Week 3 Flashcards
Steps in colonization of the oral cavity starting with birth?
Day 1- facultative and aerobic bacteria from birth
Day 2- anaerobic bacteria found
Day 14- mature microbiota established in gut
2 years- whole microbiota formed 10^14 total
Tooth eruption = more complex flora
Is the oral microbiota harmful?
No most are commensal and or beneficial
How much bacteria do we have in and on our bodies?
~ 2 kg
How many different types of bacteria are found in the mouth?
Over 600
When infection with a microbe happens what are the choices and how much damage happens over time?
Commensalism- no damage over time unless it gets out of control and leads to disease- in which case it damage amount goes up over time.
Colonization- damage goes up over time and can lead to clearing the infection, disease, or persistence.
Both colonization and disease can lead to persistence where damage level is constant and high over time
Disease has two outcomes: death or eradication by immune or tx
Name the 6 major ecosystems in the mouth?
- Keratinized intraoral supragingival tissue and hard surfaces
- Perio pocket (including around implants)
- Non-K tissues- buccal, palate and floor of mouth
- Dorsum of tongue
- Tonsils
- Saliva
3.
Describe plaque and the locations it is found?
Structured, layered, yellow grey,
Found on hard surfaces of teeth and restorations both above and below gums
What is materia alba?
White cheesecake like substance that is soft and easily sprayed off with water made from salivary proteins, bacteria, dead epithelial cells and some occasional food debris.
No organizational structure
What is plaque made of?
Bacteria in a matrix of salivary glycoproteins and extra cellular polysaccharides
It is a biofilm
Can plaque be removed by sprays or rinsing?
Nope impossible needs physical scraping
What is dental pellicle?
A substance that coats every surface of the mouth derived from saliva made of glycoproteins, proline rich proteins, phosphoproteins, histidine rich proteins and enzymes
Aka proteins that are a mix of glyco, phospho, histidine and proline combined with enzymes
How does dental pellicle adhere to teeth?
Electrostatic, Vanderwalls and hydrophobic forces
How fast does pellicle form after cleaning teeth?
Within nanoseconds
3 major phases of plaque formation?
- Pellicle forms
- Initial adhesion and attachment of bacteria
- Colonization and plaque maturation
Three phases of bacterial attachment?
- Random contact of bacteria with hard surface aka transport of bacteria to the tooth surface
- Initial reversible adhesion
- Attachment with a firm anchorage by reactions between bacterial adhesins and pellicle receptors
After Step 3 it needs to be scraped off aka physically removed
Which phases of bacterial attachment are non specific?
Phase 1 and 2 are random and phase 3 depends on specific interactions between bacterial surface proteins (adhesins) and pellicle receptors
Why are teeth so good at accumulating plaque?
Hard non-shedding surface to attach to
A part of our ectoderm that doesn’t shed providing a home and “port of entry” for perio pathogens
When full mouth extractions are done does the type of bacteria in the mouth stay the same?
No key perio pathogens disappear
Describe the specific location of plaque growth on teeth?
Starts at gingival margin and interdental spaces and grows toward the corona
What is Supragingival plaque?
Plaque located outside of the perio pocket that starts at the gingival margin (touch’s the margin)
What type of bacteria makes up the first layer (touching the tooth) of supragingival plaque?
Gram positive cocci and short rods
What type of bacteria makes up the outer layer (surface) of supragingival plaque?
Gram negative rods and filaments, spirochetes
What is a major factor is causing plaque to stick to the surface of teeth?
The roughness of the surface.
Fine polishing paste or glycine powder for air polishing
What does thicker plaque contain and is it more or less pathogenic?
More pathogenic
Contains more motile bacteria like spirochetes and is packed denser so more organisms