Fluoride varnish or remineralizing pastes can be used after whitening to reinforce enamel
https://www.mediafire.com/file/efo1zs05lbdd1rj/pdf-6611-3620.pdf/file
Fluoride varnish or remineralizing pastes can be applied after whitening to reinforce enamel and reduce level of sensitivity while preserving your brighter smile.