark drinks are the classic surface stainers. MouthHealthy calls coffee, tea and red wine "major staining culprits", and the ADA adds cola drinks. How often you drink them matters, which is why the quiz asks how many a day or week.
We didn't find a reliable source that ranks coffee against tea, so the quiz scores them the same. If you love your coffee, simple habits help. Cleveland Clinic suggests drinking water and rinsing after staining drinks, and limiting cola, tea, coffee and red wine.
Tobacco
Smoking and chewing tobacco cause some of the most stubborn stains. MouthHealthy says two chemicals in tobacco, tar and nicotine, create them. Cleveland Clinic says brown stains are usually linked with smoking or chewing tobacco. That's why tobacco counts for 3 points in the quiz, the most of any single answer.
Plaque holds stain
Stains cling to plaque, says Cleveland Clinic, so skipping brushing and flossing raises the risk. Brush for 2 minutes twice a day, clean between your teeth daily, and keep up routine dental cleanings. The ADA notes that brushing with a whitening toothpaste or a professional cleaning can reduce a wide range of surface stains. The Two-Minute Brushing Timer helps you hit the full 2 minutes.
Chlorhexidine mouthwash
Chlorhexidine is a prescription mouth rinse. MedlinePlus warns it may stain teeth, the tongue and fillings, and may permanently stain front-tooth fillings. Its advice: brush and floss daily, especially discolored areas, and see your dentist to remove stain and tartar. The ADA classes staining from long-term chlorhexidine use as intrinsic. Don't stop a prescribed rinse on your own: ask your dentist.
Color changes inside the tooth
- Aging. With age, enamel thins and more of the yellowish dentin shows through (MouthHealthy). The ADA calls aging a common cause of intrinsic discoloration.
- Tetracycline. MedlinePlus says tetracycline used during pregnancy or in children under 8 can permanently stain teeth. The ADA lists antibiotic use in childhood as an intrinsic cause.
- Fluorosis. Faint white lines, streaks or flecks from too much fluoride while teeth form. The chance exists until about age 8 (MouthHealthy). The CDC says it's mostly mild and cosmetic in the US, doesn't affect how teeth work, and adults can't develop it. For safe amounts of toothpaste for kids, see the Kids Fluoride Calculator.
- Medicines. MouthHealthy says tooth darkening can be a side effect of certain antihistamines, antipsychotics and high blood pressure medicines.
- Injury. A tooth can change color after a knock, as it reacts by laying down more dentin (MouthHealthy).
How to prevent stains
- Drink water and rinse after coffee, tea, red wine or cola (Cleveland Clinic).
- Brush twice a day for 2 minutes and floss daily.
- Keep up routine dental cleanings.
- Quit tobacco.
- After acidic food or drinks like citrus or soda, wait about an hour before brushing (Cleveland Clinic).
Whitening options compared
The ADA describes four main routes. None is "best" for everyone:
| Option | How it works | Good to know |
|---|---|---|
| Whitening toothpaste | Abrasives remove surface stains | Doesn't change the tooth's own color. Look for the ADA Seal for stain removal |
| Over-the-counter strips and gels | Peroxide at lower strength than dentist products | Some carry the ADA Seal, meaning they were tested for safety and effectiveness when used as directed |
| Take-home trays from a dentist | Custom trays, typically 10% to 38% carbamide peroxide | Not eligible for the ADA Seal; your dentist supervises |
| In-office whitening | Stronger peroxide gel, with or without a light | Done by your dentist |
Sensitivity and gum irritation are the most common side effects. The ADA says mild to moderate sensitivity can affect up to two-thirds of users early in treatment, and it's usually short-lived. Gum irritation can also happen, often from gel touching the gums, and it usually settles after treatment. If your teeth are already sensitive, try the Tooth Sensitivity Quiz first.
Fillings and crowns don't whiten. The ADA says only natural teeth whiten, not tooth-colored restorations such as crowns. MouthHealthy adds that whitening won't work on caps, veneers, crowns or fillings, or on discoloration caused by medicines or an injury.
Ask your dentist first. The ADA's policy supports talking with a dentist to decide whether whitening suits you. Whitening toothpastes rely on abrasives, so if you have exposed roots, check yours in the Toothpaste RDA Chart.
How this tool works
The score. Each habit answer has points, and your score is the total. The points are our own simple tally, not a validated clinical score:
| Habit | Points |
|---|---|
| Coffee or tea | 1 a day = 1; 2 or more a day = 2 (each) |
| Red wine or cola | Most weeks = 1; most days = 2 (each) |
| Tobacco | 3 |
| Chlorhexidine rinse for weeks or longer | 2 |
| Brushing | Once a day = 1; less = 2 |
| Cleaning between teeth | Sometimes = 1; rarely = 2 |
| No dental cleaning in the past year | 1 |
The maximum is 18. Bands are our own convention: Low 0–2, Moderate 3–5, Higher 6–8, High 9 or more. Each band is a quarter of the meter.
Inside-the-tooth answers don't add points. Aging, tetracycline, fluorosis, medicines and dental work change the explanation and the whitening notes instead. Dentist flags (one dark tooth, dark spots or stains with pain) override everything with a "see a dentist" message.
Limits: the quiz can't see your teeth or measure their shade. It shows how many habits commonly linked with staining apply to you, not a diagnosis.
Frequently asked questions
What causes stains on teeth?
Does coffee or tea stain teeth more?
Is teeth whitening safe?
Why is one of my teeth turning gray?
What are the white spots on my teeth?
Does chlorhexidine mouthwash stain teeth?
Sources
- American Dental Association. Whitening (Oral Health Topics). updated August 16, 2022. Extrinsic and intrinsic causes, whitening options, the ADA Seal, side effects and the ADA's policy that people should consult a dentist before whitening. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Teeth Whitening. Accessed October 26, 2026.
- Cleveland Clinic. Tooth Discoloration: Causes & Treatment. updated July 3, 2025. Accessed October 26, 2026.
- Centers for Disease Control and Prevention (CDC). About Dental Fluorosis. May 15, 2024. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Fluorosis. Accessed October 26, 2026.
- MedlinePlus (U.S. National Library of Medicine). Tetracycline: MedlinePlus Drug Information. revised June 15, 2026. Accessed October 26, 2026.
- MedlinePlus (U.S. National Library of Medicine). Chlorhexidine mouth rinse: MedlinePlus Drug Information. revised June 15, 2025. Accessed October 26, 2026.
- American Dental Association. Toothpastes (Oral Health Topics). updated February 11, 2026. Accessed October 26, 2026.
- American Dental Association (MouthHealthy). Brushing Your Teeth. Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.