Aetiology and Pathogenesis of Periodontal Disease

Question 1

What is the definition of gingival health?

Answer 1

Less than 10% BOP with pocket depths less than or equal to 3mm.

Question 2

What are common features found in gingival health?

Answer 2

Knife edged scalloped margin of gingivae
Pink
Stippling- collagen tethers the papilla on the underlying tissues.
Bone levels are 1-3mm apical to the CEJ.
No LOA, no bone loss.

Question 3

Describe the pathogenesis of gingivitis.

Answer 3

Accumulation of plaque at the gingival margin.
Influx and efflux of neutrophils into the gingival crevice, as well as lymphocytes.
Causes the gingiva to become red, puffy, lose it’s knife-edged appearance.
No bone loss or LOA.
If the plaque is removed, the gingivitis will go away and the immune system will calm down.

Question 4

What factors will make gingivitis worse?

Answer 4

Plaque retentive factors- plaque, calculus, overhangs.
Crowding
Mouth breathers
Medication
Sex hormones

Question 5

What is the difference between periodontitis and gingivitis?

Answer 5

Periodontitis has LOA and bone loss.
Pocket depth greater than 3mm.

Question 6

What is a false pocket?

Answer 6

Proliferation of the sulcular epithelium and enlargement of the gingivae due to plaque accumulation.
Probe disappears into the “pocket” but there is no loss of attachment.

Question 7

What is a true pocket?

Answer 7

Apical migration of the sulcular epithelium and the junctional epithelium.
Plaque accumulation on the rooft surface and continues to cause apical migration of the epithelium.
Bone loss occurs as well.

Question 8

What is the difference between horizontal bone loss and vertical bone loss?

Answer 8

Horizontal bone loss occurs when bone is lost in a flattened pattern throughout the arch.
Vertical bone loss occurs when there is thicker bone on one side of the tooth and thinner bone on the other side- 2mm zone of destruction.

Question 9

What is furcation bone loss?

Answer 9

Bone loss around the furcation of a molar tooth.

Question 10

Describe the pathogenesis of periodontitis.

Answer 10

Starts off with gingivitis (as discussed previously).
If plaque is not removed, it starts to move down the surface of the root- causing LOA.
There is a frank dysbiosis of the immune system in periodontitis- causes commensal bacteria to become pathogenic.
This causes even further up-regulation of the immune response- influx of pro-inflamamotry cytokines, lymphocytes.
Failure to resolve inflammation, on-going non-resolving inflammation.
Causes connective tissues and bone damage- dysregulation of OPG:RANKL.

Question 11

What are the keystone pathogens of periodontitis?

Answer 11

Porphyromonas Gingivalis.
T.Forsythia
T.Denticola

Question 12

What factors cause soft tissue destruction and bone loss?

Answer 12

Soft tissue- MMPs.
Bone- RANKL:OPG ratio.

Question 13

Describe some local risk factors for Periodontitis.

Answer 13

Overhangs on restorations
Calculus
Crowding
Defective crown margins
Poorly designed dentures
Orthodontics appliances
Gingival recession

Question 14

Describe some systemic factors for periodontitis.

Answer 14

Smoking
Poorly controlled diabetes
Genetics- IL-1 polymorphism

Question 15

Name some environmental risk factors for periodontitis.

Answer 15

Stress
Local microbiome.

Question 16

Why are smokers at an increased risk of periodontitis?

Answer 16

6 times higher risk of developing periodontitis.

Thought o be caused by a reduced blood flow, impaired white cell function, reduce capacity for wound healing and increased production of pro-inflammatory cytokines, enhancing tissue breakdown.

Question 17

What do smokers usually present with?

Answer 17

• Greater calculus formation
• Higher mean probing pocket depths and more sites with deep pockets
  Greater gingival recession
• Greater alveolar bone loss and furcation involvement
• Less bleeding on probing.

Question 18

How often should MPBS be carried out?

Answer 18

Every appointment

Question 19

What parameters in the MPBS would make the patient engaged?

Answer 19

Less than or equal to 20% plaque
Less than or equal to 30% bleeding

or

50% improvement in both

Question 20

What is marginal bleeding a representation of?

Answer 20

How well the patient is carrying out OH advice.

Question 21

What is BOP?

Answer 21

Inflammation at the base of the pocket.

Question 22

What happens if the patient is not engaged after step 1?

Answer 22

Do not move on to step 2- re do OHI, supra gingival PMPR, determine barriers to improved OH.