Week 3 Flashcards
Colonization of the
Oral Cavity:
what happens on day 1?
Starts at birth with facultative and aerobic bacteria
what are potential outcomes of interaction between host and microbe?
infection
colonization
commensalism
disease
death
persistance
what are the 6 major ecosystems in the oral cavity?
hard surfaces : intraoral, supragingival (teeth, restorations)
pocket: periodontal/peri implant pocket
epithelium: buccal epithelium, palatal epithelium, floor of mouth
dorsum of tongue
tonsils
saliva
definition of dental plaque
A structured, resilient, yellow-grayish substance that adheres tenaciously to the intraoral hard surfaces, including removable and fixed restorations
plaque is differentiated from _______ and ______
materia alba
calculus
what does dental plaque look like?
it is primarily composed of:
it is considered to be a ______
it is imposible to remove by:
resilient clear to yellow greyish substance
bacteria in a matrix of salivary glycoproteins and extracellular polysaccharides
biofilm
rinsing or with the use of sprays
3 major phases of plaque formation
- Formation of pellicle on tooth surface
- Initial adhesion and attachment of bacteria
- Colonization and plaque maturation
what are the risk factors for perio disease?
smoking
diabetes
pathogenic bacteria and microbial tooth deposits
what is disease risk?
the probability that an individual will develop a specific disease in a given period
colonization of the oral cavity:
what happens on day 2?
anaerobic bacteria can be detected
colonization of the oral cavity:
what happens on day 14?
mature microbiota is
established in gut of newborn
colonization of the oral cavity:
what happens at age 2?
human microbiota is formed. By this time 1014
microorganisms populate body
after tooth eruption, there is more complex what?
oral flora
are most bacteria commensal and beneficial or harmful?
commensal and beneficial
what does materia alba look like?
it is a soft accumulation of _______, ______, ________, and ________
Is it an organized or disorganized structure?
easily displaced with:
white, cheese like accumulation
salivary proteins, some bacteria, many desquamated epithelial cells, and occasional disintegrating food debris
it is organized and is not as complex as dental plaque
water spray
calculus is a hard deposit that forms via:
generally covered by:
the mineralization of dental plaque
a layer of unmineralized dental plaque
All surfaces of oral cavity are coated with a
_______
pellicle
Within nanoseconds after polishing teeth they
are covered with:
saliva-derived layer =derived
pellicle
Pellicle consists of glycoproteins, proline-rich
proteins, phosphoproteins, histidine-rich proteins, enzymes . . . ______ sites for bacteria
adhesion
initial adhesion and attachment of bacteria:
phase 1:
phase 2:
phase 3:
phase 1: transport to surface/random contact
phase 2: initial adhesion - reversible
phase 3: attachment - firm anchorage
phase 1 and 2 of initial adhesion of bacteria are non ________
specific
phase 3 of initial adhesion and attachment of bacteria depends on specific interactions between _______ cell adhesion molecules and ________ in pellicle
microbial
receptors
what provides hard, non-shedding surface that allows development of extensive structured bacterial deposits
teeth and implants
Teeth are “___________” for
periopathogens
port of entry
Key periodontal pathogens will disappear after:
full mouth extractions
definition of supragingival plaque
marginal plaque when in contact with gingival margin
supra gingival plaque
Gram ________ cocci and _______ predominate at the tooth surface
Gram ______ rods and filaments, spirochetes
predominate at outer surface
positive, short rods
negative
Topography of
supragingival plaque:
Initial growth along _______ and from ______ space
Further extension in ________ direction
Changes with surface _______
gingival margin, interdental
coronal
irregularities
Factors Affecting
Supragingival Dental
Plaque Formation:
rough/smooth surfaces* accumulate and retain more plaque
thicker/thinner plaque has more pathogenicity, more motile organisms, spirochetes, denser packing
Smoothing surface decreases:
rough
thicker
rate of formation
Plaque Formation
Within Dentition:
Forms faster in lower/upper jaw
Forms faster in ______ areas
Forms faster on lingual/buccal surfaces of teeth
Forms faster _______
compared to strict buccal or lingual
lower
molar
buccal
inter proximally
Individual Variables Influencing Plaque Formation:
Rate of formation differs significantly between:
__________ and ________ explain 90% of variation
individuals
Saliva-induced aggregation and relative salivary flow conditions
____ does NOT influence de novo plaque formation
age
plaque in younger/older people led to more gingivitis
older
plaque forms faster adjacent to inflamed or healthy gingiva?
inflamed
plaque is or is not removed spontaneously during eating
is NOT
sub-gingival plaque differs due to:
availability of blood products and anaerobic environment
periodontal pathogens that are strict _____ may contribute little to no initiation of disease
anaerobes
is de novo subgingival plaque formation easy or difficult to completely remove?
difficult
what is the source for recolonization of de novo subgingival plaque formation?
remaining bacteria
some pathogens penetrate _____ tissue and ______
soft
dental tubules
how fast is regrowth of bacteria to pre treatment levels?
within 7 days
Tooth-associated Subgingival
Plaque:
Tooth-associated cervical plaque similar to
_______ plaque
Deeper parts of pocket less _______
Apical portion dominated by smaller/larger organisms without particular _______
supragingival
filamentous
small, orientation
biofilms have an organized/disorganized structure?
organized
in lower layers, the biofilm is bound together by:
polysaccharide
matrix and organic and inorganic materials
_______ run through fluid channels in plaque mass (plaque as biofilm)
nutrients
in plaque as a biofilm, bacterial cells ______ with each other, known as?
communicate
quorum sensing
Bacterial transmission
and translocation:
Are periodontal pathogens and cariogenic bacteria transmissible?
Vertical/horizontal transmission more
frequent than vertical/horizontal in
families
Translocation occurs from 1 niche to another, ie by:
yes
vertical, horizontal
oral hygiene device
non bacterial inhabitants of the oral cavity (4)
viruses
fungi
protozoa
archaea
non specific plaque hypothesis
accumulation of
plaque over time
diminished host response and host susceptibility with age
Plaque control is key to disease control
hypothesis has been discarded, but most therapy is still based on this principle
specific plaque hypothesis
only certain plaque
is pathogenic and this
depends on specific
microorganisms
Major advances in
techniques used to isolate,
identify and sample increased the power of association studies
Unknown whether specific
bacteria cause or correlate
ecological plaque hypothesis
Attempt to unify theories on
plaque and disease.
Both total amount of plaque and specific microbes may contribute to disease.
Site may impact
microbiome.
Host response
may be affected by excessive plaque or host factors (ie smoking, diabetes, diet)
keystone pathogen hypothesis
A specific pathogen present in low abundance that is able to disrupt the periodontal microbiota and lead to dysbiosis
May provide basis for targeted treatment
in health, there is more _________ organisms
in periodontitis there is more _________ organisms
gram +/facultative
gram -/anaerobic
Experimental
gingivitis model:
Early undisturbed plaque
formation follows
___________ growth rate
During first 24 hours, plaque growth is _________- (<3% of vestibular surface)
Next 3 days follow ______ rate
After 4 days growth slows but composition shifts toward _______ and gram ____
exponential
negligible
rapid
anaerobic, gram -
Initial bacteria types associated with gingivitis are: (3)
gram positive rods
gram positive cocci
gram-negative cocci
what are the microorganism types associated with chronic periodontitis? (3)
Spirochetes
anaerobic (90%)
gram – bacteria
(75%)
microorganisms associated with severe periodontitis occurring at an early age:
Bone destruction is extensive in
relation to patient’s age
Almost all localized aggressive harbor A. actinomycetemcomitans
- A.a. may comprise as much as 90% of microbiota
- A.a is primary etiologic agent
what periodontal disease is associated with the stress of HIV infection?
necrotizing periodontal disease
what bacteria are in high levels with necrotizing perio disease?
P intermedia
spirochetes
what is the treatment for necrotizing perio disease?
debridement
OHI
mouth rinse and pain medication
antibiotics as an adjunct if not responsive
what can often occur in untreated periodontitis but can also occur after SRP or during maintenance?
abscesses of the periodontum
can an abscess occur in the absence of periodontitis?
yes (popcorn stuck)
what can occur with an abscess?
pain
swelling
suppuration
BOP
mobility
Microorganisms associated
with periodontitis as a
manifestations of systemic
disease:
Severe destruction may be
associated with mutation of
__________ receptor
_________ and _______ defects
NOT specific ______
Cathepsin C
neutrophil and leukocyte adhesion
microbes
what are the roles of beneficial species of bacteria? (5)
Passively occupy niche
Limit a pathogen’s ability to
adhere to tissue surfaces
Adversely affect growth or
vitality of pathogen
Affect ability of pathogen to
produce virulence factor
Degrade virulence factor
which is more resistant to antibiotics, biofilms or planktonic bacteria?
biofilms
how many more times are biofilms more resistant to antibiotics that planktonic bacteria?
1000-1500
why are biofilms more resistant to antibiotics?
slower growth rate
variations in nutritional
status
pH
prior exposure to antibiotic
resistance to diffusion of antibiotic
what is calculus?
Mineralized bacterial plaque that forms on the surfaces of natural teeth and dental prostheses
Composition of calculus:
______% inorganic:
• 76% _______ _______
• 3% _______ ______
• 4% _______ _________ and other metals
2/3 of inorganic are crystaline (4):
70-90%
calcium phosphate
calcium carbonate
magnesium phosphate
- Hydroxyapatite
- Magnesium whitlockite
- Octocalcium phosphate
- Brushite
Formation of calculus:
Precipitation of mineral salts starts between ____ and ____ day of _______ formation
Calcification can start in as little as __-____ hours
Calcification begins on:
Forms in _____
Initiation and rate vary in _________
1st
14th
plaque
4-8
inner surface of plaque
layers
individuals
what are the 2 theories of mineralization of calculus?
mineral precipitation from local rise in saturation of calcium and phosphate ions
crystal formation of a compound through seeding
what are the 4 modes of attachment to a tooth surface?
1) Via organic pellicle on enamel or cementum
2) Mechanical locking into surface irregularities
3) Close adaptation of calculus undersurface depressions to cementum surface
4) Penetration of calculus bacteria into cementum
where is supragingival calculus located?
located above the gingival margin
where is supragingival calculus heaviest?
near major salivary ducts
where does the mineral source for supragingival calculus come from?
from saliva
what color is supragingival calculus?
white/yellowish
how fast can supragingival calculus from?
less than 24 hours
subgingival calculus is not ______ specific
site
what is the mineral source for subgingival calculus?
GCF and inflammatory infiltrate
where is the highest incidence of subgingival calculus?
proximal surfaces
what color is subgingival calculus?
brown to black
what is the texture of subgingival calculus?
dense, hard, tenacious
is the formation rate of subgingival calculus slower or faster than supragingival calculus?
slower rate
etiological significance of calculus:
Distinguishing between effect of plaque and calculus is easy/difficult
Calculus is always covered with ______
Positive correlation exists between ______ and _______
what is the cornerstone of periodontal therapy?
difficult
plaque
calculus, gingivitis
removal of plaque and calculus
what is disease risk?
the probability that an individual will develop a specific disease in a given period
to be considered a risk factor for periodontitis, the exposure must occur:
exposure can be single point, over multiple points, or continuous
before the disease onset
risk factors for periodontitis may be ______, ______, or _______
environmental
behavioral
biologic
tobacco smoke contains more than ____ known carcinogens
60
what are the 3 main risk factors for periodontitis
tobacco smoking
diabetes
pathogenic bacteria
current smokers are ___ times more likely to have severe periodontitis vs non smokers
3
there is a _____ response relationship between smoking and the prevalence and severity of periodontitis
dose
are the negative effects of smoking on the host reversible or irreversible?
reversible
former smokers respond to periodontal therapy differently or similarly to non smokers?
similarly
how does smoking affect gingival inflammation and bleeding on probing?
it decreases it
- due to decreased gingival blood vessels with increased inflammation
- decreased cervicular fluid flow
to decrease the risk for periodontitis, ______ the number of years since quitting smoking
increase
what are the 5 As when talking to a patient about tobacco?
Ask the patient about smoking status
Advise smokers of the associations between oral disease and smoking
Assess the patient’s interest to attempt to quit
Assist the patient in the attempt
Arrange for referral or follow up visit
what kind of relationship is there between diabetes and periodontitis?
direct relationship
there is/is not a difference between type 1 and 2 diabetes and periodontitis
not a difference
periodontal disease is the ____ complication of diabetes
6th
complications of diabetes
microvascular and macrovascular diseases
Diabetes: level of
glycemic control is
important:
Poorly controlled diabetics:
- Altered _______ function
(PMNs)
- Qualitative changes in
________ - Altered ______ structure
and function - Severe ______ inflammation,
deep _____, rapid _____
loss, and periodontal
______
immune
bacteria
collagen
gingival, pockets, bone, abscesses
Periodontitis in type 1
teenagers ___-fold increased
prevalence in periodontitis
Poorly controlled adult
diabetic ____ times higher
prevalence
OR for smokers with poorly
controlled diabetes: ___ times
Uncontrolled diabetics good/ poor response to therapy relative
to well-controlled and non diabetics
5
- 9
- 6
poor
does the quantity of plaque indicate risk for periodontitis?
it may not indicate risk
the ______ of plaque is important in the risk for periodontitis
composition (quality)
what are some anatomic factors in the mouth that harbor bacterial plaque
furcations
root concavities
grooves
cervical enamel projections
enamel pearls
overhanging margins
calculus
what are the risk determinants/background characteristics for periodontitis? (5)
genetics
age
gender
socioeconomic status
stress
genetic factors for periodontitis:
what alterations are associated with severe periodontitis?
Alterations in ____ genes are one of several
involved in periodontitis
neutrophils and monocytic
hyperresponsiveness
IL-1
Age
Prevalence and severity increase/decrease with age
__________ changes related to aging process
Prolonged _________ over life lead to
cumulative destruction rather than increased rate of destruction
Young/old individuals with periodontal disease are at greater risk for continued disease
increase
degenerative
exposure to other risks
young
who have more attachment loss, men or women?
men
who have higher level of plaque and calculus, men or women?
men
gender differences in prevalence and severity appear to be related to?
preventative practice vs genetic
how does socioeconomic status lead to increased risk of periodontitis?
does socioeconomic status alone lead to increased risk for periodontitis?
decreased dental awareness and decreased frequency of dental visits
no
how does stress lead to increased risk for periodontitis?
increased incidence of ________ during periods of high stress
emotional stress may interfere with normal immune function
necrotizing ulcerative gingivitis
what are 3 risk indicators for periodontitis?
HIV/Aids
osteoporosis
infrequent dental visits
risk indicator: HIV/AIDS
Higher degree of
___________ in
adults with AIDS
Increased periodontal
______ formation and loss of _________
__________ prominent
diagnostic feature
immunosuppression
pocket, attachment
oral lesions
what are oral and periodontal manifestations of HIV infection?
Oral candidiasis
Linear gingival erythema
Oral hairy leukoplakia
Kaposi Sarcoma and other malignancies
Acute necrotizing ulcerative gingivitis
(ANUG)
Necrotizing ulcerative gingivitis and
periodontitis
Chronic periodontitis
how does osteoporosis lead to increased risk for periodontitis?
does osteoporosis initiate periodontitis?
reduced bone mass aggravates periodontal disease progression
no
Risk indicator:
infrequent dental visits
Increased risk for severe periodontitis in patients
who had not visited the dentist for ___ years or more
versus
No more loss of attachment or bone loss in
individuals who did not seek dental care for over ___ years
3
6
what are risk markers/predictors associated with?
do they cause the disease themselves?
examples
associated with increased risk for disease but do not cause the disease
examples: previous history of perio disease
bleeding on probing
previous history of periodontal disease:
severe existing loss of attachment is a predictor for:
no attachment loss of a predictor for:
future loss of attachment
decreased risk for future loss of attachment
Bleeding on probing:
In healthy subjects, % BOP sites has a ______ relationship with probing force
what is a reason for bleeding on probing in the absence of disease?
Reproducibility can be improved by
either ______ or _____
linear
trauma
increasing or decreasing force
