.This trick takes care of the WHOLE problem of teeth yellowing... and doesn’t just fight external yellowing... but also — (and more importantly) — “internal yellowing.” See...
Underneath the top layer of your teeth is a layer called dentin...
Here’s how dentin causes yellowing of your teeth...
When your enamel wears down... it becomes “see-through”.
So you start to see the color of the dentin layer underneath.
When you were younger… this dentin layer was a light yellow or brown… and it was hardly noticeable because your enamel was healthy.