Microbiology of Periodontal Diseases

Question 1

Chronic Periodontitis

Answer 1

Slowly progressing cumulative disease
Diagnosed in adulthood, but may begin early
Sporadic and unpredictable
Detectable only by observing residual damage from previous disease

Question 2

Aggressive Periodontitis

Answer 2

Begins early
Rapidly Progressing
Shows site-specific patterns of destruction in young patients

Question 3

What is the primary defense cells of periodontitis?

Answer 3

Neutrophils in the sulcus

Question 4

What is the role of inflammation in periodontitis?

Answer 4

Host inflammation attempts to keep microbes under control
Does most of the damage
Provides nutrients to the bacteria

Question 5

If periodontal damage doesn’t include the bone, how is it classified?

Answer 5

It is reversible gingivitis

Question 6

If periodontal damage includes the bone, how is it classified?

Answer 6

Irreversible periodontitis

Question 7

What are the three zones of subgingival plaque biofilm?

Answer 7

Unattached plaque
Epithelium attached plaque
Tooth attached plaque

Question 8

What invades the connective tissue and/or epithelium?

Answer 8

Planktonic bacteria released from biofilm

Question 9

Tissue invasive bacteria do what?

Answer 9

Promote inflammation
If they make it close to the bone:
-prolong osteoclastic activity
-block osteoblastic activity
-net result is bone loss

Question 10

How can bacteria subvert host innate immune pathways?

Answer 10

Pathogenic species may subvert host defenses and enable commensals to overgrow or invade

Question 11

What bacterial species are found in the periodontal pocket?

Answer 11

~700 different species
Not all have been cultured
Both gram- and gram+
Anaerobic or microaerophilic
Proteolytic

Question 12

Are invading pathogens true pathogens or commensal pathogens that just overgrow?

Answer 12

We don’t know
Most studies show commensal, but some recent studies suggest pathogens
Some research shows both commensal and pathogenic that work together

Question 13

What species are found consistently in chronic disease based on classic studies?

Answer 13

The “Red Complex”
P. gingivalis
T. forsythia
T. denticola

Question 14

What species are “under some suspicion” based on cultivation studies to cause periodontitis?

Answer 14

P. intermedia
C. rectus
S. noxia
A. actinomycetemcomitans

Question 15

What species is associated with Localized Aggressive Periodontitis?

Answer 15

A. actinomycetemcomitans

Question 16

How are periodontal pathogens transmitted?

Answer 16

We’ve seen similar species betwen spouces and from parents to children - it’s more likely that it’s because they live similar lifestyles, and it’s probably not contageous