Dental Plaque And Caries Flashcards
What is dental biofilm
The complex microbial community that develops on a tooth surface embedded in a matrix of polymers of bacterial and saliva
What are the 4 needs for caries progression
Host (tooth)
Time
Diet
Plaque (bacteria)
How many days do clinical symptoms of gingivitis develop
Within 21 days after plaque was allowed to accumulate
What is the intercellular matrix consisted of in dental plaque
Organic and inorganic material derived from saliva, gingival cervicular fluid and bacterial products
What are the 4 organic components of dental plaque
Glycoproteins from saliva
Polysaccharides produced by bacteria
Proteins
Lipid material from disrupted bacteria, host cells and food debris
What are 5 inorganic components of dental plaque
Calcium
Phosphorus
Sodium
Potassium
Fluoride
How does calculus form
As the mineral content increases the plaque mass becomes calcified to form calculus
What are the 3 main phases of dental plaque formation
Formation of pellicle on the tooth surface
Initial adhesion/attachment of bacteria
Colonisation/plaque maturation
What is the main microorganism found in dental plaque
Streptococcus mutans
What are 4 other species of streptococcus
S sanguis
S oralis
S mitis
S mutans
How long does it take for single bacterial cells to form on the tooth surface
4 hours
How long does it take for microcolonies to form on the tooth surface
4-24 hours
How long does it take for bacteria to mature on the tooth surface
14 days
What type of gram is streptococcus
Gram negative bacteria
What are the 3 main benefits of saliva
Washes away carbohydrates
Promotes remineralisation
Acts as a buffer
How does saliva promote remineralisation
Through calcium, phosphate, hydroxyl and fluoride ions
How does saliva act as a buffer
Through sodium and bicarbonate ions
What pH level does enamel demineralise
5.5
What pH level does dentine demineralise
6.5
What 2 bacterial loads reduce plaque
Lysozyme and lgA
What attaches late colonisers to the tooth biofilm
Fusobacterium nucleatum
Which stage of colonisers are gram positive
Early colonisers
Which stage of colonisers are gram negative
Late colonisers
Why are gram negative bacteria more resistant against antibodies
Because of their impenetrable cell wall
