Category:

Biofilms and Periodontal Disease

Learning Objectives

After completing this course you’ll be able to:

  1. Define the term biofilm.
  2. Explain the difference between planktonic organisms and biofilm organisms.
  3. Describe how bacteria adhere to a surface.
  4. Discuss how biofilm bacteria communicate with each other.
  5. Explain the difference between primary and secondary colonizers.
  6. Explain the term ‘bridging’ between early and late colonizers.
  7. Discuss the goals of periodontal therapy.
  8. Discuss biofilm resistance to antimicrobial agents and the host immune system.
  9. Discuss the significance of Aggregatibacter actinomycetemcomitans (formerly Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, and Fusobacterium nucleatum as periodontal pathogens.
  10. Describe the effect of periodontal therapy on subgingival microbiota.
  11. Discuss the diversity of antimicrobials used to treat periodontal disease.
  12. Describe the bacterial recolonization of periodontal pockets.
  13. Explain the ramifications of total eradication v. reduction of levels and proportions of periodontal pathogens.
  14. Discuss the future trends in periodontal therapy.

Course Contents

1. The Biofilm Community

  • Biofilm City of Microbes
  • Social Lives of Pathogens and Virulence

2. Adherence of Oral Bacteria

  • Introduction
  • Habitat
  • Adhesins and Receptors
  • Evolution
  • Conclusions

3. Survival Mechanisms of Microbes in Biofilms

  • Introduction
  • Biofilms Defined
  • How Microorganisms form Biofilms
  • Biofilm Examination and Measurement
  • Biofilm Ultrastructure
  • Resistance to Antimicrobial Agents
    1. Delayed Penetration of the Antimicrobial Agent
    2. Altered Growth Rate of Biofilm Organisms
    3. Other Physiological Changes Due to Biofilm Mode of Growth
  • Human Infections Involving Biofilms<
    1. Periodontitis
  • Biofilms on Medical Devices
    1. Dental Unit Water Lines
  • Relationship Between Biofilm Formation and Disease
    1. Detachment of Cells or Cell Aggregates
    2. Production of Endotoxins
    3. Bacterial Biofilm Resistance to the Host Immune System
    4. Provision of a Niche for the Generation of Resistant Organisms
  • Intervention Strategies
    1. Dental Unit Water Lines
      • Specific Treatments Proposed for Dental Unit Water Lines
      • Novel and Unproven Strategies
  • Conclusions

4. Microbial Aspects of Periodontal Biofilm Communities, Development and Treatment

  • Molecular Genetics Analyses of Dental Biofilm Formation
  • Genetic Basis of Horizontal Gene Transfer Among Oral Bacteria
  • Bacterial Interactions and Successions During Plaque Development
  • The Breadth of Bacterial Diversity in the Oral Cavity
  • The Role of Tannerella Forsythia in the Etiology of Periodontitis
  • Current Understanding of the Role of Actinobacillus Actinomycetemcomitans in Aggressive Forms of Periodontitis
  • Effect of Periodontal Treatment on the Subgingival Microbiota
  • Comment

5. Molecular Genetics Analyses of Biofilm Formation in Oral Isolates

  • Introduction
  • Background
  • Streptococci
  • Actinobacillus Actinomycetemcomitans
  • Porphyromonas Gingivalis
  • Intra-and Inter-Species Interactions
  • Conclusions

6. Microbiological Goals of Periodontal Therapy

  • Introduction
  • The Target Species for Periodontal Therapy
  • Heterogeneity in the Subgingival Microbiota
  • Measurement of the Effect of Therapy on the Subgingival Microbiota
  • Sampling Strategy
  • The Preparation and Processing of the Sample
  • Microbiological Technique
  • Expression of Data
  • Presence or Absence of Species Above Selected Thresholds
  • Why Quantify Species in Subgingival Biofilm Samples?
    1. Methods to Quantify Species or Morphotypes
  • Effect of Different Therapies on the Subgingival Microbiota
    1. Supragingival Plaque Removal
  • Scaling and Root Planning
  • Periodontal Surgery
  • Systemically Administered Antibiotics
    1. Amoxicillin Only and Combined with Metronidazole
    2. Other Antibiotic Agents
  • The Impact on Therapy of Organisms Growing in Biofilms
  • Recolonization of Periodontal Pockets
  • Is Elimination of Pathogens the Microbiological Goal of Periodontal Therapy?
  • Microbial Diagnosis as a Guide to Therapeutic Decisions
  • Usefulness of Microbiological Testing
  • Conclusion

7. Future Trends in Therapy

  • Use of Antagonistic Strains to Reduce Adhesion of Periodontal Pathogens
    1. Adhesion to Surfaces
    2. Antagonistic Strains
    3. Conclusion
  • Guiding Periodontal Pocket Recolonization
  • Vaccination To Prevent Alveolar Bone Loss
  • Efficacy of an Antimicrobial Peptide Against Oral Bacteria
  • Controlling Inflammation To Control Periodontitis
    1. Endogenous Resolving Molecules
    2. Resolution Phase of Acute Inflammation
    3. Endogenous Resolving Molecules as Therapeutic Agents
    4. Prevention of Periodontitis
    5. Treatment of Periodontitis
    6. Biofilm and Inflammatory Periodontitis

8. Summary

Glossary
References