Oral Micro II Flashcards
1
Q
Bacterial populations adherent to each other and to the surrounding environment (surfaces or interfaces), and enclosed in a Matrix are called what?
A
Biofilms
2
Q
T/F
Maintained bacterial biofilms in the mouth generally cause problems.
A
False
*Normal flora
3
Q
T/F
Biofilms are a complex, cooperating, and competing community
A
True
4
Q
What is the protective matrix made of that surrounds microcolonies of biofilm?
A
CHO
*also secreted ECM
5
Q
The primitive/simple communication system used by microorganisms can be thought of as…
A
Quorum sensing
6
Q
Once a quorum is sensed, a colony turns certain genes on and the biofilm can become _____ to antibiotics.
A
More resistant
7
Q
What is the most conspicuous biofilm in the mouth?
A
Plaque
8
Q
What 2 things happen as plaque increases in thickness?
A
Becomes less permeable to oxygen and saliva
higher conc. of toxic products, acids, inflammatory bacterial components
9
Q
T/F
Plaque alters the environment to promote growth of different species
A
True
10
Q
T/F
Too much plaque can lead to dental caries, which leads to consistent loss of periodontal ligament
A
False
*Intermittent loss
11
Q
Three types of flora:
A
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
Q
T/F
Most Transient Flora causes problems
A
False
*difficult time colonizing
13
Q
T/F
Some Transient Flora contain true pathogens and will cause overt disease.
A
True
14
Q
T/F
The indigenous flora is often site specific and tend to recolonize, and aren’t usually pathogenic at that site
A
True
15
Q
What role of Normal Flora leads to Innate Immunity?
A
Competition
16
Q
The fact that some women carry Staph aureus in their vaginal flora that is benign for them would be an example of…
A
Supplemental flora
*flora that exists in some individuals
17
Q
What is a major bacterial species important for seeding the epithelium (and mouth) at birth?
A
Lactobacillus
candida, etc also colonizes
18
Q
Actinomyces israelii is transmitted _______.
A
Orally
19
Q
When the teeth erupt, new ______ develop.
A
Niches
*4 new niches
20
Q
Initial plaque colonizers must be able to do what?
A
Adhere to teeth
21
Q
Dental plaque ecology becomes relatively stable with the eruption of what teeth?
A
Primary 2nd Molars (around 2 yrs)
22
Q
What bacteria can’t hold onto the hard surface of the teeth?
A
Salivarius
23
Q
Why is competition for a foothold in the mouth fierce for bacteria?
A
Most surfaces have high turnover or are flushed with saliva.
24
Q
What teeth pioneer species (2 species) provide binding sites that other bacteria can secondarily grow on (increasing plaque)?
A
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
