Biofilm Flashcards
Basic properties of biofilm
- Cooperating community
- Microcolonies
- Protective matrix
- Differing environments
- Resistant to antibiotics, antimicrobials, and host defence
- Bulk of biofilm made of water
Basic composition of plaque
- Microorganisms(mycoplasma, yeast, protozoa, viruses)
- Host cells (macrophages, leukocytes, epithelial cells)
- Organic compounds (polysaccharides, glycoproteins)
- Inorganic compounds (calcium, phosphorus, sodium)
Classification of dental plaque
- Marginal plaque
- Supragingival plaque
- Subgingival plaque
Supragingival plaque (aerobic)
- S. sangunis
- S. mutans
- Actinomyces viscosus
Subgingival plaque (anaerobic)
- Fusobacterium spp.
- Prevotella intermedia
- Anaerobic spirochetes
Red complex
PTT
- Porphyromonas gingivalis
- Treponema denticola
- Tannerella forsythia
Orange complex
- Prevotella spp.
2. Fusobacterium spp.
Yellow complex
S. mitis, S. oralis, S. sanguinis
S. gordonii, S. intermedius
Factors favouring plaque accumulation
- Pits and fissures
- Malocclusion
- Overhanging restorations
Plaque (biofilm) formation
- Association
- Adhesion
- Proliferation
- Micro-colonization
- Biofilm maturation
Association
Formation of acquired pellicle (Thin layer of salivary glycoproteins and GCF) . Hydroxyapatite crystals
Adhesion
Reversible attachment to pellicle by Van der waals and electrostatic forces. Fimbrae attaches to proline rich proteins (receptors)
Initial colonizers include Streptococcus and Actinomyces spp. Gram positive rods and cocci
Initial colonizers derive nutrition from glycoproteins and simple sugars
Proliferation
Lateral growth to cover tooth surface
Microcolonization
S. mutans produce extracellular polysaccharide like glucans and fructans which aid in adhesion of more bacteria and as an energy source for more colonies
Biofilm maturation
Secondary colonizers attach by co-aggregation