ameloblasts – The cells in the embryonic tooth germ that produce enamel. Once tooth formation is complete, the ameloblasts are unable to produce further enamel. Therefore, if enamel is lost or damaged by caries, tooth wear, or trauma, it cannot be repaired or replaced.

cariogenic – The ability to cause dental caries. A cariogenic diet contains sugars. Some bacteria in dental plaque (S. mutans) are cariogenic. The mere presence of cariogenic sugars or cariogenic bacteria are not enough to cause the initiation of the caries process. Many other factors play a role, and taken together they may or may not contribute to the process that leads to dental caries.

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.

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.

parasympathetic nerves – The part of the nervous system that controls and regulates various organs and glands unconsciously, such as the secretion of salivary and lachrymal fluids.

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.

sympathetic nerves – The part of the nervous system that controls the stress and flight-or-fight response. It controls the force of contraction and rate of the heartbeat, and dilates the pupils and the bronchioles.