Fluoride varnish or remineralizing pastes can be applied after whitening to enhance enamel

https://andersonwmsf170.yousher.com/how-to-whiten-your-teeth-before-a-significant-event-or-wedding-1

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