Dental Plaque
Dental plaque is a general term for the diverse microbial community (predominantly bacteria) found on the tooth surface, embedded in a matrix of polymers of bacterial and salivary origin. Plaque develops naturally on teeth, and forms part of the defence systems of the host by helping to prevent colonisation of enamel by exogenous (and often pathogenic) microorganisms (colonisation resistance).
Plaque is an example of a biofilm; current research is showing that the properties of bacteria associated with a surface in a biofilm can be markedly different than those of the same cells growing in liquid broth (planktonic cells). Plaque is found preferentially at protected and stagnant surfaces, and these are at the greatest risk of disease.
Dental plaque is a general term for the diverse microbial community (predominantly bacteria) found on the tooth surface, embedded in a matrix of polymers of bacterial and salivary origin. Plaque develops naturally on teeth, and forms part of the defence systems of the host by helping to prevent colonisation of enamel by exogenous (and often pathogenic) microorganisms (colonisation resistance).
Plaque is an example of a biofilm; current research is showing that the properties of bacteria associated with a surface in a biofilm can be markedly different than those of the same cells growing in liquid broth (planktonic cells). Plaque is found preferentially at protected and stagnant surfaces, and these are at the greatest risk of disease.
How Plaque is formed
- absorption of salivary proteins and glycoproteins, together with some bacterial molecules, to the tooth surface to form a conditioning film (the acquired pellicle).
- Long-range (>5Onm), non-specific interaction of microbial cell surfaces with the acquired pellicle via van der Waals attractive forces.
- Shorter-range (10-20nm) interactions, in which the interplay of van der Waals attraction forces and electrostatic repulsion produces a weak area of attraction that can result in reversible adhesion to the surface.
- Irreversible adhesion can occur if specific inter-molecular interactions take place between adhesins on the cell surface and receptors in the acquired pellicle.
- Secondary or late-colonisers attach to primary colonisers (coaggregation), also by specific inter-molecular interactions.
- Cell division of the attached cells to produce confluent growth, and a bioflim
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