Most brown and black spots on teeth turn out to be surface stain, tartar, or stain settled into the natural grooves of the back teeth. A smaller share are decay, old lesions that have stopped progressing, fillings showing through the enamel, or a tooth that has darkened from the inside. The clues that separate them are where the spot sits, whether its texture differs from the enamel around it, whether it is changing, and whether the tooth feels different. This guide walks through each possibility so you know what questions to bring to a dentist, who is the only one who can say which one you have.
What usually causes brown spots on teeth?
Color on a tooth comes either from the outside, in the form of pigment stuck to or in the surface, or from the inside, when the tooth structure itself changes. Outside stain is far more common and usually easier to deal with.
- Food and drink pigmentsCoffee, tea, red wine, cola, soy sauce and dark berries leave pigments that bind to the thin protein film that coats teeth. Stain builds fastest where brushing is weakest, such as along the gumline and the backs of the lower front teeth.
- Tobacco and nicotine productsTar and nicotine produce yellow-brown to dark brown stain that tends to be heavier and more widespread than food stain.
- TartarPlaque left in place hardens into calculus, which is porous and soaks up pigment. Above the gumline it looks yellow to brown. Below the gumline it is often dark brown or black.
- Certain rinses and supplementsChlorhexidine mouthwash, some liquid iron supplements and certain other rinses are known for causing brown surface staining with regular use. The stain is on the surface and usually polishes off.
- Stained enamel defectsEnamel that formed with small irregularities, including more pronounced fluorosis, can take up stain and look brown in patches.
- DecayA cavity can look tan, brown or darker as it progresses, especially in grooves, between teeth and on exposed roots.
What does a black spot on a tooth mean?
Black spots feel more alarming than brown ones, but the most common causes are still benign. The difference is mostly about where the spot is.
How can you tell a stain from a cavity?
You often cannot, with certainty, from home. A dentist uses a combination of drying the tooth, good lighting, magnification, gentle tactile checks and X-rays, and sometimes compares with photos from a previous visit. Still, a few patterns point in one direction or the other.
- It shows up on several teeth in a similar pattern
- The surface feels smooth and hard, the same as the enamel around it
- It has looked the same for months or years
- It lightened or disappeared after your last professional cleaning
- You drink coffee or tea daily, smoke, or use a staining rinse
- A single spot on one tooth that is new or getting larger
- A rough, chalky or soft-feeling area, or a visible pit
- Floss catches or shreds at that tooth
- The tooth twinges with sweets, cold or heat
- A dark line along the edge of an older filling or crown
Picking at a spot with a fingernail, pin or home dental tool is a bad trade. You can scratch enamel, push bacteria under the gum, or break through the surface of an early lesion that might otherwise have stayed intact. Tartar needs professional instruments to come off safely.
Why would a whole tooth turn gray, brown or black?
When one tooth darkens overall rather than showing a spot, the cause is usually inside the tooth. The most common story is an old knock to the tooth, sometimes one you do not remember. An injury can disrupt the blood supply to the nerve, and breakdown products from the pulp tissue gradually stain the dentin from within, so the tooth drifts toward gray or brown over months or years.
Other internal causes include a large old filling or a root canal-treated tooth, which can darken with time, and certain medications taken during childhood while teeth were forming, which cause banded discoloration across several teeth. A darkened single tooth is not usually an emergency, but it is worth a dentist's exam and an X-ray, because the nerve inside may need attention even when nothing hurts. Where the tooth is healthy otherwise, dentists have ways to lighten it from the inside or cover it that surface whitening alone does not replicate.
What can you do at home, and what needs a dentist?
For stain on the outside of the tooth, home care does a surprising amount. For anything structural, it does not, and trying harder at home just delays the answer.
- Rinse with water after dark drinksA quick swish after coffee, tea or wine clears pigment before it settles. Waiting 30 minutes or so before brushing after acidic drinks is kinder to enamel.
- Brush thoroughly along the gumlineMost stain starts where the brush skips. A soft brush angled toward the gumline, two minutes twice a day, keeps new stain from building.
- Clean between teeth dailyFloss or small interdental brushes remove plaque before it hardens into tartar in the spaces where stain collects.
- Use a whitening toothpaste modestlyThese polish surface stain with mild abrasives. They help with extrinsic stain but do not change decay, tartar or internal color, and heavy scrubbing with them wears the surface.
Anything that needs removal, filling, bonding or internal lightening is a dentist's job. A professional cleaning lifts tartar and stubborn stain in one visit, and an exam tells you whether a dark spot is cosmetic, needs monitoring or needs treatment. OneOral members can send a photo to a licensed dentist through messaging, which helps decide whether a spot can wait for a routine checkup or should be seen sooner.
Book prompt in-person care if a dark spot comes with pain that lingers, throbs or wakes you, a tooth that hurts to bite on, a bad taste or pimple-like bump on the gum, or swelling. Facial or jaw swelling that spreads, fever, or difficulty swallowing or breathing needs urgent or emergency care the same day.
Will whitening remove brown spots on my teeth?
Are black spots on my child's teeth cavities?
A black spot on my molar doesn't hurt. Is it fine?
Can a dentist remove brown spots in one visit?
Ready to Transform Your Oral Health?
Join thousands of members who are preventing cavities with OneOral.