Dental Plaque Biofilms Teradaj Aticharoenkul

Periodontal disease chronic imflammatory lesions destruction supporting periodontal tissues associated with specific microbial complexes in subgingival biofilms

Bacterial species Actinobacillus actinomycetemcomitans Actinomyces odonlyticus Actinomyces naeslundii Capnocytophaga gingivalis Fusobacterium nucleatum

Bacterial species Streptococcus mitis Eubacterium nodatum Propionibacterium acres Porphyromonas gingivalis Treponema denticola

Gram negative oral spirochete predominant of human periodontal disease infection and inflammation of gingiva occurs in 80% of the adult population lives and can evolve to severe

Treponema denticola refractory periodontitis acute necrotizing gingivitis bone resorption and tooth loss

Biofilm communities Comprises : bacterial microcolonies, extracellular slime layer, fluid channels and primitive communication system

Biofilm communities bacteria attach to a surface mushroom-shaped microcolonies different microcolonies may contain different combinations of bacterial species the slime layer protects the bacterial microcolonies from antibiotics,antimicrobials,and host defense mechanisms

Biofilm communities bacteria in the center of a microcolony may live in a strict anaerobic environment while other bacteria at the edges of the fluid channels may live in an aerobic environment

Biofilm communities the biofilm structure provides a range of customized living environments (with differing pHs, nutrient availability, and oxygen) within which bacteria with different physiological needs can survive fluid channels penetrates the extracellular slime layer

Biofilm communities fluid channels provide nutrients and oxygen for the bacterial micro colonies and facilitate movement of bacterial metabolites, waste products, and enzymes within the biofilm structure Each bacterial microcolony uses chemical signals to create a primitive communication system used to communicate with other bacterial microcolonies

Phases of plaque formation

The pattern of biofilm development

absorption of salivary proteins and glycoproteins some bacterial molecules, to the tooth surface (the acquired pellicle) long-range (>5Onm), non- specific interaction of microbial cell surfaces with the acquired pellicle shorter-range (10-20nm) interactions result in reversible adhesion to the surface. irreversible adhesion adhesins on the cell surface and receptors in the acquired pellicle. secondary or late-colonisers attach to primary colonisers (coaggregation) Cell division of the attached cells to produce confluent growth, and a bioflim.