biofilm – An aggregation of microorganisms in which cells adhere to each other forming small communities that are held together by an extracellular polymeric matrix. Different communities are co-dependent on each other, and the whole biofilm forms a defensive mechanism requiring much higher concentrations of antimicrobials to control its growth. Dental plaque is a classic biofilm.

demineralization – The chemical process by which minerals (mainly Calcium) are removed from the dental hard tissues – enamel, dentin, and cementum. The chemical process occurs through dissolution by acids or by chelation, and the rate of demineralization will vary due to the degree of supersaturation of the immediate environment of the tooth and the presence of fluoride. In optimal circumstances, the minerals may be replaced through the process of remineralization.

dental fluorosis – An abnormal condition caused by the excessive intake of fluorine, such as from fluoridated drinking water, during the period in which tooth buds are developing (amelogenesis), and is characterized in the developed tooth chiefly by mottling of the enamel. This condition can range from white flecks in the enamel (mild fluorosis) up to brown, stained and pitted enamel (severe).

enzyme – Protein that catalyzes, or facilitates, biochemical reactions.

fluoride – The anion of the halogen fluorine (F-). Compounds containing the fluoride anion are collectively called fluorides. Fluoride compounds very commonly occur, from simple fluoride toothpastes to PTFE (Teflon).

fluoride dentifrice – A toothpaste that has been formulated to deliver clinically proven amounts of fluoride into the oral cavity, and to bind to tooth surfaces creating fluorapatite and Calcium fluoride, both of which protect the tooth from the acids produced by cariogenic bacteria.

fluoride supplements – The diet of children can be supplemented with sodium fluoride, similar to vitamin supplementation, in areas where water fluoridation, or availability of fluoride by other means, such as milk or salt, may not be available.

fluorapatite – A crystal structure in tooth mineral [Ca10 (PO4)6 F2] resulting from the replacement of hydroxyl ions (OH-) in the hydroxyapatite structure with fluoride ions (F-). Fluorapatite (also commonly referred to as fluoroapatite, fluorhydroxyapatite or fluorohydroxyapatite) is stronger and more acid resistant than hydroxyapatite.

hydroxyapatite – Crystals of calcium phosphate - [Ca10(PO4)6 OH2] - that form the mineral structure of teeth and bone. Enamel comprises approximately 98% hydroxyapatite. Much of the hydroxyapatite in enamel, however, is a calcium-deficient carbonated hydroxyapatite, the crystals of which are readily dissolved by acids. The addition of fluoride creates fluorapatite, which is less soluble and more acid-resistant.

hypomineralization – Relating to or characterized by a deficiency of minerals.

milk fluoridation – Milk provides an ideal vehicle to deliver the correct amount of fluoride to children. However, well-controlled studies have not yet been conducted to confirm the anticaries benefits of this approach, and this is necessary before this method can be recommended for implementation in the United States.

mottled enamel – A chronic endemic form of hypoplasia (incomplete development) of the dental enamel caused by excessive intake of fluoride by a child during key stages of tooth formation. It is characterized by defective calcification that results in a chalky appearance to the enamel, which gradually undergoes brown discoloration.

remineralization – The chemical process by which minerals (mainly Calcium) are replaced into the substance of the dental hard tissues - enamel, dentin and cementum. The process requires an ideal environment that includes supersaturation with calcium and phosphate ions, the presence of fluoride, and adequate buffering.

water fluoridation – The addition or removal of fluoride from domestic water supplies to achieve the optimal concentration of fluoride. The optimal concentration varies due to ambient temperature of the climate and thus water intake. Hexafluorosilicic acid (H2SiF6) and its salt sodium hexafluorosilicate (Na2SiF6) are the more commonly used additives, especially in the United States.