Quiz 4 Flashcards
What does the modern plaque hypothesis say about periodontopathic flora?
That it is necessary, but not sufficient for the disease. The periodontopathic flora is the etiology, but not the pathogenesis.
What are the five aspects of microbial plaque that are considered the etiology of periodontal disease?
Bacteria Fungus Protozoa Virus Mycoplasm
Do high socioeconomic status people have higher or lower periodontal disease?
They have higher, they drink water through water bottles instead of fluoridated tap water.
How is dental calculus and dental plaque involved with periodontal disease?
Dental plaque is the etiologic factor, while dental calculus is like the coral reef and provides an environment for the bacteria to grow or for the biofilm to grow on it. There is both supragingival and subgingival calculus.
What are some of the basic biofilm properties?
Microorganisms are arranged in microcolonies with channels between the microcolonies
Microcolonies are surrounded by protective matrix (which affects antibiotics effectiveness)
Microbial gene expression differs when microorganisms are in a biofilm (Quorum sensing)
Microorganisms in biofilm are resistant to antibiotics,
antimicrobials, and host response
What is microbial co-aggregation?
This is when the bacteria releases enzymes that cleave off terminal carbohydrate ends and allow them to attach to bacterial receptors as early colonizers on the plaque, and then they can add on and attach to each other, as late colonizers. And remember, the deeper the organisms are and the closer they are to the tooth, the more anaerobic they will be.
Who modified Koch’s postulates for periodontics and came up with the chart?
Socranksy
Which two colors from the chart are associated with organisms involved in disease sites?
Orange and Red
What are the three organisms in the red group?
- Porphyromonas Gingivalis (- and nonmotile)
- Bacteroides Forsythus (- and nonmotile)
- Treponema Denticola (motile)
What are the four hypothesized biofilm resistance mechanisms?
- The antibiotic penetrates slowly or incompletely
- A concentration gradient of a metabolic substrate or product leads to zones of slow or non-growing bacteria.
- An adaptive stress response is expressed by some of the cells
- A small fraction of the cells differentiate into a highly protected persister state
What does the fluid gradient do in plaque biofilm?
It helps move nutrients around, including into and out of the environment, and helps allow for bacterial communication.
Why is the green group so important?
They are mostly Gram negative and they are highly involved with the disease progression.
For periodontal disease, what are the main things involved with the etiology, initiation, and progression?
Etiology: Microbial plaque
Initiation: Non-specific plaque accumulation
Progression: Gram negative bacteria and susceptible host
In terms of plaque distribution, where around the tooth is most of the subgingival plaque found?
Distal, then mid-buccal, then lingual. Posterior teeth are worse off than anterior. Any tooth brush , regardless of the brushing method, does not completely remove interdental plaque. Even for patients with wide-open dental embrasures.
There is a strong relationship between oral hygiene and gingivitis. True or False?
True
There is a strong relationship between oral hygiene and the risk for developing periodontitis. True or False?
False
All gingivitis progresses to periodontitis and all periodontitis is preceded by gingivitis. True or False for both?
False, True
What is the definition of a virulence factor?
It is a property that enables the bacterium to cause disease. It can be something that allows for attachment, creates inflammatory responses, protection, etc.
Fimbrea is a virulence factor, what is its MOA?
Bacterial attachment, prevention of phagocytosis
Capsule is a virulence factor, what is its MOA?
Protection, attachment, prevention of phagocytosis
Endotoxin is a virulence factor, what is its MOA?
Activation of inflammatory response, cytokine production, bone resorption
What does bacteria avoid by attaching to surfaces like enamel, cementum, plaque, connective tissue?
It avoids displacement by the gingival crevicular fluid flow. This ability to adhere is a virulence factor.