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BDS 2: Adult Restorative > Dental Plaque > Flashcards

Flashcards in Dental Plaque Deck (22)
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What are some general properties of biofilm? (4)

- Protection (ie moisture, predators)
- Slow growth rate
- Get their physical characteristics from surface
- The variation of biofilm leads to their metabolic interactions


Define dental plaque

A complex microbial community on a tooth surface, embedded in a matrix of polymers of bacterial and salivary origin (BIOFILM)


Define biofilm

Biofilms are a collective of one or more types of microorganisms that can grow on many different surfaces


How are the properties of micro-organisms growing in microfilm different to ones growing from planktonic growth? (2)

- Microfilm grows slower
- Microfilm much more resistant to antimicrobial agents


Give some examples of synergistic interactions between organisms in a biofilm (5)

- Enzyme sharing
- Food chains
- Co-adhesion
- Cell-to-cell signalling
- Gene transfer


Give some examples of antagonistic interactions between organisms in a biofilm (6)

- Bacteriocin production
- H2O2 production
- Organic acid production
- Bacteriophage release
- Competition for nutrients
- Predation


Name some different types of dental plaque (5)

(Think location)

- Fissure plaque
- Approximal plaque
- Gingival crevice plaque
- Denture plaque
- Calculus


What are the 5 steps of the development of dental plaque

1. Acquired enamel pellicle is deposited on clean tooth surface about 1μm thick

2. Pioneer species of bacteria will adhere to the acquired pellicle

3. Pioneering species multiply and form a confluent layer

4. Accumulated bacterial growth leads to a decrease in oxygen tension which cultures additional anaerobic bacteria

5. Plaque maturity


After brushing your teeth how long does it take for the acquired enamel pellicle to form?

2 Hours


What is the acquired enamel pellicle composed of? (5)

{3 Molecules + 2 fluids}

- Proteins
- Lipids
- Glycoproteins
- Saliva
- Gingival crevicular fluid


What components of the enamel pellicle are bacteria derived? (4)

- Glycosyl transferase
- Glucans
- Fructans
- Bacterial cell fragments


What components of the enamel pellicle are host derived? (5)

- Acidic, proline-rich proteins
- Amylase
- Lysozyme
- Albumin
- Immunoglobulins


What are the interactions that attract pioneer bacteria to the pellicle?

Van der Waals


What are the interactions that repel pioneer bacteria to the pellicle?

Electrostatic repulsion between negatively charged bacterial cell and pellicle surface.


Explain the molecular interactions between bacteria and pellicle

Bacteriums have adhesive molecules that are complementary to the pellicle surface receptors


During the multiplication stage of the pioneer species, co-aggregation occurs, what is this?

Cell-to-cell interactions leading to distinctly different bacterial species becoming predetermined ‘partners’ in forming plaque.


Mature plaque is a _____ community

Mature plaque is a climax community


Are there any benefits of dental plaque for the host?

Small amount of dental plaque can help exclude exogenous organisms


How can dental plaque help in the exclusion of exogenous organism from entering the mouth? (3)

- Competition for adhesion receptor sites
- Competition for nutrients and co-factors
- Production of inhibitory substances, eg acids, H2O2


What is calculus?

Calcified dental plaque


What is calculus composed of? (3)

- Mineral deposits
- Proteins
- Carbohydrates


Where is the most predominant supra gingival location for calculus?

Near salivary ducts