Aetiology and Pathogenesis

Question 1

What are the local factors for gingivitis?

Answer 1

• Calculus
• Restoration margins (PRF)
• Crowding
• Mouth breathing

Question 2

What are the systemic modifying factors for gingivitis?

Answer 2

• Sex hormones

- Medication

Question 3

What is the pathogenesis of gingivitis?

Answer 3

1. Altered microbial colonisation
2. Increased flow of GCF
3. Influx of neutrophils, increased lymphocytes and monocytes
4. Plasma cell infiltrate
5. Proliferation and ulceration of epithelium

Question 4

Describe the progression of gingivitis to periodontitis

Answer 4

• Doesn’t always progress (removal of bacteria –> return to health)
• Attachment loss episodic rather continuous
• Different areas in mouth with varying degree of progression
• Slow; 0.05-0.1mm/ year)

Question 5

What are the host response mechanisms to bacterial colonisation in the mouth?

Answer 5

• Saliva
• Epithelium (protective barrier, cell shedding, produced inflamm mediators)
• GCF
• Inflammatory and immune responses

Question 6

What factors make bacteria virulent in the progression of periodontitis?

Answer 6

• Ability to colonise and compete in an ecological niche
• Ability to evade host defenses
  
  • -> degrade host Ig and complement
  • -> produce leucotoxins
  • -> tissue invasion
  • -> inhibit antibody synthesis

Question 7

Describe the pathogenesis of bone destruction

Answer 7

• Host inflammatory cells secrete MMP –> degrades matrix
• Activation of osteoclast activity

MMP = proteolytic enzymes (includes collagenases)

Question 8

What are the risk factors for periodontitis?

Answer 8

• Smoking (vasoconstriction, impair immune)
• Diabetes
• Stress
• Medication
• Systemic disease
• Nutrition
• PRFs
• Genetic
• Socioeconomic status
• Gender