A black spot on a tooth may be a surface stain, hardened tartar, an old restoration or tooth decay. Colour alone cannot confirm the cause, and a painless mark can still need treatment. A dental examination is the safest way to distinguish harmless discolouration from a cavity or crack.
Reviewed by Dr. Manish Pandey, BDS. This article is educational and cannot diagnose a tooth from a photograph.
When is a black spot urgent?
Arrange prompt dental care if the spot is accompanied by toothache, pain on biting, increasing sensitivity, a visible hole, a broken tooth, swelling, pus, a bad taste or fever. Facial swelling with difficulty breathing or swallowing, swelling near the eye or rapidly worsening illness requires emergency medical help.
Common causes of a black spot on a tooth
1. Tooth decay or a cavity
Decay begins when plaque bacteria use sugars and starches to produce acids that remove minerals from enamel. Early decay may appear white rather than black. As damage advances, an area can become brown or black and may eventually form a hole. The NHS lists white, brown or black spots among possible signs of tooth decay.
Decay can be painless at first. Later symptoms may include sensitivity to sweet, cold or hot food, food trapping or toothache. Learn how cavities develop in our detailed tooth-decay guide.
2. Surface staining
Pigments from tea, coffee, tobacco and some foods can collect in enamel grooves or around rough surfaces. Stain is often flat and hard, and several teeth may be affected. A dentist or hygienist can determine whether professional cleaning will remove it. Do not scrape a dark mark with a pin or metal instrument because this can injure the gum or tooth.
3. Stained pits and fissures
Back teeth naturally have narrow pits and grooves. These may take up stain without being actively decayed, but they are also locations where cavities commonly start. A dark fissure therefore cannot be classified reliably by colour alone. The clinician considers texture, cleaning access, symptoms, changes over time and, when appropriate, X-rays.
4. Tartar near the gumline
Plaque that is not removed can mineralise into calculus, commonly called tartar. It may look yellow, brown or dark, particularly where tobacco or other pigments are present. Tartar feels hard and cannot be brushed away safely at home. Professional scaling is used to remove it while the gums are assessed for gingivitis or periodontitis.
5. An old filling or decay around a restoration
Metal restorations can appear grey or black, and the surrounding tooth may look darker. A margin can also stain without necessarily being decayed. However, plaque can collect beside a chipped, leaking or poorly fitting restoration, allowing recurrent decay to develop. An examination and sometimes a dental X-ray help distinguish these possibilities.
A crack can trap pigments and look like a fine dark line. After trauma, bleeding or loss of vitality inside a tooth can make much of the crown turn grey or dark rather than creating a small surface dot. Pain when biting, temperature sensitivity, a previous impact or progressive colour change should be evaluated.
7. Food or debris
A seed husk or other debris can lodge in a groove or between teeth and mimic a spot. Gentle brushing and interdental cleaning may remove it. Do not force sharp objects between teeth. A mark that remains after normal cleaning deserves a dental check rather than repeated picking.
Can you tell whether it is a cavity at home?
No single home sign is definitive. Features that make decay more concerning include a mark that is enlarging, a surface that has become visibly cavitated, food repeatedly catching, sensitivity or pain. But cavities between teeth may be invisible, and some dark grooves are stable stains. Dentists use visual and tactile assessment, drying, history and selective radiographs rather than colour alone.
| Observation | Possible explanation | What to do |
|---|---|---|
| Flat mark on several teeth | Surface stain | Book routine cleaning or examination |
| Dark pit with a visible hole | Possible cavity | Arrange a dental examination |
| Hard dark deposit at gumline | Possible tartar | Professional scaling may be needed |
| Fine dark line with biting pain | Possible crack | Seek prompt assessment |
| Dark tooth after an injury | Possible pulpal damage | Book a dental evaluation |
How a dentist may treat it
Treatment depends on the diagnosis, not the shade of the mark. A superficial stain may only need monitoring or professional polishing. Tartar requires scaling. Very early non-cavitated decay may sometimes be arrested or reversed with fluoride and risk-factor control. Once a hole has formed, a filling is commonly needed. Deeper decay may require root canal treatment or extraction, while a cracked tooth may need bonding, a crown or another tailored approach.
Do not try to bleach, drill, scrape or cover the spot at home. Whitening products cannot repair decay and may make surrounding enamel lighter while the dark area remains.
What to do while waiting for an appointment
- Brush gently twice daily with fluoride toothpaste.
- Clean between teeth once a day with floss or an appropriately sized interdental cleaner.
- Limit frequent sugary snacks and drinks.
- Avoid biting hard food on a painful or cracked tooth.
- Do not place aspirin, chemicals or sharp objects on the tooth.
- Record when you first noticed the mark and whether it is changing.
Our step-by-step brushing guide explains how to clean every tooth surface without aggressive scrubbing.
How to lower the risk of future dark spots
- Use fluoride toothpaste twice a day and spit out the excess.
- Clean between teeth daily.
- Reduce how often teeth are exposed to sugary foods and drinks.
- Avoid tobacco.
- Attend check-ups at intervals based on your individual risk.
- Ask about fluoride or fissure sealants when clinically appropriate.
- Have damaged fillings and new symptoms assessed rather than waiting for pain.
Frequently asked questions
Is every black spot a cavity?
No. Stain, tartar, restorations, cracks and trapped debris can also look dark. A dentist must examine the area to identify the cause.
Can a black cavity heal by itself?
An early area of mineral loss without a hole may sometimes be arrested or reversed with fluoride and behaviour changes. A true cavitated hole does not grow back and generally requires restorative treatment.
Why is there a black spot but no pain?
Early decay and many stains are painless. Absence of pain does not prove the tooth is healthy, so a persistent new mark should be checked.