What Does a Cavity Look Like?

By the time a cavity looks obvious, it has usually been there a while.

Quick Answer

A cavity starts as a chalky white spot on the enamel, then darkens to brown or black as it deepens, and eventually forms a visible hole or a dark shadow near the gumline. Many cavities hide between teeth or under the gumline where you cannot see them, which is why X-rays catch what a mirror misses.

The stages you can see

First comes a dull white patch where acid has pulled minerals out of the enamel. It looks lighter than the surrounding tooth and has no shine. That stage can still be reversed.

Next it stains brown or black as it absorbs pigment and deepens. Then the surface collapses into a pit or hole you can feel with your tongue or catch floss on.

What a cavity is not

Not every dark spot is decay. Surface stain from coffee and tea sits on the enamel and wipes off during a cleaning. Old amalgam fillings show as gray shadows. Harmless pits and grooves in molars can look dark without being decayed.

White spots can also come from too much fluoride in childhood or from braces, as covered in white spots on teeth.

The ones you cannot see

The most common cavities start between teeth, where the surfaces touch and a brush cannot reach. They are invisible from the front and often painless until they get deep. Only X-rays or floss catching in the same spot reveal them.

Cavities under old fillings and along the gumline hide the same way.

When to get it checked

Book a visit for a persistent dark spot, a hole you can feel, food that keeps packing in one place, or sensitivity to sweets and cold. Catching decay early means a filling rather than a crown or a root canal.

See how to prevent cavities and whether a cavity can be reversed.

Frequently Asked Questions

Can you see a cavity yourself?

Sometimes. Visible cavities appear as white, brown, or black spots or holes on the chewing surface. Cavities between teeth and under the gumline usually need X-rays to detect.

Do all cavities hurt?

No. Early and moderate decay is often painless. Pain usually starts once the cavity nears the nerve, which is why routine checkups matter.

Is a black spot on a tooth always a cavity?

Not always. It may be surface stain, an old filling, or a natural groove. A dentist can tell the difference with an exam and, if needed, an X-ray.