All of the following are appropriate treatment options for a white-spot lesion EXCEPT:

Systemic fluoride is indicated during tooth formation to reduce caries risk in high-risk children — it does not remineralize an existing post-eruptive white-spot lesion. Topical fluoride, micro-abrasion, and resin infiltration all directly treat the existing demineralized surface. In an adult, systemic supplementation would additionally risk fluorosis elsewhere.