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Flashcards in Oral Micro II Deck (142):
1

Bacterial populations adherent to each other and to the surrounding environment (surfaces or interfaces), and enclosed in a Matrix are called what?

Biofilms

2

T/F
Maintained bacterial biofilms in the mouth generally cause problems.

False

*Normal flora

3

T/F
Biofilms are a complex, cooperating, and competing community

True

4

What is the protective matrix made of that surrounds microcolonies of biofilm?

CHO

*also secreted ECM

5

The primitive/simple communication system used by microorganisms can be thought of as...

Quorum sensing

6

Once a quorum is sensed, a colony turns certain genes on and the biofilm can become _____ to antibiotics.

More resistant

7

What is the most conspicuous biofilm in the mouth?

Plaque

8

What 2 things happen as plaque increases in thickness?

Becomes less permeable to oxygen and saliva

higher conc. of toxic products, acids, inflammatory bacterial components

9

T/F
Plaque alters the environment to promote growth of different species

True

10

T/F
Too much plaque can lead to dental caries, which leads to consistent loss of periodontal ligament

False

*Intermittent loss

11

Three types of flora:

Normal

Supplemental (minority of pop., generally act like normal flora)

Transient (brought in)

***also, there are Opportunists (part of normal flora that become bad actors when things go wrong)

12

T/F
Most Transient Flora causes problems

False

*difficult time colonizing

13

T/F
Some Transient Flora contain true pathogens and will cause overt disease.

True

14

T/F
The indigenous flora is often site specific and tend to recolonize, and aren't usually pathogenic at that site

True

15

What role of Normal Flora leads to Innate Immunity?

Competition

16

The fact that some women carry Staph aureus in their vaginal flora that is benign for them would be an example of...

Supplemental flora

*flora that exists in some individuals

17

What is a major bacterial species important for seeding the epithelium (and mouth) at birth?

Lactobacillus

(candida, etc also colonizes)

18

Actinomyces israelii is transmitted _______.

Orally

19

When the teeth erupt, new ______ develop.

Niches

*4 new niches

20

Initial plaque colonizers must be able to do what?

Adhere to teeth

21

Dental plaque ecology becomes relatively stable with the eruption of what teeth?

Primary 2nd Molars (around 2 yrs)

22

What bacteria can't hold onto the hard surface of the teeth?

Salivarius

23

Why is competition for a foothold in the mouth fierce for bacteria?

Most surfaces have high turnover or are flushed with saliva.

24

What teeth pioneer species (2 species) provide binding sites that other bacteria can secondarily grow on (increasing plaque)?

S. sanguinis

S. mitis

25

T/F
There is a direct link between the mother's S. mutans and the baby's

True

26

What is generally the 1st pioneer species of the tooth?

What is the second (appearing in pits/fissures around 2 years)?

S. sanguinis

S. mutans

27

Why doesn't S. mutans appear on the teeth until around 2 years?

Doesn't adhere well to smooth surfaces of teeth erupted up until that time

28

What bacteria doesn't appear in the mouth until later in life?

A. viscosus

29

Supragingival plaque contains what 2 G+ bacteria?

Subgingival plaque contains what 2 G- bacteria?

(obviously more are present, these are good examples)

Streptococcus and Actinomyces

Treponema and Fusobacterium

30

T/F
Subgingival bacteria contain mobile forms

True

31

Supragingival metabolic byproducts tend to be _____

Subgingival bacteria always use what as a food source.

Acidic

Protein

**caries caused by acidic environment in supragingival

32

What class of molecules allow Streptococci to be one of the major bacteria in the oral cavity?

Adhesion

*allows Strep to colonize most niches

33

Bacteria tend to grow what direction from the tooth surface?

(these multispecies complexes are held together by linking polymers = Biofilms)

Perpendicular

34

If a biofilm becomes large enough, what no longer works to combat them?

Saliva buffers

35

A complex grouping of various bacteria species that adhere to one another, bacteria products, and salivary proteins.

Plaque Biofilm

36

What did a classic study of poor oral hygiene find correlated with gingivitis?
(general type of bacteria)

Anaerobic forms and rods

*Reversible after 21 days

37

If brushing stops, what increases?

What decreases?

Gram- anaerobes

Gram+ aerobes

38

What occurs as plaque increases in complexity and density?

Food Chains develop

39

What glucose polymers make up a good amount of matrix?

Dextrans

40

What vitamin is associated with periodontal disease?

What does it do?

Vitamin K

Fertilizes G-

41

T/F
Many forms of subgingival bacteria stink

True

42

What is the inflammation of gingival tissues, typically due to plaque build-up?

Gingivitis

43

What 3 things differentiate Gingivitis from Periodontitis?

No irreversible destruction of perio ligament

No bone loss

No apical migration of junctional epithelium

44

T/F
Healthy to Acute to Chronic gingivitis is all reversible

True

45

T/F
Chronic gingivitis to Periodontal disease is reversible

False

46

T/F
Fluctuations in host defense capabilities brought on by stress, drugs, disease, etc, contributes to gingival disease outcome

True

47

T/F
The factors enabling the progression of Gingivitis to Periodontal disease are largely known

False

48

What are the 2 major categories of Periodontal disease?

Chronic

Aggressive

* a third one is associated with Systemic Disease

49

Most periodontis pockets display what?

Climax Community Flora

50

Why do most of us develop chronic gingivitis?

Gingival inflammatory response ensures Bacteria don't invade tissues

*and this is ongoing

51

The key to inducing a bleeding gingivitis is the introduction of what?

One or more G- anaerobic bacteria

*also leads to Periodontitis

52

Initially (before gingivitis), what two species are dominant on supragingival plaque?

What species increases as plaque load grows?
Why?

Strep. and Actino.

Actino.

Actino. is Microaerophilic

53

What organisms need the heme that inflammation provides?

What does this organism produce once it has heme?

Bacteroides

LPS (highly inflammatory type)

***this leads to Bleeding Gingivitis

54

In a very basic sense, the Loe experiment demonstrated what?

When Good bacteria decrease Bad increase

55

Chronic marginal gingivitis is a ________ inflammatory response to supra-gingival plaque

non-specific

56

Who did the experiments that definitively laid out the relationship between oral hygiene, plaque, and progression of gingivitis?

Loe

*also found gingivitis reversible after 21 days

57

What might initiate gingival disease progression?

Interruption of "balance" of normal bacteria/host defense

58

Name 5 factors that influence Gingivitis

Hormonal changes (pregnancy)

Drugs (cyclosporin, Ca channel blockers)

Disease (diabetes)

Stress

Oral Habits (chewing, smoking, mouth breathing, etc)

59

The severity of gingivitis depends on the balance between what?

Plaque bacteria and Immune response to it

60

What is characterized by painful gingival lesion with gray pseudo-membrane that readily sloughs revealing bleeding and necrosis?

NUG - Necrotizing Ulcerative Gingivitis

aka Vincent's Infection

61

What is the onset time of NUG?

Diagnostic shortcut?

Where are the lesions usually found?

Quick

Bad breath

Interdental gingival tips (papillae)

62

What population is NUG found in and why?

Homeless

Stress

***elevated corticosteroids suppress immunity

63

What was a classic case of NUG in history?

Trench Mouth

64

How is NUG different from most bacterial invasions in gingivitis?

What causes the bad breath?
(2 species)

True infection

Treponema spp (G- spirochete)

Prevotella intermedia (G- rod)

(they produce noxious sulfur)

65

T/F
NUG is most often seen in young adults from 16-30 years.
The more severe sub-saharan disease (90% mortality) is called NOMA and causes massive facial damage.
NUG is 70% Gram- Rod

True

66

What are the 3 main zones of a NUG lesion?

Grayish pseudomembrane

Red bleeding necrotic zone

Deeper tissue of tissue being invaded by G-

67

NUG is associated with decreased host immunity, especially in regard to _____.

One of the major causes may be increased levels of ______ in response to stress.

PMN's

Corticosteroids

68

What % of americans have periodontal disease?

What is the most predictive factor?

50%

Age

69

Name 4 factors in Periodontal disease pathology

Microbes

Host Genetics

Oral Environment

Immunology

70

Age, Poverty, Tobacco, Systemic diseases (diabetes), medications, crooked teeth, pregnancy, Red complex bacteria, Heredity, and oral hygiene are all factors in Periodontal disease.

True

71

Two defining results of Periodontal disease.

Periodontal ligament destruction

Irreversible damage

72

T/F
Loss of collagen attachment persists after the active periodontal disease process has ceased

True

73

Can attachment loss indicate if perio disease is ongoing or a result of previous manifestation?

NO

74

Most periodontis is due to what?

Loss over a lifetime

75

T/F
Periodontitis is a polygenetically influenced disease

True

76

Periodontitis could be due to multiple _____ or multiple ______.

disease mechanisms

synergistic factors in susceptible hosts

77

Why is it not clear what specifically causes active periodontal disease?

Bacterial products damage tissue

Inflammatory factors damage tissue

*Imbalance may cause perio disease

78

T/F
An as yet unknown oral organism may be the causative agent in perio disease.

True

*but unlikely

79

T/F
Unique combinations of organisms along with impaired host immunity may cause perio disease

True

80

What are the 3 major hypotheses of Perio Disease?

Specific bacteria

Specific mechanisms, multiple bacteria

Multiple mechanisms, multiple bacteria

81

As far as treatment is concerned, what are the 3 Hypotheses of Perio Disease?

Nonspecific Plaque Hypothesis - all plaque bad (mow lawn)

Specific Plaque Hypothesis - Certain plaque pathogenic

Dysbiosis - Ecological imbalance causes biofilm and disease

82

What does Dysbiosis involve that disproportionally effects environment?

Keystone Pathogens

**may be part of Dysbiosis theory

83

List the 5 major suspected Periodontal pathogens, starting with the 3 that make up the Red Complex.

Porphyromonas gingivalis

Tannerella forsythia

Treponema denticola

Prevotella intermedia

Agregatibacter actinomycetemcomitans

84

Which bacteria is most associated with Chronic perio?

Which bacteria is most associated with Aggressive perio?

Porphyrymonas gingivalis (chronic)

Aggregatibacter a. (aggressive)

85

3 damaging microbe products:

Exoenzymes

Exotoxins

Toxic metabolites (ammonia)

86

Name 2 defense inhibitors deployed by microbes causing Perio disease?

decrease PMN migration

decrease T/B-cell function

87

Type I-IV immune hypersensitivity is kicked off by an unknown antigen in Perio disease. (?)

What is also bad?

True

Hyposensitivity

88

Koch's postulates generally don't work with Periodontitis. What replaced these?

Socransky's postulates

89

What gram stain tends to be good for Perio disease and bad for caries?

G+

90

7 features of Aggregatibacter actinomycetemcomitans:

G- Rod

Caphophilic (loves CO2)

Facultative

Catalase+

pH 7-8, slightly alkaline

Saccharolytic

Increased growth with Steroid Hormones

91

Pound for Pound, A.a. makes what?

More LPS

92

The LPS vesicles (blebs) of A.a. do what 3 things?

LPS activates Macrophage

releases Leukotoxin (cytotoxic exotoxin for PMN's, Macrophage)

Stimulates osteoclasts (via protein)

93

A.a. is found in ___% of ___ in adult periodontitis

A.a. is found in 90% of _______

30-50%, Agressive

Aggressive juvenile Perio (localized)

94

5 features of Porphymonas gingivalis (P.g.)

G- rod

Anaerobic

Needs Hemin

pH 7.5-8.5

Asaccharolytic (protein major food source for G-)

95

Name 5 virulence factors for P.g.

CHO capsule

Toxic products

LPS (much much less inflammatory)

Proteases

Invades/quorum sensing

96

What is a major difference between A.a. and P.g.?

LPS is very stealthy in P.g.

97

In terms of A.a. and P.g., how does Periodontitis change with age?

A.a. dominant when young

P.g. dominant when old

98

Where are A.a. and P.g. found in the mouth?

A.a. - specific sites

P.g. - everywhere

99

P.g. and A.a. are found in what numbers in a healthy mouth?

Small numbers - .005%

100

A.a. is associated with what type of periodontitis?

P.g.?

LAP (localized aggressive perio)

GCP (generalized chronic perio)

101

LAP shows what ethnic bias?

There is a ____ fold difference between European population and African in the US of LAP

(north) African

(and African American in the US)

20 fold

102

T/F
P.g. dodges Antibody complement

True

103

T/F
Oxygen is removed from the sulcus by organic molecules, creating an anaerobic environment.

True

104

The low levels of saliva/food in the sulcus means most bacteria will dine on what?

Protein

105

Because salivary washing isn't much of a factor in the sulcus, what virulence factor is no longer very important?

Adhesion

106

The different surfaces of the gingival sulcus create what?

More complex environment

107

The major function of PMN's in the gingival sulcus is what?

LPS removal

108

What controls the mechanisms of attachment loss in perio?

Th cell direction

109

Why is tooth loss not a bad thing systemically?

Removes the insult

110

What is damaged with increased bacterial penetration into the sulcus?

Junctional epithelium

111

T/F
The role of the large B cell buildup upon bacterial invasion of the junctional epithelium isn't well understood

True

112

IL-1 switches fibroblast function from collagen production to production of what 2 things?
(this is upon bacterial invasion of the junctional epithelium)

Collagenase

PGE2

113

IL-1, TNF-alpha, and PGE2 switches bone repair to what?
(upon bacterial invasion of jct. epi)

Osteoclast activation

114

North Africans have a higher rate of LAP that other populations due to what clone (bp deletion) in what species?

JP2

A.a.

115

The JP2 clone in A.a. is more pathogenic why?

Leukotoxin production maxed

116

T/F
JP2 clone doesn't spread easily to Europeans.

True

117

What is the term for inflammation of the pulp?

Pulpitis

118

Pulp tissue responds to insults with what process?

Inflammatory

119

Why will pulp become quickly necrotic?

Poor collateral circulation

120

What is the most common way for pulp to become infected?

Another way?

Caries

"leaky" restorations

121

What are the initial bugs that make it through the dentin into the pulp?

Lactobacillus

*then taken over by Perio bugs like Pg and Aa

122

In a carious lesion, ______ chops at enamel and ______ is the first to hit the pulp.

Mutans

Lactobacillus

123

Two forms of pulpitis:

Reversible (insult removed)

Irreversible

124

PMN:

Name 3 mononuclear cells:

Neutrophils

Macrophage, T-cells, B-cells (also NK cells)

125

Look for ____ in acute pulp infection and _____ in chronic infection.

*both these cells cause significant damage themselves

PMN's

Macrophage

126

What is the term for microbial leakage out of the root apex and destroying surrounding bone tissue in pulp infection?

Periapical Granuloma

127

Dental pulp is generally free of viruses. What is one exception?

HSV

128

How was the bacterial damage in pulpitis definitively shown?

Germ free animals didn't develop

129

At what point in penetration of the tooth does bacteria reach the pulp?

Once Dentin reached, bacteria can travel down tubules

Infection precedes carie in this way

130

What type of inflammation usually occurs as infection precedes the carie reaching the pulp?

What occurs in Dentin during this process?

Chronic - mononuclear dominated (Macrophage, T/B cells)

Bacteria induce reactionary/reparative dentin

131

The type of pulpal inflammation tissue is capable of recovering from (once noxious stimuli removed) is called?

Reversible pulpitis

*during which time a tooth may be saved

132

Once ______ reaches the pulp, irreversible inflammation sets in.

This defines?

Plaque Bacteria

Irreversible pulpitis

133

T/F
Pulp infections are almost always polymicrobial

True

134

What type of microorganisms dominate infected pulp?
(3)

Subgingival, G-, facultative/anaerobic

135

The G- facultative/anaerobic bacteria infecting pulp is made up of how many species?

10-30

136

What is a G+ bacteria commonly associated with Pulpitis?

Lactobacillus

137

Name 5 G- bacteria commonly associated with Pulpitis

Fusobacterium
Porphyromonas
Prevotella
Tannerella
Treponema

138

The bacteria infecting the root canal mirrors bacteria infecting _____

Periodontal disease

139

What identification problem is the same in Periodontal disease and Root pulp infections?

Instigator bacteria vs. follower bacteria

140

Describe the 2 step treatment course for Infected Dental Pulp.

Mechanical/chemical elimination of Agents

Restoration (unleaky)

141

Bacteria in biofilms can be up to _______ less sensitive to anti-microbial agents.

How is this often achieved?

1000x

Communication (quorum sensing)

*latter may explain the smoldering effect followed by explosion in many infections

142

T/F
Bacteria at the biofilm suggest a periapical tissue lesion is a biofilm disease.

True

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