Is it a procedure where the upper surface of the tooth is ground down and something is attached?

I don't understand the basic concept of the procedure.

It would be helpful if someone knowledgeable could let me know.

Typically, how old can one usually do it?

My teeth are in poor condition and discolored due to aging.

Maybe because I drink a lot of coffee, there are also many stains.

We need an easy and cost-effective solution.