Dental plaque

From Wikipedia, the free encyclopedia

Improper removal of plaque caused a build up of calculus (dark yellow colour) near the gums on almost all the teeth.

Dental plaque is a biofilm (usually of a clear color) that builds up on the teeth. If not removed regularly, it can lead to dental cavities (caries) or periodontal problems (such as gingivitis).

The microorganisms that form the biofilm are almost entirely bacteria (mainly streptococcus and anaerobes), with the composition varying by location in the mouth.

The microorganisms present in dental plaque are all naturally present in the oral cavity, and are normally harmless. However, failure to remove plaque by regular toothbrushing means that they are allowed to build up in a thick layer. Those microorganisms nearest the toothsurface convert to anaerobic respiration; it is in this state that they start to produce acids which consequently lead to demineralization of the adjacent tooth surface, and dental caries. Saliva is also unable to penetrate the build up of plaque and thus cannot act to neutralize the acid produced by the bacteria and remineralize the tooth surface.

Plaque build up can also become mineralized and form calculus.

Frequency of brushing and flossing with good technique is important, because the nature (ie composition) of the microorganisms change as the plaque gets "older." Therefore, plaque which is 12 hours old for example is much less damaging than plaque which has not been removed in days.

Before oral hygiene practices, human teeth did not last as long, although part of the necessity for tooth cleaning may be attributed to changes in diet, such as higher-sugar foods.