Aetiology and Pathogenesis of Periodontitis

Question 1

What is the primary cause of inflammatory periodontal disease?

Answer 1

plaque

Question 2

What are local plaque retentive factors?

Answer 2

Poor restoration margins
Mouth breathing
Calculus
Crowding

Question 3

What are systemic modifying factors related to plaque accumulation?

Answer 3

Medication

Sex hormones

Question 4

What are the characteristics of a healthy gingiva?

Answer 4

Scalloped/knife edged margin 
Stippled appearance 
Pink 
Steady flow of GCF with antibodies 
Small amount of regulated immune cells
Continuous epithelial shedding 
Intact barrier created by junctional epithelium

Question 5

What are the characteristics of a disease gingiva?

Answer 5

Altered microbial colonisation 
Increased GCF flow 
Influx of immune cells 
Proliferation and ulceration of the gingiva 
Vessel dilation = redness 
Loss of collagen

Question 6

Describe the characteristics of periodontal disease.

Answer 6

Irreversible loss of attachment:

Apical migration of junctional epithelium
Bone loss - presence of more plasma cells (than in gingivitis)

Question 7

What is a true pocket?

Answer 7

Apical migration of the junctional epithelium = loss of attachment

Question 8

What is a false pocket?

Answer 8

Ulceration and proliferation of the gingiva - NO loss of attachment

Question 9

Does gingivitis always progress to periodontitis?

Answer 9

No, if the plaque and plaque retentive features are removed the gingiva should return to health.

Question 10

Describe the type of progression that is involved in periodontitis.

Answer 10

Episodic

Question 11

What is the average loss of attachment per year in periodontitis?

Answer 11

0.05mm to 0.1mm

THIS IS HIGHLY VARIABLE

Question 12

What is the definition of a biofilm?

Answer 12

One or more communities of microorganisms embedded in a glycocalyx which attaches to a solid surfaces

Question 13

Does plaque form a biofilm?

Answer 13

Yes

Question 14

What are the properties of biofilms?

Answer 14

Provides protection
Facilitates nutrient exchange and the removal of waste.
Communicated between bacteria
Establishes the correct physiochemical environment

Question 15

Which bacteria are heavily associated with periodontal disease?

Answer 15

P. Gingivalis
B. forsythus
T. Denticola

Increased numbers are diseased sites
Decreased numbers at sites after receiving periodontal therapy

Question 16

In terms of the immune response, what causes attachment loss via apical migration of the junctional epithelium?

Answer 16

MMPs secreted by host inflammatory cells

Question 17

In terms of the immune response, what causes bone loss?

Answer 17

Osteoclasts

Question 18

What role do neutrophils have in the inflammatory repose of periodontal disease?

Answer 18

Maintains healthy periodontium

Increase in numbers and act as reactive oxygen species to trap and destroy bacteria - fight and contain.

However these reactive oxygen species can also cause harm to the host when there is excessive infiltration in periodontitis = predispose to disease

Question 19

Describe the immune response in an early periodontal lesion.

Answer 19

T lymphocytes initially

B cells and plasma cells enter at a later stage

Antibody is produced locally - prevents the infection from becoming systemic.

Question 20

What are the 3 types of bone loss?

Answer 20

Horizontal - bone CANT be regenerated

Vertical/angular (bone level lower on one side) - bone CAN be regenerated

Furcation

Question 21

Where is horizontal bone loss common?

Answer 21

In narrow alveolar bone

Question 22

What are the general risk factors of periodontitis?

Answer 22

Smoking 
Diabetes 
Nutrition 
Medication 
Systemic disease 
Stress

Question 23

What effect does smoking have on the gingiva?

Answer 23

Increases vasoconstriction of the gingival vessels
Increases keratinisation of the gingiva
Increases pro-inflammatory cytokines
Impairs antibody function

Question 24

What are local risk factors for periodontitis?

Answer 24

Anatomical features:
Enamel projections
Grooves
Furcations 
Gum recession 

Iatrogenic damage 
Restoration overhangs  
Defective crown margins 
Orthodontic appliances 
Poorly adapted RPD

Tooth position 
Crowing 
Malalignment 
Tipping 
Migration