How Does Biofilm Lead to the Development of Periodontal Diseases? Flashcards
What causes periodontal tissue destruction in periodontitis?
- Direct action of microorganisms (20%)
- De-regulated inflammatory (immune) response to dental plaque microorganisms (disruption of protective innate immunity or unresolved inflammation)80%
What are the local and systemic factors of periodontitis?
Local : promotes accumulation of dental plaque (calculus, restorations with overhanging margins)
Systemic Factors : Modify host-bacteria interactions (diabetes Mellitus, puberty, pregnancy, immunodeficiency)
What are the direct & indirect actions of the bacteria that can be present in the biofilm?
Indirect activates immune response which then indirectly damages tissue.
What are periodontal diseases?
Bacterially induced, immune-mediated inflammatory diseases of the tissues supporting the teeth.
Dental plaque is the primary aetiological factor
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What are the bacterial virulence factors that can lead to development of periodontal disease?
- Attachment to host tissues
2.ability to multiply at susceptible site
3.Evasion of host defences
4.Tissue damage via enzymes, bone resorting factors, cytotoxins
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What is the model of periodontal disease?
Specific pathogenic bacteria present in sub-gingival areas produce different antigens that activate host immune response.
Host produces different cytokines, prostaglandins and enzymes which can lead to connective tissue damage and bone resorption if not controlled
Genetic and environmental factors can also influence the severity of the host inflammatory response
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What are the most important cytokines that can be produced by the host immune response?
Interleukin 1- produced by macrophages, fibroblasts & epithelial cells
Interleukin 6- produced by monocytes, fibroblasts, epithelial cells
Interleukin 8- produced by all of the above + some platelets
Interleukin 10- produced by T/B lymphocytes
PGE2- produced by macrophages, neutrophils, mast cells, epithelial cells
TNF (tumour necrosis factor)- produced by monocytes, macrophages, epithelial cells
TGF- produced by most cells
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What are the effects of interleukin 1?
-Osteogenic activation (form -osteoblasts -bone forming cells)
-Margination of neutrophils
-Prostaglandin & IL 6 release from fibroblasts
-TNF production/release
What are the effects of interleukin 6?
-Increases bone resorption
-Activates T cells & differentiation of B cells
-B cells & Ig production
What is the effect of interleukin 8?
Chemotaxis (strong) of neutrophils
What is the effect of interleukin 10?
Anti inflammatory suppression
What are the effects of PGE2?
Vascular permeability, vasodilation, chemotaxis of neutrophils, bone resorption.
What are the effects of TNF?
Increases production of IL 1, prostaglandin release, phagocytosis.
What is the effect of TGF?
Anti inflammatory repair potential
What must there be to keep periodontal tissues healthy?
A balance
2 factors which generally cause periodontal disease:
Bacterial virulence - direct
Host response - indirect
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