Pathogenesis of Periodontitis 9/16/15

Question 1

What are the 4 stages in the development of gingivitis and periodontitis?

Answer 1

1. Initial lesion = subclinical stage
2. Early lesion = clinical early stage of gingivitis
3. Established lesion = Chronic gingivitis
4. Advanced Lesion = Progression to periodontitis

Question 2

When does the initial stage occur?

Answer 2

1-4 days after plaque development

Question 3

What will start to occur in the initial stage?

Answer 3

• this stage is not detectable clinically
• Early stages of inflammation
• increased permeability
• infiltration of PMN’s and monocytes in the JE
• lymphocytes in the CT
• increased vascular density
• Decreased perivascular collagen
• Increased Gingival crevicular fluid

Question 4

Describe the vascular changes in the intial stage and what the significance is…

Answer 4

• Dilation of vessels in the dentogingival plexus is induced by vasoactive mediators.
• Gaps form between capillary endothelial cells, resulting in increased permeability.
• Fluids and proteins can move out of the capillaries
• GCF flow rate increases

Question 5

_________ indicate inflammatory changes and bacterial colonization.

Answer 5

GCF constitutes

Question 6

GCF is a ________ or __________.

Answer 6

Plasma transudate (health) or Inflammatory exudate (disease) “its like sewage”

Question 7

__________ can be used to test GCF volume.

Answer 7

Ninhydrin stain for protein

Question 8

Describe the cellular events of the initial stage…

Answer 8

• Cytokine mediated up regulation of adhesion molecules on endothelial cells (Vascular)
• PMN’s adhere to post-capillary venues and begin to migrate.
• PMN’s migrate through the JE into gingival sulcus
• Chemotaxis by PMN’s is induced by: Host factors (IL-8, C5a) and molecules released by bacteria

Question 9

What induces Chemotaxis of PMN’s?

Answer 9

Host factors (ILF-8 and C5a)
Molecules released by bacteria (LPS fatty acids)

Question 10

When does the Early stage occur?

Answer 10

within 4-7 days of plaque development

Question 11

What occurs during the Early stage?

Answer 11

• Lymphocytes and PMN’s subjacent to JE
• Few plasma cells
• See mostly T-cells
• Fibroblasts undergoing cytopathic alterations

Question 12

Is the Early stage clinically detectable? What happens in this stage?

Answer 12

Yes!

• Inflammation is clinically visible
• Collagen destruction occurs which creates space for infiltrate
• basal cells of JE and SE proliferate
• epithelial rete pegs invade coronal portion of the lesion
• Dentogeingival plexus remains dilated and is extremely permeable following minor trauma or inflammation.
• A JE invades Ct the previously inactive capillary beds open up and proliferate into the CT Papillae

Question 13

What occurs during the Established lesion stage?

Answer 13

• increased swelling evident (no knife edge appearance)
• increased fluid exudation, leukocyte migration
• Plasma cells increase around blood vessels and in coronal CT
• Collagen loss continues as infiltrate expands to make room for infiltrate

Question 14

In addition to Macropahges and serum proteins, _____, _____ and ____ are present in the Established lesion stage.

Answer 14

T and B cells

Plasma cells

Question 15

During the Established lesion phase, what do activated T-cells produce?

Answer 15

IL-2, 3, 4, 5, 6, 10 and 13, TNF-alpha and chemotactic substances

Question 16

During the Established lesion phase, what do the plasma cells produce?

Answer 16

Ig and cytokines (IL-6 and TNF-alpha)

Question 17

During the Established lesion phase, what so fibroblasts produce?

Answer 17

MMP’s and TIMP’s

Question 18

What occurs during the Established lesion stage?

Answer 18

• Increased swelling is evident
• Increased fluid exudation, leukocyte migration
• Collagen loss continues as infiltrate expands
• Conversion of JE to PE (pocket epithelium)

Question 19

How does JE convert to PE?

Answer 19

The JE and Sulcar Epithelium proliferate and migrate deep into CT, The sulcus deepens and the corneal JE is converted to PE. *PE is loaded with PMN’s

Question 20

Does apical migration of JE or bone loss occur during the Established lesion stage?

Answer 20

No! not yet….

Question 21

What occurs during the Advanced lesion stage?

Answer 21

• similar to established lesion, but switch from T cell to B-cell predominance signals conversion from GINGIVITIS TO PERIODONTITIS!
• Increased proportion of plasma cells (around 50%)
• Destruction of CT attachment to root surface and apical migration of epithelial attachment indicates first clinical sign of periodontitis
• formation of periodontal pocketing and apical migration of JE from CEJ
• Bone destruction begins around communicating blood vessels along crest of septum
• PE is not attached to tooth

Question 22

What are 3 major modifying factors in the development of gingivitis or periodontitis?

Answer 22

Diabetes
Pregnancy, puberty and menopause
Smoking

Question 23

Why is diabetes a modifying factor in the development of periodontitis?

Answer 23

Because incidence and severity of periodontitis is greater in individuals with poorly controlled diabetes.

• Periodontitis increases insulin resistance
• Glycemic control can be improved after periodontal therapy.

Question 24

Diabetics with sever periodontitis have ______ and _____ problems.

Answer 24

Proteinuria and cardiovascular problems

Question 25

What effects does Diabetes have on oral bacteria?

Answer 25

• Increase in spirochetes in poorly controlled diabetes
• P. Intermedia, C. Rectus, P. Gingivalis in type 2 diabetes
• Capnocytophaga predominance seen in type 1 diabetes.

Question 26

What effect does diabetes have on the host?

Answer 26

• Chemotaxis is impaired in PMN’s
• Collagenase increase in diabetics
• PMN enzymes, beta gluco