Periodontitis and Dental Biofilm Quiz
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Questions and Answers

What is periodontitis?

  • A microbial infection triggering an inflammatory response causing irreversible destruction (correct)
  • A form of periodontitis that affects only the soft tissues
  • A type of gum disease characterized by benign inflammation
  • A microbial infection that leads to reversible damage in the periodontium

    • What defines a plaque biofilm?

  • An organized community of microorganisms within an extracellular slime layer (correct)
  • A disorganized mass of bacteria that does not adhere to surfaces
  • A structure formed solely from dead bacteria in the oral cavity
  • A random collection of microorganisms floating in saliva

    • Which of the following best characterizes the host defense in the oral cavity?

  • It consists solely of the innate immune response
  • It includes only the acquired immune response
  • It relies exclusively on saliva for protection
  • It is a combination of innate and acquired immune responses (correct)

    • Which bacteria are typically associated with the pathogenesis of periodontal disease?

    <p>A mix of bacteria with varying virulence factors</p> Signup and view all the answers

    What role do cytokines play in the host response?

    <p>They are key signaling molecules that mediate inflammation</p> Signup and view all the answers

    What are matrix metalloproteinases (MMPs) primarily involved in?

    <p>Degrading extracellular matrix components in tissue</p> Signup and view all the answers

    What basic factors may contribute to the initiation of periodontitis?

    <p>A combination of host factors and environmental influences</p> Signup and view all the answers

    What is a key feature of the periodontal ligament's response to microbial infection?

    <p>It undergoes progressive and irreversible destruction</p> Signup and view all the answers

    What transformation occurs in the junctional epithelium that compromises its protective function?

    <p>It transforms into pocket-lining epithelium.</p> Signup and view all the answers

    Which cells are responsible for secreting cytokines and Tumour Necrosis Factor in gingival tissues?

    <p>Keratinocytes</p> Signup and view all the answers

    What is one of the primary roles of saliva in the oral cavity?

    <p>To prevent drying of oral tissues</p> Signup and view all the answers

    What term is used to describe the immune response that is specific to particular pathogens?

    <p>Adaptive immunity</p> Signup and view all the answers

    Which mechanism does the humoral immune response utilize?

    <p>Antibody production</p> Signup and view all the answers

    What is the fourth stage of dental plaque biofilm formation?

    <p>Mature biofilm – mushroom shaped colonies</p> Signup and view all the answers

    Which of the following is NOT a component of the intra-cellular matrix of dental plaque biofilm?

    <p>Calcium</p> Signup and view all the answers

    What type of bacteria primarily supports the subgingival environment?

    <p>Anaerobic bacteria</p> Signup and view all the answers

    Which of the following parts of the gingival epithelium covers the free and attached gingivae?

    <p>Oral epithelium</p> Signup and view all the answers

    Which bacterial species is known for producing gingipains to utilize GCF as a nutrient source?

    <p>Porphyromonas gingivalis</p> Signup and view all the answers

    What describes the junctional epithelium within the gingival epithelium?

    <p>At the base of the sulcus</p> Signup and view all the answers

    What is one function of the carbohydrate capsule produced by Porphyromonas gingivalis?

    <p>Resists some host defenses</p> Signup and view all the answers

    Calcium is part of which category in the composition of dental plaque biofilm?

    <p>Inorganic components</p> Signup and view all the answers

    What type of immune response is initiated by plaque in the first instance?

    <p>Innate immune response</p> Signup and view all the answers

    Which component forms as a result of acute inflammation and has a function in flushing out microorganisms?

    <p>Gingival crevicular fluid (GCF)</p> Signup and view all the answers

    What role do PMNs play in the cellular response during the initial immune defense?

    <p>Directly attacking and removing invading microorganisms</p> Signup and view all the answers

    Which species has a leukotoxin that can kill white blood cells?

    <p>A actinomycetemcomitans</p> Signup and view all the answers

    What mechanism does Treponema denticola use to disrupt host defenses?

    <p>Inducing and degrading cytokines</p> Signup and view all the answers

    How does the epithelium defend against plaque microorganisms?

    <p>Creating an intact physical barrier</p> Signup and view all the answers

    What is a significant outcome of the presence of Tannerella forsythia in the oral cavity?

    <p>Suppresses the early PMN response</p> Signup and view all the answers

    Which of the following substances are found in GCF that help defend against microorganisms?

    <p>Antibodies and breakdown products</p> Signup and view all the answers

    What is the primary action of pro-inflammatory cytokines during periodontitis?

    <p>Contribute to tissue destruction</p> Signup and view all the answers

    Which cytokines are classified as anti-inflammatory?

    <p>IL-4 and IL-10</p> Signup and view all the answers

    What factor disturbs the dynamic equilibrium in periodontal health?

    <p>Increased pathogenicity of microorganisms</p> Signup and view all the answers

    Which of the following is a proposed issue with the Non-specific Plaque Hypothesis?

    <p>It fails to explain all cases of periodontitis</p> Signup and view all the answers

    What is one role of prostaglandins, like PGE_2, in periodontal disease?

    <p>Increasing vascular permeability</p> Signup and view all the answers

    What do matrix metalloproteinases (MMPs) primarily do in the context of periodontitis?

    <p>Degrade connective tissue</p> Signup and view all the answers

    Which factor does NOT contribute to the initiation of periodontitis?

    <p>Enhanced host immune response</p> Signup and view all the answers

    What is the key characteristic of the Specific Plaque Hypothesis?

    <p>Only specific bacteria are linked to periodontal diseases</p> Signup and view all the answers

    Study Notes

    Periodontitis

    • Periodontitis is a bacterial infection that triggers an inflammatory response in the periodontium, leading to irreversible damage of the periodontal ligament and alveolar bone.

    Dental Plaque Biofilm

    • Plaque biofilm is a community of microorganisms embedded in a glycocalyx on teeth surfaces.
    • Plaque biofilm is composed of organic and inorganic components:
      • Organic: polysaccharides, proteins, glycoproteins, lipids
      • Inorganic: calcium, sodium, phosphorous, potassium
    • Formation of plaque biofilm occurs in four stages:
      • Initial attachment of bacteria to pellicle
      • Initial colonization of the tooth surface
      • Secondary colonization with extracellular slime layer formation
      • Mature biofilm with mushroom-shaped colonies

    Tissues of the Periodontium

    • Gingival epithelium:
      • Oral epithelium: covers free and attached gingiva
      • Sulcular epithelium: lines the gingival sulcus
      • Junctional epithelium: at the base of the sulcus
    • Other periodontal tissues include:
      • Periodontal ligament
      • Root cementum
      • Alveolar bone

    Bacteria Associated with Periodontal Disease

    • Subgingival environment favors anaerobic bacteria.
    • Common bacteria associated with periodontal disease include:
      • Porphyromonas gingivalis
      • Aggregatibacter actinomycetemcomitans
      • Treponema denticola
      • Tannerella forsythia
      • Fusobacterium nucleatum
      • Prevotella intermedia
    • Virulence factors enable bacteria to:
      • Colonize the periodontium
      • Invade tissues
      • Damage periodontal structures
    • P. gingivalis:
      • Produces gingipains to utilize gingival crevicular fluid
      • Contains LPS, haemagglutinins, and platelet aggregators
      • Possesses fimbriae for tissue invasion
      • Can suppress early polymorphonuclear leukocyte response
    • Tannerella forsythia: Produces proteases and an apoptotic-inducing factor
    • Treponema denticola:
      • Adheres to fibroblasts
      • Invade tissues
      • Disrupt host defense by manipulating cytokines
      • Delay wound healing
    • A. actinomycetemcomitans:
      • Produces leukotoxin, destroying white blood cells
      • Possesses toxins that damage fibroblasts and epithelial cells
      • Produces proteases, including collagenase
      • Can invade epithelial cells

    Host Defenses in the Oral Cavity

    • Innate Immune Response:
      • Saliva: Contains antimicrobial factors and aids in swallowing bacteria
      • Epithelium: Provides a physical barrier against bacteria
      • Inflammatory Response:
        • Fluid Component: GCF forms as a result of inflammation and washes out microorganisms
        • Cellular response: Primarily PMNs like neutrophils and macrophages attack and remove microorganisms
    • Adaptive Immune Response:
      • Activated when innate immunity fails to eliminate pathogens
      • Highly specific to individual pathogens
      • Uses humoral and cell-mediated immunity:
        • Humoral immunity: involves antibody production
        • Cell-mediated immunity: involves T-cells

    Cytokines, Prostaglandins, and MMPs

    • Cytokines:
      • Pro-inflammatory: IL-1, IL-6, TNF-α, contribute to tissue destruction
      • Anti-inflammatory: IL-4, IL-10, reduce inflammation
    • Prostaglandins (e.g. PGE2):
      • Promote bone resorption
      • Induce neutrophil chemotaxis
      • Increase vascular permeability and dilation
    • Matrix Metalloproteinases (MMPs):
      • Degrade connective tissue, contributing to tissue destruction

    Factors Contributing to Periodontitis Initiation

    • Disturbance of the equilibrium between dental plaque and host defenses favor tissue damage.
    • Contributing factors include:
      • Increased plaque accumulation
      • Increased pathogenicity of microorganisms in the biofilm
      • Compromised host defenses

    Theories on the Role of Bacteria in Periodontitis

    • Non-specific Plaque Hypothesis:
      • Plaque biofilm accumulation leads to inflammation and tissue destruction.
      • Issues: Simplistic, does not explain all cases, does not account for specific pathogenicity.
    • Specific Plaque Hypothesis:
      • Specific bacteria, rather than total plaque amount, cause periodontal disease.
      • Supporting evidence: Identification of specific periodontal pathogens and their virulence factors.
    • Keystone Pathogen-Host Response Hypothesis:
      • Specific ("keystone") pathogens disrupt the microbiome, leading to a dysbiotic state and enhanced inflammatory response.
      • Issues: Identifying specific keystone pathogens remains challenging.
      • Supporting evidence: Microbiome studies demonstrating changes in bacterial populations and inflammatory responses in periodontitis.

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    Pathogenesis of Periodontal Disease 1 Workbook PDF

    Description

    Test your knowledge on periodontitis, dental plaque biofilm, and the tissues of the periodontium. This quiz covers essential topics, including the stages of biofilm formation and the structure of gingival epithelium. Get ready to dive deep into periodontal health!

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