A small cavity on a tooth usually looks like a tiny area of discoloration or roughness rather than a big obvious hole.

How a small cavity usually looks

  • A tiny spot that may be white, yellow, light brown, or dark brown/black, often on the chewing surface or near the gumline.
  • Early decay can look like a chalky or matte white patch compared with the shiny surrounding enamel.
  • It may look like a small stain that does not brush off, sometimes with a very small pit or groove in the tooth.

What you might feel

  • The area can feel slightly rough or “sticky” when you run your tongue or floss over it.
  • You might notice brief sensitivity to cold, sweet foods, or biting pressure, even if there is no constant pain yet.

When it is hard to see

  • Some small cavities hide between teeth and only show up as a dark or triangular shadow on dental X‑rays.
  • Cavities can also form in deep grooves of molars where they are almost invisible without good lighting and a dental exam.

When to see a dentist

  • If you see any persistent spot, pit, or color change that does not brush away, or you have new sensitivity, a dentist should check it as soon as possible.
  • Early cavities are usually easier and cheaper to treat, and sometimes early enamel changes can even be remineralized or stopped from getting worse.

This is general information only and cannot diagnose your specific teeth. If you are worried you might have a cavity, get an in‑person dental exam as quickly as you can.

TL;DR: A small cavity often looks like a tiny, non‑removable white, brown, or black spot, sometimes with a tiny pit or rough area, and may cause mild sensitivity even before it looks like a “hole.”