Fluoride varnish or remineralizing pastes can be used after whitening to reinforce enamel
https://zanderckjg432.timeforchangecounselling.com/the-ultimate-guide-to-professional-teeth-whitening-what-to-expect-3
Fluoride varnish or remineralizing pastes can be used after whitening to strengthen enamel and lessen sensitivity while keeping your brighter smile.