Plaque Biofilm (FINAL REVIEW) Flashcards
A layer of living organisms that can attach to a solid object:
biofilm
Biofilm is:
- Composed of ____
- Encased within ____
- ____ in content
- Frequently contain ____
- microbial cells
- matrix that acts as a barrier
- diverse
- micro colonies of bacterial cells
Surrounds the bacteria within the plaque biofilm (acts as a barrier)
plaque matrix
The plaque matrix is composed of:
inorganic and organic components that originate from bacteria
The MAJOR components of plaque matrix:
polysaccharides derived from bacterial metabolism of carbs
The MINOR components of plaque matrix:
salivary glycoproteins
List the organic components of biofilm:
- polysaccharides
- proteins
- lipid material
- glycoproteins
- DNA
List the inorganic components of biofilm:
- Calcium
- Phosphorus
- Trace amounts of sodium, potassium & fluoride
non-mineralized; naturally acquired bacterial biofilm that develops on teeth
dental plaque
Dental plaque is a ____ biofilm
multi-species
Sticky colorless film which constantly forms our teeth:
dental plaque
How may dental plaque be removed?
with mechanical force such as brushing or flossing
Supragingival plaque-
- The initial growth occurs:
- The later growth occurs:
- along gingival margins and interdental spaces
- further extension in the coronal direction
What does materia alba consist of?
- salivary proteins
- bacteria
- desquamated epithelial cells
- disintegrating food debris
Plaque that becomes mineralized by calcium and phosphate salts from saliva:
calculus
What components from saliva allow plaque to mineralize?
calcium & phosphate salts
____ plays a major role in periodontitis because it keeps plaque close to gingival tissues and makes it difficult to remove the irritant
calculus
T/F: CALCULUS is NOT the irritant, PLAQUE is
True
Can calculus be removed with a toothbrush or floss?
No- must be removed professionally
Mineralization of plaque starts in the ____ and eventually occurs within the ____
intercellular matrix; bacterial cells
Calculus is composed of ____ % inorganic components and ___% organic components
70-90% inorganic
10-30% organic
What are the 4 main crystal forms of calculus?
- hydroxyapatite (58%)
- magnesium whitlockite (21%)
- octacalcum phosphate (12%)
- brushite (9%)
Mineralization starts between days ____ of plaque formation
1-14
T/F: All plaque eventually undergoes mineralization
false- all plaque does not undergo mineralizatoin
What are the mineral sources that aid in the mineralization of calculus
supra gingival: saliva
subgingival: GCF and inflammatory exudate
The supra gingival mineral source that aids in the mineralization of calculus:
saliva
The subgingival mineral source that aids in the mineralization of calculus:
GCF and inflammatory exudate
Supragingival calculus is ____ to the gingival margin
coronalS
supragingival calculus is ___ in color
white or yellow
Supragingival calculus derives minerals form:
the saliva
Supragingival calculus is commonly found adjacent to:
salivary gland ducs
Approximately ___% of supra gingival calculus is minberalized
30%
Subgingival calculus is located:
below the crest of marginal gingiva; not clinically visible
What is best for detecting subgingival calculus?
explorer and radiographs
Subgingival calculus derives minerals from:
inflammatory exudate
Describe the color of subgingival calculus:
dense, dark brown or black due to blood components and/or bacterial degredation
Subgingival calculus can be ___ and ___ to the tooth
tenacious and firmly attached
what percentage of subgingival calculus is mineralized?
approximately 60%
How does calculus form/ attach to cementum?
- organic pellicle
- mechanical locking into surface irregularities
- close adaptation to gentle depression or sloping mounts of unaltered cementum
- bacterial penetration into cementum surfaces
What are the phases of dental plaque accumulation?
- formation of pellicle on tooth surface
- initial adhesion/attachment of bacteria
- colonization/plaque maturation
Put the following phases of dental plaque accumulation in order:
- initial adhesion/attachment of bacteria
- colonization/plaque maturation
- formation of pellicle on tooth surface
- formation of pellicle on tooth surface
- initial adhesion/attachment of bacteria
- colonization/plaque maturation
The formation of an acquired pellicle origination from the:
saliva
Within how long from being removed does an acquired pellicle begin to form?
within 1 min
The acquired pellicle is ____ in nature and consists primarily of ___
acellular; glycoproteins
Colonization of the acquired pellicle serves as a ___ for bacteria
nutrient
It takes approximately ____ for the acquired pellicle to develop into its condensed, mature form
7 days
The initial adhesion/attachment of bacteria to the acquired pellicle occurs:
as soon as the bacteria is introduced into the mouth
With the initial adhesion/attachment of bacteria to the acquired pellicle, primary colonizers provide:
binding sites for other bacteria
What are the 3 phases of bacteria colonization onto the acquired pellicle?
- transport to the surface
- initial reversible adhesion
- strong attachment
(TIS the season to colonize to this pellicle)
With maturation of the plaque, ____ occurs because of bacteria attaching to primary colonizing bacteria
coadhesions
With maturation of the plaque, coadhesions lead to growth of:
micro colonies and this, biofilm
List the following steps of plaque formation in order:
- Maturation
- Initial ahdesion
- Pellicle formation
- Dispersion
- Pellicle formation
- Initial adhesion
- Maturation
- Dispersion
List the four functions of the acquired pellicle:
- protection
- lubrication
- nidus for bacteria
- aides in the attachment of calculus
Which of the four functions of the acquired pellicle is being described?
- provides a barrier against acids, thus reducing dental caries attack
Protective
Which of the four functions of the acquired pellicle is being described?
Keeps surfaces moist, prevents drying
lubrications
Which of the four functions of the acquired pellicle is being described?
Key role in development of plaque
Nidus for bacteria
Stage 1 of biofilm formation:
pellicle formation
Stage 2 of biofilm formation:
bacterial colonization
Stage 3 of biofilm formation:
plaque maturation
What stage and day of biofilm formation is gingivitis clincally evident?
Stage 3- Plaque maturation
Days 14-24
The initial colonizers of plaque formation:
gram + aerobic and facultative organisms
(actinomyces & streptococcus)
The secondary colonizers of plaque formation:
P. intermedia
P. gingivalis
Capnocytophaga
Spirochetes
Motile rods
Gram - anaerobic organisms
The secondary colonizers of dental plaque (p. intermedia, p. gingivalis, capnocytophaga, spirochetes, motile rods, and gram - anaerobic organisms are the:
etiologic initiators of caries and periodontitis
Are the initial colonizers or secondary colonizers of bacterial species found in plaque the etiologic initiators of caries and periodontitis?
Secondary colonizers
When energy sources are introduce (sucrose) to the microorganisms in the plaque biofilm, the microorganisms produce:
- Acid
- Intracellular polysaccharides
- Extracellular polysaccharides
Factors affecting plaque accumulation:
- mechanical removal
- availability of nutrients
- undisturbed environment
- interaction between bacteria and host immune response
T/F: Organisms in biofilm are 100x more resistant to antibiotics
false- 1000-1500x more resistant
What makes the bacterial species in a biolfim less susceptible to antibiotics?
slower rate of growth of bacterial species
How long does it take before plaque is clinically visible
days (2)
T/F: Dental plaque is NOT a derivative of food debris
true
Summary:
- Plaque cannot be removed by spraying water
- As plaque matures, it becomes resistant to mechanical removal
- Biofilm forms in 3 stages and matures within 14-24 days
- As bacteria search for nutrients, they migrate sub gingivally
- Host defends itself via inflammatory response; gingivitis is initiated
