'caries-preventive' is a modern English compound formed from 'caries' + 'preventive'. 'caries' originates from Latin, specifically the word 'caries', where it meant 'decay, rottenness'; 'preventive' ultimately originates from Latin 'praevenire' (via Old French 'prevenir'), where 'prae-' meant 'before' and 'venire' meant 'to come'.

'caries' came into English from Late Latin 'caries' meaning 'rottenness' and was adopted in medical/dental contexts to mean tooth decay; 'preventive' developed from Latin 'praevenire' to Old French 'prevenir' and into Middle English 'prevent', later forming the adjective 'preventive'. The compound 'caries-preventive' is a modern descriptive formation in English combining these elements.

Initially, 'caries' meant 'rottenness' in Latin and more generally 'decay'; over time it narrowed to the dental sense 'tooth decay'. 'Preventive' originally carried the sense 'to come before' and evolved to mean 'intended to stop or hinder something from occurring'; together the compound now means 'intended to prevent tooth decay'.