Periodontitis

Question 1

periodontal disease

Answer 1

a group of distinct clinical entities that affect the periodontium, including the gingiva, gingival attachment, periodontal ligament, cementum and alveolar bone
include gingivitis and periodontitis

Question 2

gingival crevice

Answer 2

different surfaces for biofilm to form - hard surface (tooth), soft tissue (epithelium)
exposed to the outside environment
low oxygen penetration
close apposition to immune cels
bathed in GCF - high protein

Question 3

periodontal pockets

Answer 3

a distinct environment
anaerobic, with slightly alkaline pH
generally gram+ next to tooth and gram- interacting with the epithelium

Question 4

progression of periodontitis

Answer 4

biofilm accumulation –> change in microbial composition –> chronic inflammation –> alveolar bone loss

Question 5

change in any factor can influence the others such as

Answer 5

more plaque
failure of immune response
localized injury/inflammation increasing GCF flow

Question 6

acquired periodontists

Answer 6

manifestation of systemic disease
neutropenia, leukaemia
genetic disorders
metabolic disorders

Question 7

changing composition of subgingival microbiome

Answer 7

progressive increase in anaerobic environment
lower redox potential in the gingival crevice
increase in GCF flow, slightly alkaline pH
gram-negative rods are dominant species in periodontitis

Question 8

primary pathogen

Answer 8

establish themselves in a niche normally occupied by commensal microbial populations
possess the inherent ability to cross anatomic barriers or overcome other host defenses that limit commensals

Question 9

opportunistic infections

Answer 9

infection when normal host defenses are diminished
can be caused by primary pathogen or normal commensal bacteria

Question 10

periodontal pathogens are all

Answer 10

gram-negative anaerobic bacteria

Question 11

evidence for role in periodontal disease

Answer 11

the organisms are present in diseased sites and their numbers increased with disease
the organisms possess the ability to cause damage to periodontal tissue

Question 12

virulence genes

Answer 12

adherence/colonization factors: fimbriae, capsule
exotoxins
enzymes: proteases, lipases
immune evasion
biofilm formation or survival genes

Question 13

exotoxin in aggressive periodontitis

Answer 13

leukotoxinA binds to receptor LFA-1
ATP released from cells
K+ pumped out
K+ efflux stimulates inflammasome formation
inflammasomes are for cleavage and secretion
cells undergo pyroptosis

Question 14

IL-1B

Answer 14

pro-inflammatory and stimulates osteoclasts

Question 15

inflammasomes are required for

Answer 15

cleavage pro-IL-1B and secretion of IL-1B

Question 16

keystone pathogens

Answer 16

microbial species that remodel the microbial community in ways that promote the pathogenesis
drive dysbiosis

Question 17

dysbiosis

Answer 17

an imbalance in the relative abundance of microbial species in an ecosystem or a community that is associated with a disease

Question 18

pathobionts

Answer 18

the resident species that are normally harmless become pathogenic under certain conditions

Question 19

a low-abundance or keystone pathogen can orchestrate a

Answer 19

disease by remodeling the healthy microbiota into a dysbiotic microbiota

Question 20

P. gingivalis as a keystone pathogen

Answer 20

low-level colonization of the periodontium by P. gingivalis
secretes gingipain that cleaves C5
impaired leukocyte killing
dysbiosis due to loss of normal immune surveillance
more inflammation contributing to bone resorption
C5 blockade promotes the clearance of P. gingivalis

Question 21

PAMPs

Answer 21

molecular signatures that are not present in normal mammals
recognized by pattern recognition receptors

Question 22

PAMPs stimulate

Answer 22

an innate immune response, including cytokine and chemokine production

Question 23

neutrophils

Answer 23

short-lived with high turnover rate
early responders
phagocytes
granules contain lytic enzymes antimicrobial peptide
reactive oxygen and nitrogen species generated
can form NETs

Question 24

chronic inflammation causes periodontal damage

Answer 24

neutrophils fail to control dysbiotic microbiota
microbes invade connective tissue and interact with immune cells, dendritic cells, T cells
inflammatory mediators stimulate bone loss
osteoclasts are similar to macrophages