Periodontium in Health: Fight Against Invasion

Question 1

List features of a healthy periodontium:

List features of an unhealthy periodontium:

What is the relevance to BOP?

Answer 1

Healthy: pink, stippled, knife edge margin, papillae exactly fill ID space, no BOP from base of pocket

Unhealthy: red, swollen/inflammed gingiva with loss of knife edge margin, papillae under/over-fill interdental space, loss of stippling, BOP from base of pocket

BOP indicates active disease at that site at that time

Question 2

List some facts of Gingivitis:

List some points regarding Periodontitis:

Answer 2

Gingivitis: primary cause is plaque-induced inflammation

• no LOA
• base of pocket is at/coronal (above) the ACJ
• false pockets

This condition is reversible: no permanent damage

Periodontitis: plaque-induced, can be influenced by smoking/diabetes

• LOA: base of pocket below ACJ i.e. on root surface

LOA measured from ACJ to base of pocket –> true pockets

Condition is irreversible: permenant damage, loss of bone and gingival recession

Question 3

Where does plaque bacteria build up, even in health?

What is the gingival sulcus/crevice?

What is at the base of the gingival sulcus?

What problem does this pose?

Answer 3

Plaque builds up at the gingival margin quickly following OH

Gingival crevice/sulcus: small groove between gingival margin and enamel

At base of sulcus, there is junctional epithelium

Junctional epithelium: contains large spaces between epithelial cells so plaque bacteria and their toxins can leak into the underlying gingival connective tissue causing inflammation

Question 4

What is the concept of physiological immune surveillance?

Answer 4

• always a low level of inflammatory infiltrate (mainly neutrophils and some B cells) in the cinnective tissue underlying junctional epithelium

Symbiotic relationship - good balance between good bacteria and host bacteria maintaining health

Question 5

What is Gingival Crevicular Fluid? (GCF)

How much is secreted in clinical gingival health?

What is the dentogingival plexus?

Answer 5

• a serum-like fluid formed from the post-capillary venules of dentogingival plexus
• very small volume of GCF in health - aroud 0.2microlitres/hour = 1ml per day to saliva

The dentogingival plexus is a dense network of blood vessels in the gingival connective tissue sub-adjacent to junctional epithelium

GCF flows through the junctional epithelium into gingival crevice and into the mouth where it mixes with saliva

Question 6

What are the components of GCF?

Answer 6

• plasma proteins
• defence cells/proteins: neutrophils, antibodies, complement
• growth factors

Question 7

List some host mechanisms to prevent bacterial invasion:

Answer 7

• outward flow of GCF into gingival sulcus (washing effect)
• high turnover of JE cells: any invading bacteria attached to epithelial cells are rapidly shed into gingival sulcus
• killing of micro-organisms by inflammatory and immune cells: neutrophils migrating through JE
• destruction of micro-organisms by immunoglobulins and/or activation of complement
• normal bacterial flora restricts micro=organisms growth