Biochemical events in Dental Plaque Flashcards
Ultimately what causes caries?
Bacteria
How would you describe the structure of dental plaque?
Highly organised structure
What is the water and solid composition of dental plaque?
- 80% water
- 20% solid
20% of plaque composition is solid. What is this ‘solid’ made up from?
Give the compositions of these.
- 50% Bacterial and salivary proteins
- 25% Carbohydrates and lipids
- 25% Inorganic components
What are the carbohydrates and lipids in the dental plaque synthesised from?
Synthesised by the bacteria in the plaque
What is plaque fluid?
Extracellular aqueous phase of dental plaque
In nL how much plaque fluid can be found in a 500 μg wet weight plaque sample?
150 nL
What can changes in ionic composition of plaque fluid lead to?
Cariogenic conditions
What is rested plaque fluid?
Plaque fluid one to several hours after eating
What is starved plaque fluid?
Plaque fluid following overnight fasting
Which plaque fluid contains more amino acids? Rested or Starved?
Rested plaque fluid
Which plaque fluid is more acidic? Rested or Starved?
Rested plaque fluid
What is the main acid involved in caries formation?
Lactic acid
What contributes to the extent of pH drop after glucose challenge? (5)
- Type and amount of sugars available
- Bacteria present
- Salivary composition and flow
- Other food ingested
- Thickness and age of dental plaque
What is the resting plaque pH of a caries-inactive patient?
Compare this to a patient that is caries-prone
Resting pH roughly 6.5 - 7
Caries-prone has a lower resting pH
What affects the metabolic properties of plaque?
Bacterial composition affects metabolic properties of plaque
Which type of sugars cause the most dental caries?
Small sugars such as monosaccharides
What are the 3 ‘fates’ of pyruvate?
- Ethanol
- Lactic acid
- Further oxidation to return to citric acid cycle
What determines the fate of pyruvate?
The different types of bacteria
List some cariogenic bacteria (3)
- Streptococci
- Actinomyces
- Lactobacilli spp
Define Acidogenicity
The ability to produce acid rapidly from fermentable carbohydrate
Define Aciduricity
The ability to survive and continue to produce acid at acidic pH
