Aetiology and Pathogenesis of Periodontal Disease

Question 1

What does healthy gingiva look like?

Answer 1

• Knife edge, scalloped gingival margin
• Stippling (in about 30%)
• Pink

Question 2

What disease symptoms does healthy gingiva lack?

Answer 2

absence of bleeding on probing, erythema and edema, patient symptoms, and attachment and bone loss.

Question 3

What are the physiological bone levels value?

Answer 3

range from 1 - 3mm apical to the cemento-enamel junction

Question 4

What is the normal sulcus depth for probing in healthy gingiva?

Answer 4

1-3mm

Question 5

What is gingival health defined as?

Answer 5

< 10% bleeding sites with probing depths ≤3 mm.

Question 6

What are the local plaque retention factors that increase gingivitis?

Answer 6

Calculus
Restoration Margins
Crowding
Mouth Breathing

Question 7

What are the systemic modifying factors that increase gingivitis?

Answer 7

Sex Hormones
Medication

Question 8

What immune cell is abundant in gingivitis?

Answer 8

neutrophils

Question 9

What is the difference between gingivitis and periodontitis?

Answer 9

gingivitis is reversible and can progress to periodontitis

periodontitis is irreversible

Question 10

What happens in periodontitis?

Answer 10

inflammation
loss of periodontal attachment

Question 11

What is a true pocket?

Answer 11

loss of attachment

Question 12

What is the normal distance of the bone measured from ACJ?

Answer 12

1-3mm

Question 13

What are the patterns of bone loss?

Answer 13

horizontal
vertical (angular)
furcation

Question 14

What is the zone of destruction?

Answer 14

a zone around plaque that is roughly 2mm and causes resorption of tissues within it

Question 15

What attachment loss is considered rapid progression?

Answer 15

> 2mm over 5 years

Question 16

What is the species called that can cause change in the biome?

Answer 16

keystone pathogen

Question 17

Why can sterile hosts not get periodontitis?

Answer 17

• Periodontitis cannot occur without the presence of bacteria
• Synergistic infection – plaque ecology is important (requires a community existing beforehand)

Question 18

What are the parts of the host immune response?

Answer 18

• Saliva
• Epithelium
• physical barrier
• shedding of cells
• production of inflammatory mediators
• GCF
• Inflammatory and Immune Responses

Question 19

What are MMPS?

Answer 19

Matrix metalloproteinases are a family of zinc and calcium dependent proteolytic enzymes, which include collagenases

Question 20

What degrades matrix in periodontitis?

Answer 20

matrix degradation is largely a result of MMP’s secreted by host inflammatory cells

Question 21

How are osteoclasts activated?

Answer 21

activation of osteoclasts via RANK/RANKL/other cytokines

Question 22

What are the anatomical risk factors for periodontitis?

Answer 22

enamel pearls
grooves
furcations
gingival recession

Question 23

What tooth positions increase risk of periodontitis?

Answer 23

malalignment
crowding
tipping
migration
occlusal forces

Question 24

What are the iatrogenic risk factors?

Answer 24

restoration overhangs
defective crown margins
poorly designed partial dentures
orthodontic appliances

Question 25

What can smoking cause to increase risk of periodontitis?

Answer 25

• Vasoconstriction of gingival vessels and increased gingival keratinisation
• Impaired antibody production
• Depressed numbers of Th lymphocytes
• Impaired PMN function (polymorphnuclear neutrophils)
• Increased production of pro-inflammatory cytokines

Question 26

What are the genetic risks for periodontitis?

Answer 26

• Some gene variants (e.g. polymorphisms in the gene for IL-1) predispose to periodontitis
• There are environment / gene interactions - for example smoking + IL-1 polymorphism increases risk synergistically