I'm curious about teeth whitening.

I'm a smoker and my teeth are yellow, so I'm wondering if teeth whitening will be effective and if the results will last.

I heard that after whitening, it's best to be cautious with coffee and food. Is that correct?

I can't even consider whitening because I think smoking and whitening might also affect each other.

I'm curious about how long tooth sensitivity lasts after teeth whitening and how long the sensitivity persists.

I'm also curious about how much the amount is.