fluoridize

transitive verb

flu·​o·​ri·​dize

variants or British fluoridise

-ə-ˌdīz 

fluoridized or British fluoridised; fluoridizing or British fluoridising

: to treat (as the teeth) with a fluoride

fluoridization noun

or British fluoridisation

ˌflu̇(-ə)r-ə-də-ˈzā-shən