Glossary

acidogenic – Something that produces acid, such as cariogenic bacteria.

aciduric – Bacteria capable of growth in an acidic environment.

allogenic – Denoting individuals of the same species but of different genetic constitution (antigenically distinct).

anaerobic – Living in the absence of air or free oxygen.

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.

buffering capacity – Saliva and the fluid in dental plaque possess the ability to buffer. Buffering adjusts the pH of any solution such as saliva or plaque fluid and can resist changes in pH. Buffering capacity is the degree of buffering that can be brought about.

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 is 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.

dental plaque – An organized community of many different microorganisms that forms itself into 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 people and can vary from being comprised of totally healthy microorganisms (commensals) to being very harmful (pathogenic), predisposing the patient to dental caries or periodontal diseases. Note: Dental plaque is not food debris, nor does it contain food debris. Dental plaque can only be completely removed by mechanical means such as toothbrushing or prophylaxis. Food debris can be removed by rinsing.

disaccharides – Any group of carbohydrates, such as sucrose or lactose, that yield monosaccharides on hydrolysis; also called double sugars.

dysbiosis - an imbalance in the composition and function of the microbial communities, occurring when there is a disruption in the normal balance of beneficial and harmful microorganisms, leading to changes in the overall health and well-being of the host.

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

fructosyltransferase (FTF) – An enzyme that catalyzes the breakdown of fructose, liberating glucose.

glycolysis – Glycolysis is essential in all living organisms, and is the process whereby energy is released from sugars by the formation of pyruvate.

glycoprotein – Any of a group of conjugated proteins that contain a carbohydrate as the non-protein component.

glycosidic – Any of a group of organic compounds that yield a sugar and one or more non-sugar substances on hydrolysis.

invertase – An enzyme derived from yeast that has the ability to break sucrose down into the simple sugars glucose and fructose.

lipids – Any of a group of organic compounds, including the fats, oils, waxes, sterols, and triglycerides, that are insoluble in water but soluble in common organic solvents, are oily to the touch, and together with carbohydrates and proteins constitute the principal structural material of living cells.

monosaccharides – The simplest forms of carbohydrates (sugar).

pellicle – A thin, acellular membrane of salivary proteins adsorbed to the enamel or cementum.

phosphoproteins – Proteins that contain phosphate groups esterified to serine, threonine or tyrosine. The phosphate group usually regulates protein function.

pili – A hair-like appendage found on the surface of many bacteria.

polysaccharides – Chains of sugar units that are held together by glycosidic bonds.

prophylaxis – The clinical procedure that removes plaque, calculus and stain in a procedure carried out by a dental professional.

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, and adequate buffering. In the presence of fluoride, remineralization is enhanced.

substrate – Substrate is the material metabolized by specific microorganisms in dental plaque to produce the acids that lead to demineralization. The substrate is typically a sugar such as sucrose, glucose, and fructose occurring in foods and beverages. Substrate is more of a theoretical term; in practice it is sugars that are used by the microorganisms to produce acid in the process of dental caries.