I'm 고민 about teeth whitening.

It seems that my teeth become more yellow as I age.

There is a lot of interest in teeth whitening.

Maybe because I usually drink a lot of kimchi and coffee.

I'm worried that maintaining teeth whitening might not be difficult, but I can't live without eating, and I'm concerned that eating dark-colored foods might cause my teeth to revert back to their original color.

How long does the whitening effect last after getting teeth whitening?