According to ADA CCS, the sealant/restoration recommended for ICDAS score 2, extreme risk patients:
The ICDAS has been further condensed by the American Dental Association into the Caries Classification System (ADA CCS). Assessment of dental caries also requires identification of caries lesion activity so as to make decisions relative to treatment recommendations.
Sealant optional or caries biopsy if DIAGNOdent is 20-30
Minimally invasive restoration
Sealant or minimally invasive restoration needed
Any of the above