Lecture 11 & 12 Flashcards
1
Q
Biofilm is made of a ___ matrix
A
polymeric
2
Q
TF? Biofilm can adhere to both inert or living surfaces.
A
T
3
Q
TF? All bacteria live in biofilm.
A
F. most
4
Q
premedication is important for:
A
arificial heart valve, prosthetic limb, etc., , bacteria attach and grow, leading to failure and death
5
Q
Why not just medicate IF colonization happens, instead of premedicating?
A
Much harder to break down after colonization
6
Q
TF? Bacteria are methanogenic.
A
T
7
Q
Benefit to bacteria of living in biofilm:
A
provides protection against environmental stressors
8
Q
Bacteria found in biofilm is __ times more resistant to antibiotics than free bacteria.
A
1000
9
Q
Biofilm growth sites:
A
hot tubs, ships, cooling pipes of power plant, oil pipelines
10
Q
Biofilms on heart valves cause:
A
Endocarditis
11
Q
Site of pseudomonas biofilm growth in IC people?
A
Alveoli
12
Q
This bacteria can grow on tampons:
A
Strep
13
Q
What bacteria grows in the biofilm of IC ppl?
A
pseudomonas
14
Q
This bacteria can cause toxic shock:
A
Streptococci
15
Q
___% of all infections in developed countries caused by biofilms:
A
65
16
Q
Most common forms of oral disease:
A
Dental Caries and Periodontal Disease
17
Q
The most common forms of oral disease are caused by:
A
Oral Biofilms
18
Q
Steps in biofilm formation:
A
attachment, EPS and “irreversible” attachment, growth and maturation, dispersion of planktonic bacteria
19
Q
Which is more similar to oral biofilm, coral reef or yogurt?
A
yogurt
20
Q
TF Biofilms are homogenous.
A
F
21
Q
How does water flow through biofilms?
A
channels
22
Q
Fxn of water in biofilm:
A
Clear waste, bring nutrients, bacterial growth
23
Q
bacteria in biofilm talk to each other via:
A
quorum sensing
24
Q
This is a type of decision making process in bioilm:
A
quorum sensing
25
Quorum sensing:
decision-making process in biofilms, work together, more virulent, coordinate gene expression, form a multicellular organism, send signals and produce pathogenic molecules
26
TF? Biofilm is hard to kill with chlorhexidine.
T
27
What prevents the rinse from entering the biofilm to get to bacteria?
Matrix
28
Biofilms protect bacteria from both:
antiseptics and antimicrobials
29
Biofilm matrix:
restricts penetration of, and binds antimicrobials, reduces effective concentration, impairs phagocytic cells
30
TF? Free-living bacteria are harder to kill than bacteria in biofilm.
F. Bacteria in biofilm are harder to kill (100-1000 times harder)
31
How are bacteria id’ed in plaque and how many have been found?
nucleic acid technology, about 1000
32
Oral Biofilm is aka:
Dental plaque, sessile microbial communities, structured, yellow-grayish
33
All free-floating bacteria are:
planktonic
34
Does plaque develop on hard or soft tissue?
either
35
What is dental plaque made of?
Living and non living bacteria, their products, and salivary compounds
36
Dental plaque adheres stronger to (hard/soft) tissues
hard
37
TF? All bacteria in dental plaque are alive.
F. some alive, some dead
38
Primary colonizer of heart valve:
strep
39
Composition of dental plaque:
Microorganisms in bacterial polysaccharide matrix and salivary glycoproteins, sticky, impossible to remove by rinsing
40
There are more than ___ different bacterial species
| in dental plaque.
800
41
How many bacteria are there per milligram wet weight in dental plaque?
>10^10 (10 billion)
42
What, besides bacteria, is in dental plaque?
viruses, protozoa, yeast, and ameobas
43
Plaque Dry Weight:
70-80 % bacteria, 20-30 % intercellular matrix
44
The intercellular matrix of plaque is mainly:
bacterial products (glucans)
45
What are bacterial products?
glucans
46
TF? The composition of dental plaque is the same, whether it is sub- or supragingival.
F.
47
How does dental plaque differ in the mouth?
surpragingival vs. subgingival, healthy (ask, healthy plaque? Aerobic bacteria?) vs. diseased, different types of diseased tissues
48
What is the matrix of plaque composed of?
extracellular polysaccharide
49
TF? Materia alba is easily rinsed or sprayed away.
T
50
What is materia alba?
soft accumulations of bacteria and other material
51
What is calculus?
hard deposits
| mineralized, plaque covered by plaque
52
Materia alba is (soft/hard), whereas calculus is (soft/hard).
soft, hard
53
TF? Supragingval plaque is associated with caries, but not gingivitis.
F. both
54
Different Kinds of Supragingival Plaque:
fissure, smooth surface, approximal
55
Where is fissure plaque found?
mainly in molar fissures
56
Where is msooth surface plaque found?
buccal and palatal surfaces
57
Where is approximal plaque found?
contact points of teeth
58
TF? All supragingival plaque produce acid and can lead to decalicification.
T
59
TF? Caries cause more plaque to accumulate.
T
60
When will improving OH alone not be sufficient to reduce the severity of gingivitis?
Many caries along the crevice
61
How long does the initial colonization take in the formation of dental plaque?
1-2 hours
62
What type of organisms are involved in the initial colonization in the formation of dental plaque?
aerobes, generally non-pathogenic, gram positive cocci and rods
63
List 3 early colonizeres:
S. sanguis, S. mutans, Act. viscosus
64
Is the attachment in the initial colonization reversible or irreversible?
reversible
65
Which attachment is irreversible.
the secondary, strong attachment
66
Which is stronger, the intial or the secondary attachement?
secondary
67
What increases the strength of the attachment in the formation of dental plaque over time?
Initial, weak attachement gets stronger as it produces extracellular matrix that binds them together
68
What type of bacteria are the pioneer species in the formation of dental plaque?
planktonic bacteria, within an hour
69
Are the primary colonizers GENERALLY pathogenic or non-pathogenic.
non-pathogenic
70
TF? Plaque can attach to tooth, epitelial tissue and ct, but not bone.
F. can attach to all of these surfaces or remain unattached
71
Subgingival plaque is associated with:
gingivitis and periodontitis
72
Subgingival plaque lays between the:
tooth and the sulcular / pocket epithelium
73
Plaque against tooth surface has different _____ than that along the epithelial surface.
receptors
74
TF? The bacteria found in deeper pockets is different than bacteria found in shallow pockets.
T
75
Why is supragingival plaque bacteria different than subgingival?
exposed to different nutrients and saliva, subgingival: more blood, less oxygen, more anaerobic
76
Serous fluid leaks out of ______.
crevicular lining
77
What part of hemin does P. gingivalis use?
protoporhorin, reduced oxygen tension, more anaeroebic the deeper the pocket
78
Supragingival plaque mainly thrives on:
polysaccharides, sacchrolytic
79
Will the presence of sugar help P. gingivalis to grow?
No
80
What are produced in deep pockets?
Proteolytic enzymes, immunoglobins cleave via proteases and use peptides for growth
81
Where does plaque formation start?
gingival margin and interdental spaces, areas protected against shear forces
82
In which direction does plaque formation extend?
coronally (ask, why do we specify coronally? It extends into the sulcus (apically) as well, right?)
83
Stages of Dental Plaque Formation:
deposition of pellicle, initial bacterial colonization, late bacterial colonization, maturation (DILM)
84
Via what structures do bacteria bind to other bacteria?
Pili, fibria (receptors), or lipopolysaccharide sugars
85
What is the first step in the formation of dental plaque?
deposition of pellicle
86
What is pellicle?
salivary glycoproteins, thin, microscopic coating of (ask, only the first, thin layer of plaque?)
87
How long does it take for pellicle to absorb to enamel?
seconds (we always have a pellicle layer on our teeth, R?)
88
What type of film is the pellicle?
conditioning film, amorphous, acellular
89
What is the second step in the formation of dental plaque?
initial colonization
90
Mechanisms of bacterial attachment:
hydrophobic interaction, calcium bridging (divalent ion), extracellular polysaccharide, surface appendages (Fimbria will bind sugars on proteins via adhesins)
91
calcium + bacteria may lead to:
clumping
92
To which portion of the tooth will bacterial attachment take place?
mineralized portion (? because Ca or P is required?) is this always via divalent calcium interaction?) ask
93
What is the third step in the formation of dental plaque?
late bacterial colonization
94
Late Bacterial Colonization:
Gram-positives multiply, secondary colonizers (ask, are all secondary colonoizers gram negative? yes) attach and multiply, subgingival colonization starts
95
When do secondary colonizers attach?
1-3 days later
96
To what do the secondary colonizers attach?
gram-positive species
97
TF? Secondary colonizers can also be primary colonizers.
F.
98
What type of bacteria are secondary colonizers?
Gram-negative cocci and rods, facultative and obligate anaerobes (pattern to attachment? Facultative first, closer to oxygen? Ask)
99
3 examples of secondary colonizers:
Fusobacterium nucleatum, Prevotella intermedia, Capnocytophaga species
100
What is the primary etiology for periodontal diseases?
subgingival colonization of dental plaque
101
What is the fourth step in the formation of dental plaque?
maturation
102
Maturation step in the formation of dental plaque:
increased plaque, tertiary colonizers, complex structure (i.e. Corn cob)
103
What type of bacteria are tertiary colonizers?
Gram negative bacteria
104
5 examples of tertiary colonizers in the formation of dental plaque:
Porphyromonas gingivalis, Campylobacter rectus, Eikenella corrodens, Aggregatibacter, actinomycetemcomitans, Oral spirochetes (should this include the red complex? denticola, forsythus, P. gingivalis?)
105
spirochetes are:
mobile bacteria
106
In which step of dental plaque formation do corn cob bacteria appear?
Step 4: maturation, "test-tube brushes" or "corn-cob" adherence of cocci to filaments
107
Timeline for dental plaque development:
0-2 days: thin biofilm, easily disrupted, 2-4 days: increase mass, 4-7 days: goes subgingivally, 7-11 days: increase diversity, 21+ days: biofilm mass - relative stability
108
Bacterial shifts in dental plaque formation:
Gram-positive cocci and rods --> Gram-negative cocci and rods -->
Filaments, fusobacteria, spirils and spirochaetes
109
What surrounds fluid channels of plaque?
bacterial microcolonies, intermicrobial matrix, and pellicle
110
Bacteria are surrounded by:
intercellular matrix
111
What is the intercellular matrix composed of?
Polysaccharides from bacterial metabolism
112
Minor components of intercellular matrix:
Salivary and serum proteins/glycoproteins
113
TF? The type of food consumed affects the type of bacteria present in the oral cavity.
T
114
Bacterial metabolism leads to the formation of:
polysaccharides
115
What complexes are mainly associated with peio disease?
Red and Orange Complex
116
Red complex bacteria:
P. gingivalis, T. forsythensis, T. denticola
117
Orange complex bacteria:
P. intermedia, nigrescens, and micros, F nuc. vincentii, nucleatum, polymorphum, and periodonticum, Outer: C. gracilis, C. rectus, E. nodatum, C. showae, S. consellatus
118
TF? Bacteria act as individual species
F. as microbial complexes
119
TF? Bacteria act as microbial complexes.
T
120
TF? Plaque causes gingivitis.
T
121
3 hypotheses related to plaque and oral disease:
non-specific, specific, and ecological plaque hypotheses
122
non-specific plaque hypothesis:
disease results from masses of plaque bacteria, "dirty mouth"
123
"Specific plaque hypothesis":
disease results from certain species of plaque bacteria
124
"Ecological plaque hypothesis":
changes in the environment "turn on" plaque bacteria to become ‘pathogenic’, no specific etiology, dynamic relationship between host and microbiota, increase biofilm, increase inflammatory response, alters local environment, selecting for more proteolytic microbes that lead to greater inflammation
125
Theories as to why stress can lead to more PD:
more steroids in body, not brushing as well due to stress
126
Tx for ecological plaque hypothesis:
remove biofilm and interfere with selective pressures
127
Effects of Metronidozol:
kills more anaerobic, gram negative than aerobic, gram positive
128
TF? Listerine and chlorhexidine kill bacteria non-selectively.
T
129
Therapeutic Implications for Plaque Hypotheses:
"Non-specific plaque hypothesis": oral hygiene, "Specific plaque hypothesis": antibiotics, vaccines, "Ecological plaque hypothesis": diet, buffers, chelators, oxygen (environmental approaches)
130
Host defenses that influence oral microbiota:
temp, atmosphere, pH, genetics, health, lifestyle, receptors, nutrients, host defenses, microbial interactions
131
What does high crevicular fluid result in?
more food for proteolytic bacteria
132
Is there more or less tissue turnover with strong inflammation?
more
133
Will there be more bleeding with low or high gingival crevicular fluid (GCF) flow?
high
134
Will there be a low Eh, a raised pH and C with low or high gingival crevicular fluid (GCF) flow?
low
135
TF? The obligatory anaerobic biofilm is saccharolytic.
F. proteolytic
136
Most common biofilm diseases are:
periodontal disease and dental caries
137
How to reduce periodontal disease and dental caries
Daily removal of biofilm, periodic professional cleaning, frequency of recalls, determined by professional
138
Name of the explorer:
EXD: 11-12
139
Type of perio probe we use:
Michigan O (University of Michigan probe)
140
What type of calculus is the sickle scaler designed to remove?
supragingival calculus
141
How many straight cutting edges does the sickle scaler have?
2
142
The pointed tip of a sickle scaler:
toe
143
Use this primarily for mesial surfaces:
11/12
144
This can be used for BL and distal surfaces:
13/14
145
These tend to be more angled, 60-70 degree:
Graceys’ (single cutting edge)
146
These have two parallel cutting edges that converge:
curettes
147
Shape of scaler and curette in crossection
triangle, semicircle
148
Shape of the toe of a curette:
rounded
149
Angle of face for the universal curette:
90d to terminal shank
150
TF? The universal curette adapts to all four tooth surfaces
T
151
Angle of face for the area specific curette:
60- to 70-d to terminal shank, 1 cutting edge
152
How many surfaces can be cleaned with an area specific curette?
one
153
Which is is the cutting edge used in instrumentation for a curette?
the lower edge (i.e., the longer outer curved edge)
154
most versatile periodontal instrument:
curette
155
Curettes are designed for:
subgingival areas
156
Area-specific curettes are aka:
Gracey curettes
157
Angle fo the blade for Gracey curettes:
60-70d to the shank
158
Angle of shank in relation to blade for universal curettes:
90d
159
Chisel scaler is used for:
tenacious calculus- cutting edge beveled at 45d
160
Primary objective in sharpening a tool:
70-80 d internal angle of blade
161
Benefits of sharp instruments:
Better calculus removal with fewer strokes, smoother root surfaces, improved tactile sensitivity, requires less lateral pressure, increase control of strokes, and reduce clinician fatigue
162
Proper angle for sharpening:
100 to 110d angle,stone and face of blade
163
True or False? All primary colonized are non pathogenic.
F. Most
164
EPS stands for:
Extracellular polymeric substances
