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Precipitation of the calcium and phosphate ions within the deep layers of plaque. (80% minerals and 20% organic debris ).

Plaque development

Seconds: pellicle

formation.

1 minute: pioneer

) bacteria Ssanguis(.

2 hours : Microcolonies are

formed and extracellular

polysaccharide isreleased.

- Microcolonies increase in the

biomass.- Extracellular

polysaccharides release the organic

acids.

4 hours Biofilm development : complex microbial community)

,found on the tooth surface embedded in a matrix of polymer

(of bacterial and salivary origin

48 hours : Mature plaque

formation

Plaque metabolism

Carbohydrate (mainly sucrose) is the main source of nutrition for

oral microorganisms.

Sucrose is broken down by bacterial enzymes to glucose and

fructose.

Glucose and fructose:1 -Used as source of energy.

2 -Enter the process of glycolysis (converted to pyruvic then lactic acids).3 - Converted to polysaccharide (glucan and fructan which are either

water soluble or water insoluble, the water insoluble (protein binding) is important in plaque accumulation and attachment of the bacteria to

teeth surface.

It effects as : -Reservoir to a bacterial product as toxins and harmful substance to the host.

-Tissue damage and cause periodontal diseases

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by mechanical methods as.– Toothbrushes.– Dental floss.– Rubber tip stimulator.

Enzymes are used as antiplaque preparations. The enzymes are able to breakdown the already formed matrix in plaques and

calculus. Some have bactericidal action: Mucinase, mutanase and dextranase

Anti-plaque agents

Antimicrobial as chlorhexidine. The chlorhexidine prevents bacterial proliferation on the tooth surface by damaging

the bacterial cell membrane.

Plaque disruption as sodium lauryl sulfate.

solubilizesplaque to reduce its accumulation .

Anti-adherent as fluoride-containing compounds .

prevent or block interaction between bacteria and oral environment.

DONE BY

GHADEER HASSAN