Preventive materials are applied to reduce the risk of dental caries and other oral disease, including pit-and-fissure sealants, fluoride varnishes and gels, and remineralizing agents such as CPP-ACP pastes. Typically used in pediatric and high-caries-risk patients, these materials are applied directly to clean tooth surfaces to physically block bacterial colonization of pits and fissures or to strengthen enamel through fluoride uptake and remineralization. Preventive materials form a distinct category from restorative materials, focused on disease prevention and early intervention rather than repairing existing structural tooth damage.