Teeth are made of layers.
The outer layer, enamel, is what you see when you smile. But enamel is not completely opaque. It is slightly translucent.
Beneath the enamel sits dentine, which has a naturally warmer, more yellow tone.
When you are younger, enamel tends to reflect light more evenly and soften the colour underneath. This is one reason teeth often look brighter earlier in life.
But over time, two things can begin happening at once.
First, years of tea, coffee, wine, and other everyday staining can build up on the surface.
Second, the enamel itself can change, allowing more of the natural warmth underneath to show through.
So the issue is not always just “stains.”
It is often surface staining plus age-related changes in how the tooth reflects light.
What can be done?
Many people keep trying stronger whitening products. But if those products are only designed to treat one part of the issue, they may never fully solve it.