plaque is wack Flashcards
how long until own microbiota is established in the gut of the baby
2 weeks
inside uterus, human fetus is __. once born, it acquires
sterile
microorganisms from all its surroundings
after how many years is the entire human microbiota formed and compromised of very complex bacterial species
2 years
the human body contains _____times more bacteria than human cells
1.3 to 10 times
colonization of the oral cavity starts close to the
time of birth
the number of oral bacteria gradually increases as a result of
exposure to external environmental microbial sources
most bacteria within the human body maintain themselves within their host by
adhering to a surface, including within the oral cavity
organisms can survive in the oropharynx when they adhere to either soft tissues or hard surfaces. otherwise, they may be removed by:
- swallowing, mastication, blowing nose
- tongue and oral hygiene
- wash-out effect of the salivary, nasal, and crevicular fluid outflow
- the active motion of the cilia of the nasal and sinus walls
what are the 6 major ecosystems of the oral cavity
- tonsils
- tongue
- ventral surface of tongue
- sulcus
- saliva
- teeth
thin, slimy film of bacteria that adheres to a surface
biofilm
the biofilm:
the layer of living organisms that can attach to a solid object is composed of:
microbial cells that interact closely with neighboring cells benefitting each other when one organism removes another’s waste products and uses them as an energy source
biofilm is encase within
a matrix that acts as a barrier
this surrounds the bacteria within the plaque biolfilm
plaque matrix
plaque matrix is composed of
inorganic and organic components that originate from the bacteria
major components
and
minor components
of plaque matrix
major: polysaccharides derived from bacterial metabolism of carbohydrates
minor: salivary glycoproteins
the biofilm matrix functions as a
barrier
substances produced by bacteria within the biofilm are retained and concentrated, which fosters
metabolic interactions among the different bacteria
these are commonly found in biolfims which form a primitive circulatory system that removes waste products and brings fresh nutrients to the deeper layers of the film
water channels
inorganic components of biofilm
- calcium
- phosphorus
- trace amounts of sodium, potassium, fluoride
the main source of inorganic components of supragingival plaque is primarily:
saliva
structured, resilient, yellow-grayish substance that adheres tenaciously to intraoral hard surfaces, including removable and fixed restorations
dental plaque
this makes it impossible to remove plaque by rinsing or with use of sprays like water picks
EXM aka dental matrix
the dental plaque is composed of mainly
microorganisms
this plaque is found at or above the gingival margin:
when it is in direct contact with the gingival margin, it is called:
supragingival
marginal plaque
this plaque is found below the gingival margin, between the tooth and the gingival pocket
subgingival plaque
can occur in healthy gums too
- this plaque is prime importance during initiation and development of gingivitis:
- critical in calculus formation and root caries:
- important in destruction that characterizes different forms of periodontitis:
- marginal plaque
- subgingival plaque
- tissue-associated subgingival plaque
soft, white accumulation of bacteria, food matter, and tissue cells
materia alba
can materia alba be displaced by water
yes (like water pick)
where is materia alba seen most in
elderly
hard deposit that forms via the mineralization of dental plaque and generally covered by a layer of unmineralized plaque
calculus
how does biofilm become mineralized
by calcium and phosphate salts from salivausually between 1 and 14 day of plaque formation)
does all plaque go under calcification
no
what is the primary source for supragingival plaque?
subgingival plaque?
supra: saliva
sub: gingival crevicular fluid
is plaque or calculus the problem
plaque!
what plays a major role in periodontitis because it keeps plaque close to gingival tissues and makes it difficult to remove the irritant (plaque)
calculus
how is calculus removed
professionally with periodontal instrument
formation can be accelerated by factors such as
smoking and mouth breathing
how to see supragingival calculus if cant tell
blow air!!!
what color is supragingival calculus
yellow or white
where is supragingial calculus commonly found
adjacent to salivary gland ducts
**lingual aspects of lower anteriors
**buccal surfaces of 3 and 14
% mineralized of supragingival calculus :
% mineralized of subgingival calculus
supra: 30%
sub: 60%
how to detect subgingival calculus
explorer and radiographs
this derives minerals from inflammatory exudate (on top of gingival crevicular fluid
subgingival calculus
color of subgingival calc? and why
dense, dark brown or black
due to blood components and/or bacterial degradation
what calc is tenacious and firmly attached to tooth
doesnt want to come off
subgingival calc
plaque attaches to what kind of surfaces
-rough
-surface irregularities on enamel and cementum
-areas of demineralization
calculus attaches on cementum on:
- organic pellicle
- mechanical locking into surface irregularities
- close adaption to gentle depression or sloping mounts of unaltered cementum
- bacterial penetration into cementum surfaces
what are the 3 phases of dental plaque accumulation
- formation of pellicle on tooth surfaces
- initial adhesion/attachment of bacteria
- colonization/plaque maturation
where does pellicle originate from?
saliva
this is a thin-protein-based structureless membrane
pellicle
pellicle can be detected on clean enamel surface within _______ after their introduction into the mouth
1 minute
this is acellular in nature and consists primarily of glycoproteins
pellicle
colonization of ____serves as a nutrient for bacteria
pellicle
how long does it take for the pellicle to develop into its condensed mature structure
7 days
bacteria that adhere to the tooth surface do not contact the enamel directly, but interact with the aquired
enamel pellicle
transmission electron microscopy shows that pellicle is composed of two layers:
- thin basal layers that is very difficult to remove even with harsh chemical and mechanical treatments
- thicker globular layer that is easier to detach
dental enamel is permanently covered with this from the moment that teeth erupt
acquired pellicle
what are the 4 significances of pellicle
- protective: provides barrier against acids, thus reducing dental caries attack
- lubrication: keeps surface moist, prevents drying
- nidus for bacteria: key role in development of plaque
- aides in the attachment of calc
what are the 3 phases of colonization for the initial adhesion/attachment of bacteria
- transport to the surface
- initial reversible adhesion
- strong attachment
the primary colonizing bacteria adhered to the tooth surface provides new receptors for attachment by other bacteria as part of a process known as
cohesion
together with the growth of adherent microorganisms, coadhesion leads to the development of ____and eventually to a mature biolfilm
microcolonies
biofilm maturation is a highly specific event that involves a nonrandom aggregation of
different bacteria
_____do not initially colonize clean tooth surfaces but rather adhere to bacteria that are already in the plaque mass.
the transition from early supragingival dental plaque to mature plaque growing below the gingival margin involes a shift in the microbial population from primarily ______organisms to high number of _____bacteria
secondary colonizers
gram-positive
gram-negative
dental plaque formation quick steps
1
2
3
4
- acquired pellicle formation
- reversible adhesion to pellicle
- irreversible attachment, coadhesion and coaggregation
- biofilm maturation and detachment
biofilm formation timeline
stage 1- pellicle formation
stage 2- bacterial colonization
stage 3- plaque maturation
explain each step of stage 2- bacterial colonization for biofilm formation
day 1
day 2-4
day 4-7
day 7-14
1- gram + cocci
2-4- filamentous forms grow on cocci; intracellular matrix forms and connects colonies
4-7- filamentous forms increases; rods and fusobacteria appear
7-14- vibrios and spirochetes appear; gram - increases; clinical inflammation visible
explain each step of stage 3- plaque maturation for biolfim formation
day 14-24
gingivitis clinically evident
biofilm well established
what initial colonziers of bacterial species are found in plaque
gram + aerobic and faculative organisms (actinomyces, streptocuccus) attached to pellicle
this is approx 47-85% cocci during first 4 hours
gram + aerobic
most abundant colonization occurs on what surfaces
proximal surfaces, fissures, and gingival sulcus BLMD
what secondary colonizers of bacterial species are found in plaque
gram - anaerobic organisms
P. intermedia, P. gingivalis, capnocytophage species, spirochetes, motile rods
-don’t require as much oxygen to survive
these colonizers are the etiologic initiators of caries and periodontitis
gram - anaerobic organisms
P. intermedia, P. gingivalis, capnocytophage species, spirochetes, motile rods
when energy sources are introduced (sucrose) microorganisms produce:
-acid
-intracellular polysaccharides (reverse energy source)
-extracellular polysaccharides (glucans[dextrans] and fructans[levans]
viscous, sticky substances that anchor bacteria to pellicle and stabilize plaque mass:
this is the energy source for dental plaque
glucans (dextrans)
fructans (levans)
plaque organisms adapt to adverse conditions including:
these conditions affect the prolonged existence of the biofilm
pH, temp, ionic strength, absence of nutrients, competing organisms, and inflammatory/immune response
these factors affect plaque accumulation
-mechanical removal (forces from mastication, brushing, tongue movement)
-availability of nutrients
-undisturbed environment
-interaction between bacteria and host immune response
organisms in biofilm (are/are not) 1000-1500 times more resistant to antibiotics
are
biofilm matrix has properties that _____antibiotic penetration
slowdown
____rate of growth of bacterial species makes them less susceptible to antibiotics
slower
this is rapidly liquefied by bacterial enzymes and cleared from the mouth by salivary flow/muscles of mastification
food debris
liquid- cleared within 15 minutes
food- more than an hour
is dental plaque a derivative of food debris
no
can plaque be removed by spraying water
no
as plaque matures, it becomes resistant to
mechanical removal
as bacteria search for nutrients, they migrate
sub gingivally
