Fluoride varnish or remineralizing pastes can be used after whitening to reinforce enamel

https://manuellinq708.huicopper.com/the-length-of-time-does-teeth-whitening-last-a-sensible-timeline

Fluoride varnish or remineralizing pastes can be used after whitening to enhance enamel and lessen level of sensitivity while keeping your brighter smile.