Pathogenesis of Periodontal disease

Question 1

Plaque hypothesis

Answer 1

1. Non-specific plaque hypothesis
2. Specific plaque hypothesis
3. Ecological plaque hypothesis

Question 2

Clinically healthy gingiva

Answer 2

1. Shedding of JE cells into sulcus
2. Flow of GCF into sulcus
3. Antibodies in GCF
4. Inflammatory infiltrate (lymphocytes) in JE
5. Intact barrier of JE

Question 3

Two conditions allowing periodontal pathogens to cause disease

Answer 3

1. Colonization of subgingival area

2. Produce factors that will enter directly or indirectly and damage host tissue

Question 4

4 Stages of pathogenesis of periodontal disease

Answer 4

1. Initial lesion
2. Early lesion
3. Established lesion
4. Advanced lesion

Question 5

Initial lesion

Answer 5

Histopathogenesis

1. Dilation of dentogingival plexus bringing more blood to the area
2. Increased permeability of vessels increase protein and fluid exudate Increased flow of GCF
3. GCF washes away bacteria from gingival sulcus
4. Adhesion molecules are expressed on endothelial cells and neutrophils can bind

Immunopathogenesis

3. Complement system is activated through the alternative pathway producing C3a and C5a
4. Complement factors stimulate mast cells resulting in oedema
5. TNF-alpha allows migration of neutrophils
6. Neutrophils release lysosomal content into sulcus causing tissue damage

Question 6

Early lesion

Answer 6

Histopathogenesis

1. Capillary bed of dentogingival plexus open up resulting in Odema and erythema
2. Neutrophils dominate the inflammatory infiltrate in CT
3. Basal cells of JE and SE proliferate resulting in the formation of rete ridges
4. Proliferation of junctional epithelium

Immunohistopathogenesis
Dominated by lymphocytes
Destruction of collagen fibres
3. Increased expression of adhesion molecules (IL-8)
4. Neutrophils dominate in gingival sulcus
5. Lymphocytes dominate in CT

Question 7

Established lesion

Answer 7

Increase in number of plasma cells
Pseudopocket formation due to proliferation of JE
Spontaneous bleeding
Loss of stippling

Question 8

Advanced lesion

Answer 8

True pocket formation 
Spontaneous bleeding
Gingival recession 
Tooth mobility 
Apical migration of JE 
Clinical attachment loss 
Furcations are visble
Vertical or horizontal bone loss

Question 9

Two mediators causing bone loss

Answer 9

1. IL-1β and

2. TNF-α

Question 10

Characteristics of healthy gingiva

Answer 10

1. Colour - coral pink
2. Consistency- firm and resilient
3. Surface texture - Stippling
4. Location - Coronal to CEJ A
5. Contour - Knife edged interdental papillae
6. Size - normal

Question 11

Clinical signs of gingivitis

Answer 11

1. Swollen gums
2. Bleeding on probing
3. Loss of knife-edged interdental papillae
4. Rolled gingival margin
5. Loss of stippling (shiny, smooth)
   Erythematous gingiva
   Pseudo-pocket formation
   Halitosis

Question 12

Distribution of gingivitis

LGDPM

Answer 12

1. Localized
2. Generalized
3. Marginal gingivitis ‘
4. Papillary gingivitis
5. Diffuse gingivitis

Question 13

Aggressive periodontitis

Answer 13

A. actinomycetemcomitans

P. gingivalis

Question 14

Acute Necrotizing gingivitis

Answer 14

Prevotella
Fusobacteria spp
Rothia denticariosa