Tooth decay is the most common health condition among people in the entire world. At the same time, it is the fourth most expensive condition to cure out of those that are possible to be prevented. Fluorides have proved to be an efficient measure against tooth decay since the discovery of their preventive effect in 1942, up until today. Fluorides can be applied systematically or topically. Systematic fluoride application includes consuming fluorided water, salt or milk and taking flouride supplements. Topical fluoride application presupposes using toothpaste and mouthwash, intended for individual use, as well as solutions, gels, polishing products and dental foams intended for professional use. Due to the wide range of choices and availability of different fluoridation methods, a problem of overdosing a daily amount of fluoride now appears. Dental fluorosis is an undesirable effect of fluorides on mineralization of tooth enamel. Its casuse is still not explained, although it seems that genetic preconditions, along with a high consumption of fluoride, are affecting its appearance. Hydroxyapatite is a biocompatible product that has a great remineralisation effect. The crystals of nano-hydroxyapatite, which resemble the natural enamel crystals due to their size and form, are able to fit into the area of demineralised enamel, acting as the natural enamel crystals. Due to their biocompatibility, children using toothpaste with nano-hydroxyapatite have lower chances of dental fluorosis occuring. Besides preventing tooth decay, a prophylactic effect of nano-hydroxyapatite on creating dental plaque has been noted, as well as its efficiency in the dentin hypersensitivity treatment. In vitro studies show anti-erosive effect of hydroxyapatite.