What are 3 different types of biofilm in the organization of subgingival biofilm?
tooth-surface-attached biofilm
unattached biofilm
epithelium-associated biofilm
subgingival biofilm that is over the pellicle which covers the tooth surface, a layer of packed microorganisms, and is associated with calculus formation, root caries, and root resorption
tooth-surface-attached biofilm
subgingival biofilm that is between the two layers of attached biofilm, has many planktonic, motile, gram-negative organisms, the planktonic 'free-floating' biofilm contains many white blood cells
unattached biofilm
subgingival biofilm that is loosely attached to the pocket epithelium with many gram-negative microorganisms and numerous white blood cells, and from this layer, microorganisms invade the underlying connective tissue
epithelium-associated biofilm
Biofilm is composed of __________ and _________
microorganisms
intermicrobial matrix
Organic and inorganic solids constitute what percent of biofilm?
20%
Water accounts for what percent of microorganisms?
80%
What percent of the solid matter of biofilm is made up of microorganisms?
70-80%
true or false. Composition of biofilm differs among individuals, and as it ages it changes
true
Name 4 inorganic elements in dental biofilm
calcium
phosphate
magnesium
fluoride
Is the concentration of calcium, phosphorus, and magnesium higher in biofilm or saliva? And what transports these minerals during the mineralization and demineralization processes?
biofilm
saliva
Name 3 or the organic components of biofilm
carbohydrates
proteins
small amounts of lipids
What are 4 types of carbohydrates that can be a part of the biofilm composition and contribute to the adherence of microorganisms to eachother and the tooth?
glucans
fructans
levans
dextran (a type of glucan)
supragingival biofilm contains proteins derived from what?
subgingival biofilm contains proteins from what?
saliva
gingival sulcus fluid
Name 4 areas of distribution of biofilm
supragingival
gingival
subgingival
fissure
biofilm is coronal to the gingival margin
supragingival
biofilm forms on the external surfaces of the oral epithelium and attached gingiva
gingival biofilm
biofilm is located between the periodontal attachment and the gingival margin, within the sulcus or pocket
subgingival biofilm
biofilm also develops in pits
fissure biofilm
Where does bioflim occur most frequently and why?
Where does biofilm occur least frequently and why?
proximal surfaces and around gingival third
hard to clean
palatal surface of maxillary teeth
activity of tongue
What are 5 factors that influence biofilm accumulation?
crowded teeth
rough surfaces
difficult to clean
out of occlusion
bacterial multiplication (thickness of it results from constant cell division of bacteria within)
Using direct vision, what type of biofilm is each of the following described?
-translucent and no visivle until disclosed
-extrinsic stains that make it visible, like yellow, green, tocacco
-tooth may appear dull, dingy, with a matted fur-like surface
thin biofilm
stained biofilm
thick biofilm
What are 4 ways to detect biofilm?
direct vision
explorer or probe
disclosing agent
clinical record
In using an explorer or probe to detect biofilm, what type of examination is being done?
tactile examination
true or false. when present, biofilm will adhere to the probe or explorer tip
true
disclosig agent is not to be applied until what?
evaluation of the oral mucosa and gingival color has been recorded
How is biofilm recorded?
by location and extent
slight
moderate
heavy
true or false. Microbial biofilm plays a major role in the initiation and progression of both dental caries and periodontal infections
true
true or false. periodontal diseases and dental caries are infectious transmissible diseases caused by pathogenic microorganisms found in microbial biofilms
true
true or false. biofilm is significant in the formation of dental calculus. calculus is essentially mineralized biofilm
true
true or false. general oral cleanliness depends on the daily removal of dental biofilm deposits, the accumulation of biofilm contributes to an unpleasant personal esthetic appearance as well as to halitosis
true
a disease of the dental calcified structures (enamel, dentin, and cementum) that is characterized by demineralization of the mineral components and dissolution of the organic matrix
dental caries
cariogenic foods + dental biofilm = ___________
acid formation
fill in the blanks for the sequence of caries and biofilm:
acid formation > ___________ > ______________ > dental caries
demineralization
white spot incipient lesion
What are the initial etiologic agents in biofilm?
mutans streptococci (streptococcus mutans and streptococcus sobrinus)
_________bacilli have a significant role in the progression of a carious lesion and mutans streptococci are prominent in the initiation of the carous process
lacto
What are 2 factors that promote the growth of microorganisms in the biofilm?
decreased salivary flow (xerostomia)
increased carbohydrate intake
how soon does acid form when the cariogenic substance is taken into the biofilm?
immediately
What is the normal/neutral pH in the mouth before eating?
6.2-7.0
* it is lower in caries susceptible person and higher in caries resistant person
At what level does the pH need to be when enamel will demineralize?
At what level does the pH need to be when root surface will demineralize?
4.5-5.5
6.0-6.7
The amount of demineralization depends on what?
the length of time and the frequency with which the acid with a pH below the critical pH is in contact with the tooth surface
