Plaque and Other Dental Deposits Flashcards
Within __ weeks, a nearly mature microbiota is established in the gut of a baby
2
After approximately __ years, the entire human microbiota is formed and comprised of very complex bacterial species
2
The human body contains _______ times more bacteria than human cells
1.3 to 10
Colonization of the oral cavity starts…
close to the time of birth
Most bacteria within the human body maintain themselves within their host by…
adhering to a surface, including within the oral cavity
How are organisms removed from the oral cavity?
- Swallowing, mastication, or blowing the nose
- Tongue and oral hygiene implementation
- The wash-out effect of the salivary, nasal, and crevicular fluid outflow
- The active motion of the cilia of the nasal and sinus walls
Most organisms can survive in the oropharynx when they adhere to…
either soft tissues or the hard surfaces
What are the six major ecosystems of the oral cavity?
-tonsils
-tongue
-floor/roof of mouth
-subgingival tissue
-saliva
-crowns, implants, etc.
What is a biofilm in nature?
A thin, slimy film of bacteria that adheres to a surface
What is a biofilm composed of?
microbial cells that interact closely with neighboring cells mutually benefiting each other when one organism removes another’s waste products and uses them as an energy source
What is a biofilm encased in?
matrix that acts as a barrier
What does a plaque matrix do?
Surrounds the bacteria within the plaque biofilm
What is a plaque matrix composed of?
- inorganic and organic components that originate from the bacteria
- Major components: polysaccharides derived from bacterial metabolism of carbs
- Minor components: salivary glycoproteins
Water channels are commonly found in biofilms which form…
primitive circulatory system that removes waste products and brings fresh nutrients to the deeper layers of the film
What are the main inorganic components of biofilm?
- Calcium
- Phosphorus
- Trace amounts of sodium, potassium, fluoride
Main source of inorganic components of supragingival plaque is primarily…
saliva
As the mineral content in saliva increases, the biofilm mass becomes calcified to form…
calculus
What is the definition of dental plaque?
a structured, resilient, yellow-grayish substance that adheres tenaciously to intraoral hard surfaces, including removable and fixed restorations
The extracellular matrix makes it impossible to remove plaque by…
rinsing or with use of sprays
What is dental plaque composed of primarily?
microorganisms
____________ plaque is found at or above the gingival margin
Supragingival
__________ plaque is found below the gingival margin, between the tooth and the gingival pocket
Subgingival
When plaque is in direct contact with the gingival margin, it is called ________ plaque
marginal
Supragingival plaque and tooth-associated subgingival plaque are critical in…
calculus formation and root caries
Tissue-associated subgingival plaque is important in…
the tissue destruction that characterizes different forms of periodontitis
Where is the initial growth of supragingival plaque?
along gingival margins and interdental spaces
- may also originate from grooves, cracks, or pits
Where does plaque growth later?
coronal direction
What is materia alba?
Soft, white, accumulation of bacteria, food matter, and tissue cells
What does materia alba consist of?
salivary proteins, bacteria, desquamated epithelial cells/disintegrating food debris
Is materia alba easily displaced with water spray?
YES
Is plaque easily displaced with water spray?
NO
What patient population generally has materia alba?
older patients
What is calculus?
Hard deposit that forms via the mineralization of dental plaque and that is generally covered by a layer of unmineralized plaque
Biofilm becomes mineralized by _________ and _________ salts from the saliva
calcium and phosphate
Biofilm mineralization usually starts between the ___ and ___ day of plaque formation
1st and 14th
Calcifying plaques may become 50% mineralized in ___ days
2
Calcifying plaques may become 60-90% mineralized in ___ days
12
_______ is the primary source for supragingival calculus formation
Saliva
_________________ provides the minerals for subgingival calculus
gingival crevicular fluid & inflammatory exudate
Why does calculus play a major role in periodontitis?
keeps plaque close to the gingival tissues and makes it difficult to remove the irritant (plaque)
What is the irritant: plaque or calculus?
plaque
How can calculus be removed?
- Cannot be removed with a toothbrush, floss, etc.
- Must be removed professionally with periodontal instrumentation
What can accelerate calculus formation?
smoking and mouth breathing
What are the features of supragingival calculus?
- Coronal to the gingival margin
- White or yellowish in color
- Derives minerals from the saliva
- Commonly found adjacent to salivary gland ducts
- Approximately 30% mineralized
What can you do to see supragingival calculus?
blow air on it
Where is most of the supragingival calculus found?
- lingual of mand anteriors
- buccal of max 1st molars
- adjuacent to salivary gland ducts
What percent of supragingival calculus is mineralized?
30%
What are the features of subgingival calculus?
- Located below the crest of marginal gingiva; not clinically visible
- Explorer and radiographs are best for detecting
- Derives minerals from inflammatory exudate
- Dense, dark brown or black due to blood components and/or bacterial degradation
- Can be tenacious and firmly attached to the tooth
- Approximately 60% mineralized
What is more mineralized: supragingival or subgingival calculus?
SUBgingival
What percent of subgingival calculus is mineralized?
60%
What is subgingival calculus dervied from?
minerals from inflammatory exudate
How can you best detect subgingival calculus?
Explorer and radiographs are best for detecting
What color is subgingival calculus?
Dense, dark brown or black due to blood components and/or bacterial degradation
Where does calculus attach to teeth?
- Surface irregularities on enamel and cementum (cingulum, CEJ, root concavities, furcations)
- Areas of demineralization
- On cementum
Where does calculus attach to the cementum?
- 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 three phases of dental plaque accumulation?
- Formation of pellicle on tooth surface
- Initial adhesion/attachment of bacteria
- Colonization/plaque maturation
Where does the pellicle originate from?
saliva
What is the pellicle?
Thin, protein-based, structureless membrane
Pellicle can be detected on clean enamel surfaces within _____ minute(s) after their introduction into the mouth
one
What is the pellicle primarily made of?
glycoproteins
Pellicle takes approximately __ days for it to develop into its condensed, mature structure
7
Bacteria that adhere to tooth surfaces do not contact the enamel directly, but interact with the acquired enamel…
pellicle
What are the two layers of the pellicle?
- a thin basal layers that is very difficult to remove, even with harsh chemical and mechanical treatments
- a thicker globular layer that is easier to detach
Dental enamel is permanently covered with an _________ _____ from the moment that teeth erupt
acquired pellicle
What is the significance of the pellicle?
- protective (barrier against acid)
- lubrication
- nidus for bacteria (development of plaque)
- aides in the attachment of calculus
The metabolic activity of the primary colonizers modifies the local microenvironment in ways that can…
influence the ability of other bacteria to survive in the dental plaque biofilm
Colonizing bacteria can be detected within ___ minutes after introduction of sterile enamel into the mouth
3
What are the three phases of colonization?
- 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
coadhesion
Biofilm maturation is a highly specific event that involves a __________ aggregation of different bacteria
nonrandom
The transition from early supragingival dental plaque to mature plaque growing below the gingival margin involves a shift in…
the microbial population from primarily gram-positive organisms to high numbers of gram-negative bacteria
What are the stages of biofilm formation?
Stage 1- pellicle formation
Stage 2 - bacterial colonization (day 1-14)
Stage 3 - plaque maturation (14-24)
At what stage/day is gingivitis evident?
stage 3 - plaque formation
day 14-24
What happens on day 1 of biofilm formation?
gram (+) cocci
What happens on days 2-4 of biofilm formation?
filamentous forms grow on cocci; intercellular matrix forms and connects colonies
What happens on days 4-7 of biofilm formation?
filamentous forms increase; rods and fusobacteria appear
What happens on days 7-14 of biofilm formation?
vibrios and spirochetes appear; gram (-) species increase; clinical inflammation visible
What happens on days 14-24 of biofilm formation?
- Plaque is composed of densely packed vibrios, spirochetes and filamentous bacteria
- Biofilm is well-established; channels established to distribute nutrients, remove wastes, allow free-flowing bacteria to form new colonies
What are the steps from pellicle to biofilm formation?
Approximately _______% cocci during first 4 hours
47-85
Most abundant colonization occurs on what parts of the tooth initially?
proximal surfaces, fissures and gingival sulcus
Initial colonizers are gram ___ aerobic and faculative organisms
positive
Secondary colonizers are…
P. intermedia, P. gingivalis, Capnocytophaga species, spirochetes, motile rods, gram (-) anaerobic organisms
When energy sources are introduced (sucrose) microorganisms produce…
- Acid
- Intracellular polysaccharides (reserve energy source)
- Extracellular polysaccharides (glucans [dextrans] and fructans [levans])
What is dextrans?
Viscous, sticky substances that anchor bacteria to pellicle and stabilize plaque mass
What is levans?
energy source
What are the factors that affect plaque accumulation?
- Mechanical removal (forces from mastication, toothbrushing, tongue movement, etc.)
- Availability of nutrients
- Undisturbed environment
- Interaction between bacteria and host immune response
Organisms in biofilm _________X more resistant to antibiotics
1000-1500
Biofilm matrix has properties that slowdown _________ penetration
antibiotic
Do some patients form plaque faster than others?
Yes! Heavy and light plaque formers exist! However, in both cases, it takes days before the plaque is clinically visible. Patients cannot justify poor oral hygiene by being heavy plaque formers.
_____ _____ is rapidly liquefied by bacterial enzymes and cleared from the mouth by salivary flow/muscles of mastication
Food debris
Dental plaque is or is not a derivative or food debris?
IS NOT
Plaque can or cannot be removed by spraying water?
cannot
As plaque matures, it becomes resistant to…
mechanical removal
Biofilm forms in 3 stages and matures within _______ days
14-24 days
As bacteria search for nutrients, they migrate where?
sub gingivally
Host defends itself via inflammatory response; ________ is initiated
gingivitis
What should you know about materia alba?
What should you know about dental plaque?
What should you know about calculus?
