For an incipient (early, non-cavitated) caries lesion, what is the BEST treatment?

For incipient pit-and-fissure caries (non-cavitated), sealants are the treatment of choice. They physically seal bacteria out and arrest progression. Fluoride varnish is excellent for smooth surface prevention/remineralization. SDF is for cavitated caries (especially pediatric). Stannous fluoride is preventive. For pits/fissures with incipient lesions → sealant is gold standard.