Dental plaque
Plaque is not a mineral, bacterial aggregation on the teeth and other hard structures in the mouth, which is so tenaciously adhesion to surfaces that it resists removal of the salivary flow or tender, as the spray of water across its surface.
About 70% of the plaque consists of bacterial cells. The remainder consists of extracellular proteins and polysaccharides, which act as a matrix for cell component. In addition, the plaque contains a small amount of epithelium and white blood cells, which are derived from crevicular fluid. Accurate structural, biological and biochemical composition of the dental plaque is the subject of a large variation in dependence on concentration of bacteria in the saliva; the place and duration of plaques; nature competitive flora; oxygen and nutrient availability, the composition of the diet; and the presence of periodontal disease.
Early Deposit form on the cleaned surface of the tooth is the?purchased film`. It structureless film salivary glycoproteins selectively adsorbed on the surface of the hydroxyapatite crystals, and is visible in several minutes after the Polish with pumice.
Film formation is accompanied bacterial colonization as micro-organisms in saliva absorbed film. After 3 or 4 hours a thin layer of plaque is composed mainly gram-positive cocci (mainly, streptococci) will be created. They remain the dominant micro-organisms in about 7 days, though, during this time, there is a proportional increase in gram-positive rods and Gram-negative cocci and bacilli. After 7 days of threads, fusobacteria, and spirilla occur in large numbers. As plaque Matures further, spirohet and vibrios appear, and filamentous bacteria, especially Actinobacteria, may become predominant.
It is obvious that there are numerous mechanisms for antibacterial therapy: Streptococcus sanguis adapted to comply with hydroxyapatite and is a pioneer among bacteria can be found in the deeper layers boards; some organisms interact with salivary components, which are used as a binder material; and the emergence of plaque Streptococcus mutans depends on sucrose, from which it synthesizes the extracellular polysaccharides to mediate their investments. Synthesis of polymer surface may also take into account the ability of bacteria of one type to associate with each other, or bacteria another kind. Cob structures, filamentous bacteria covered cocci, are an example of such interspecific binding. In addition to the extracellular polysaccharides, plaque contains intracellular polysaccharides, in the form of storage granules, synthesized from the diet of sugar.
Bacteriological research of plaque in the course of the development of gingivitis suggest that there are more than 200 different species in Mature plaque. Gingivitis is that the quantitative changes in plaque, and not from the overgrowth of specific microorganisms. Periodontitis is caused subgingival down growth of those bacteria that are best able to bypass the security forces of his body and survive in low-oxygen environment. Thus, the composition of subgingival plaque is different from a RAID on adjacent visible surface of the tooth. For example, in subgingival plaque, Gram-positive bacteria found in smaller proportions; and gram-negative bacteria in a higher percentage than of supragingival plaque. Subgingival flora constitute layer teeth-attached RAID and poorly adherent component in direct connection with pocket epithelium. Teeth-attached RAID consists mainly Gram-positive rods and cocci, while free plaque consists mainly Gram-negative microorganisms, including mobile forms. Many different species of bacteria is considered to be important in the etiology of diseases of parodont.
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