Sealants are resin coatings resembling white nail polish (sometimes clear, or colored) that are applied to deep, inaccessible pits and fissures in teeth so food can't get lodged in them as easily.
If the pits or fissures in the teeth cannot be completely cleaned with a toothbrush, sealants may be recommended.
Fluoride therapy is the delivery of fluoride to the teeth, topically or systemically, to protect them from dental caries(cavities). Strictly speaking, fluoride therapy repairs rather than prevents damage to the teeth, causing the mineralfluorapatite to be incorporated into damaged tooth enamel. Fluorapatite is not a natural component of human teeth, although it is found in the teeth of sharks.
In topical fluoride therapies, fluoride is applied directly to the surface of the teeth, most commonly by means of a fluoride toothpaste. Other topical fluoride therapies include fluoridated mouth rinses, lozenges, gels, foams, and varnishes
Space maintainers are recommended when primary (baby) molar teeth are lost prematurely (e.g. because of large, unfixable cavities) or are congenitally missing. The goal of space maintainers is to prevent movement of the adjacent permanent "first molars" (also called "six-year molars"), and loss of space for (permanent) bicuspids and permanent canines.