Pathogenesis of Periodontitis 9/16/15 Flashcards
What are the 4 stages in the development of gingivitis and periodontitis?
- Initial lesion = subclinical stage
- Early lesion = clinical early stage of gingivitis
- Established lesion = Chronic gingivitis
- Advanced Lesion = Progression to periodontitis
When does the initial stage occur?
1-4 days after plaque development
What will start to occur in the initial stage?
- 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
Describe the vascular changes in the intial stage and what the significance is…
- 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
_________ indicate inflammatory changes and bacterial colonization.
GCF constitutes
GCF is a ________ or __________.
Plasma transudate (health) or Inflammatory exudate (disease) “its like sewage”
__________ can be used to test GCF volume.
Ninhydrin stain for protein
Describe the cellular events of the initial stage…
- 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
What induces Chemotaxis of PMN’s?
Host factors (ILF-8 and C5a) Molecules released by bacteria (LPS fatty acids)
When does the Early stage occur?
within 4-7 days of plaque development
What occurs during the Early stage?
- Lymphocytes and PMN’s subjacent to JE
- Few plasma cells
- See mostly T-cells
- Fibroblasts undergoing cytopathic alterations
Is the Early stage clinically detectable? What happens in this stage?
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
What occurs during the Established lesion stage?
- 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
In addition to Macropahges and serum proteins, _____, _____ and ____ are present in the Established lesion stage.
T and B cells
Plasma cells
During the Established lesion phase, what do activated T-cells produce?
IL-2, 3, 4, 5, 6, 10 and 13, TNF-alpha and chemotactic substances
During the Established lesion phase, what do the plasma cells produce?
Ig and cytokines (IL-6 and TNF-alpha)
During the Established lesion phase, what so fibroblasts produce?
MMP’s and TIMP’s
What occurs during the Established lesion stage?
- Increased swelling is evident
- Increased fluid exudation, leukocyte migration
- Collagen loss continues as infiltrate expands
- Conversion of JE to PE (pocket epithelium)
How does JE convert to PE?
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
Does apical migration of JE or bone loss occur during the Established lesion stage?
No! not yet….
What occurs during the Advanced lesion stage?
- 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
What are 3 major modifying factors in the development of gingivitis or periodontitis?
Diabetes
Pregnancy, puberty and menopause
Smoking
Why is diabetes a modifying factor in the development of periodontitis?
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.
Diabetics with sever periodontitis have ______ and _____ problems.
Proteinuria and cardiovascular problems
What effects does Diabetes have on oral bacteria?
- Increase in spirochetes in poorly controlled diabetes
- P. Intermedia, C. Rectus, P. Gingivalis in type 2 diabetes
- Capnocytophaga predominance seen in type 1 diabetes.
What effect does diabetes have on the host?
- Chemotaxis is impaired in PMN’s
- Collagenase increase in diabetics
- PMN enzymes, beta gluco
