Glossary

acidogenic – Something that produces acid, such as cariogenic bacteria that ferment sugars to produce acids.

aciduric – Capable of growth in an acidic environment, often referring to acid-tolerant bacteria that can survive and proliferate in the low pH conditions created by cariogenic bacteria.

buffering agent – A substance that adjusts the pH of any solution, such as saliva or plaque fluid, and can resist pH fluctuations. Beneficial in the prevention of dental caries by maintaining a neutral pH that minimizes demineralization.

carbonated hydroxyapatite – The hydroxyapatite in human enamel is not pure and contains carbonate ions. The presence of carbonate ions makes the enamel structure much more soluble and less resistant to acid dissolution. Chemically, the hydroxyapatite that comprises enamel is often described as a calcium-deficient carbonated hydroxyapatite, which is more prone to demineralization.

cariogenic bacteria – Bacteria present in the oral biofilm (dental plaque) that, when provided with fermentable carbohydrates, produce acids that lead to the occurrence of carious lesions when other necessary factors are present (such as low pH and insufficient remineralization).

demineralization – The chemical process by which minerals (mainly calcium and phosphate) are removed from the dental hard tissues - enamel, dentin, and cementum. This occurs through dissolution by acids produced by bacteria or by chelation. The rate of demineralization depends on the degree of supersaturation of the immediate environment of the tooth and the presence of fluoride, which can slow the process. In optimal circumstances, the minerals can be replaced through the process of remineralization.

dental plaque – An organized community of many different microorganisms that form a biofilm and is found on the surface of the tongue and all hard surfaces in the oral cavity. Dental plaque is present in all individuals and can vary from being comprised of health-related microorganisms (commensals) to being highly harmful (pathogenic), predisposing the patient to dental caries or periodontal diseases. Dental plaque must be removed by mechanical methods, such as toothbrushing or professional dental cleaning (prophylaxis), as it cannot be eliminated by rinsing or chemical agents alone.

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.

GERD – Gastroesophageal reflux disease; the reflux of hydrochloric acid generated in the stomach that travels to the mouth. Erosion will occur upon the acid’s contact with enamel surfaces. glycolysis – Glycolysis is essential to all living organisms and is the process whereby energy is released from sugars by the formation of pyruvate. This pathway is crucial for bacterial metabolism, especially in cariogenic bacteria, which produce acid as a byproduct.

hydroxyapatite – Crystals of calcium phosphate – (Ca₁₀ (PO₄)₆ OH₂) that form the mineral structure of teeth and bone. Enamel comprises approximately 98% hydroxyapatite (by weight). 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.

ions – Atoms or molecules that carry either a positive or a negative electric charge in a solution. For example, sodium chloride (NaCl, common table salt) in water dissociates into Na+ and Cl– ions.

pellicle – A layer of salivary glycoproteins that forms on the tooth surface and is present within minutes of oral hygiene or professional prophylaxis. The pellicle layer is protective against caries as it slows the diffusion of calcium and phosphate ions away from the tooth surface. Sometimes referred to as the Acquired Pellicle, it varies in thickness in different parts of the mouth and is reduced during oral hygiene or by dietary acids. In addition to protecting against caries, it is the layer to which microorganisms first attach to the tooth surface in the formation of the dental plaque.

remineralization – The chemical process by which minerals (mainly calcium and phosphate) are replaced into the substance of the dental hard tissues – enamel and dentin. The process requires an ideal environment that includes supersaturation with calcium and phosphate ions, and adequate buffering. In the presence of fluoride, remineralization is enhanced by the formation of fluorapatite, which is more resistant to acid attack.

translucent – Permitting the passage of light; especially transmitting and diffusing light so that objects beyond cannot be seen clearly.

white spot lesion – The earliest clinical signs of dental caries, appearing before cavitation occurs. At this stage, the disease process is reversible through remineralization, provided favorable conditions are present - such as the use of fluoride and adequate availability of calcium and phosphate ions.