Microbiology

Question 1

Listgarten 1976

Structure of the Microbial Flora Associated with Periodontal Health and Disease in Man: A Light and Electron Microscopic Study

Answer 1

Healthy: primarily gram + coccoids

Gingivitis: more diverse biofilm, supragingival (g+ and G-), subgingival: primarily g-

periodontosis: Electron-dense lobular deposits, gram -

Post-periodontitis: similar to periodontosis

Question 2

Kolenbrander 2000

Answer 2

Early colonizers, F nucleatum (bridging species) and late colonizers

Question 3

F. nucleatum

Kolenbrander 2000

Answer 3

1. most numerous g- species in healthy, #s increase in disease
2. always present when t. denticola and p. gingivalis are present
3. coaggregates with both early and late colonizers
4. late colonizers aggregate with f. nucleatum, but not with each other

Question 4

Red complex

Socransky et al 1998

Answer 4

1. P. gingivalis
2. t. denticola
3. p. forsythia

Question 5

Paster et al 2001

Answer 5

at least 415 species of bacteria in supgingival plaque

Question 6

Dental plaque formation steps

Kolenbrander et al 2002

Answer 6

1. Pellicle formation
2. Attachment of initial colonizers
3. Coaggregation (maturation)

Question 7

Supra vs supg plaque

Answer 7

Question 8

Koch (1890) postulates

Answer 8

A microorganism must
1. must be in abundance in disease
2. be isolated from diseased organism and grown in culture
3. cause disease when introduced in a healthy individual
4. must be reisolated from disease experimental host

Cons: cannot test non-cuiltivatable species, disease caused by multiple species, host response, role of local environment

Question 9

Socransky and Haffajee 1992

Answer 9

Microogranism must:
1. be a viriulent colonal type
2. possess genetic factors that can cause disease
3. host must be susceptible
4. pathogen must be in #s sufficient to cause disease
5. be in right location
6. other species can foster, but not inhibit
7. local environment must allow for existence

Question 10

Polymicrobial synergy and disbiosis

Hajishengallis and Lamont 2012

Answer 10

Periodontitis is caused by a dysbiotic microbiome, synergistic bacteria cause continous, destructive host response

Question 11

Tanner et al 1998

Answer 11

Health: S. Oralis, A. Naeslundii, A. Gerencseriae

Gingivitis: A. Naeslundii, C. Gracilis, T. forsythia

Periodontitis: T. Forsythia, S. noxia, C. rectus

Question 12

Dabdoub et al 2016

Plaque in disease vs. health

Answer 12

Health (no BOP, GI<1, CALoss <1
shallow diseased (CALoss<1, PD<3, GI<1, no BOP)
Deep diseased (BOP, PD>6, CALoss >5, GI>2)

Health: 29% of genes wer for metabolism
75% of bacterial species considered healthy

Shallow diseased: similar to health, but increased dysbiosis

Deep diseased: More bacterial species, red complex, higher archebacteria

Question 13

Layers in NUG

Listgarten 1976

Answer 13

1. Bacterial zone
2. Neutrophil-rich zone
3. Nectrotic zone
4. Spirochetal infiltration zone

Question 14

Etiology of peri-implant disease

Sarmiento et al 2016

Answer 14

1. biofilm
2. iatrogenic factors
3. exogenous irritants
4. absence of KT
5. extrinsic pathology

Question 15

Peri-implant health plaque composition

Hashimoto et al 2022

Answer 15

Lactobacillus and bifidobacterium

Question 16

Peri-implantitis plaque composition

Hashimoto et al 2022

Answer 16

P. gingivalis, t. forsythia, t. denticola, fusobacterium

Question 17

Microbial diversity in periimplantitis vs periodontitis

Answer 17

In general, less species around implants
peri-implant sites contain species not typically seen in periodontitis (Kumar et al 2012) like prevotella, campylobacter, leptotrichia

Mombelli et al 2011 found similar findings^

Question 18

Chronic non-healing wounds

Answer 18

Ganesan et al 2022

peri-implantitis lesions showed:

upregulated genes, thicker biofilms

greater apoptosis, inflammation and chronic cell infiltrate