week 10 Flashcards
what is caries
sugar demineralises the enamel as it feeds some of the bacteria in the mouth. This gives them energy to produce acid which attacks the surface of the teeth, dissolving enamel minerals. Flouride toothpaste help saliva remineralise the enamel. If this becomes unbalanced due to brushing techniques or or other causes, caries occur.
What are the first visible signs of the carious process
Areas of discolouration, roughness, tenderness or inflammation
what are the three critical factors for caries to occur
The biofilm or plaque that grows on teeth or other hard surfaces
The diet
The health or state of the oral environment
What factors could increase the likelihood of a carious lesion occuring
Acid producing bacteria
Sub-normal Salivary flow
Frequent eating/drinking of fermentable carbohydrates
What factors could be considered protective in the oral environment and assist in the prevention of a carious lesion
Good quality and quantity of saliva flow (hydration and sugar free gum)
fluoride use
antibacterials that reduce the threat of pathogenic bacteria (chlorohexine, iodine, xytitol)
reduce frequency of diet
remove cariogenic bacteria (OH practise)
what are the three hypothesis for the role plaque plays in the caries proccess
Specific plaque hypothesis
Non specific
Ecological
Which plaque hypothesis is currently accepted
Ecological plaque hypothesis
What is the specific plaque hypothesis
specific types of bacteria or microorganisms are responsible for the progression
What is the non specific plaque hypothesis
you do not need a specific amount of plaque for disease progression, but overall bacteria and a specific threshold
What is the ecological plaque hypothesis
If we keep everything under control (bacteria balanced) there will be no disease progression
what bacteria are likely to cause caries
streptococcus mutans
lactobacillus
why is this bacteria likely to cause caries
- they synthesis a type of water (insoluble glucan) - binds well, increases thickness of plaqueand produce an environment that they like
- they produce large amounts of acid particularly lactic acid (demineralisation)
- synthesis intracellular polysacharides which support continue acid production without dietary substrates (continue to produce throughout the night)
- are aciduric - thrive in low ph environments
what are the three historical studies which demonstrate the role of diet in the caries process
Vipeholm Study 1954
tristan de cunha
hopewood house
what is the vipeholm study 1954
more frequently patients were exposed to sugars, the higher the levels of caries
food retention influences risk (sticky)
what is the tristan de cunha study
sugar consumption correlated with caries
what is the hopewood house study
a diet with no carbohydrates or sugar reduces caries
what are intrinsic sugars
found inside cell structure - unproccessed foods, whole fruits and veg
NOT CARIOGENIC
what are extrinsic sugars
outside of cells of the food and drink
what are milk extrinsic sugars
lactose (dairy products)
NON CARIOGENIC
what are non milk extrinsic sugars
Table sugar, confectionary, soft drinks, biscuits, honey, juice
FERMENTABLE SUGARS
CARIOGENIC
what is the stephan curve
constant ph while not drinking or eating
when u eat or drink - produces acid and ph decreases
the lower the ph the more likely of demineralisation and tooth decay
recovery takes 30-60 minutes for ph to increase
snacking causes frequent acid challenges - not enough time to buffer system back baove 5.5ph - causes prolonged acid damage
how long does it take for pellicle formation
minutes after cleaning
how long does it take for bacterial attachment
0-24 hours
how long does it take for bacterial growth
4-24 hours
how long does it take for microbial succession
1-7 days
how long does it take for a mature biofilm
1 week or older
what is the index of caries experience for permanent teeth
DMFT - simole process that tells us how many teeth have been affected by dental caries
What does DMFT stand for
Decayed, missing, or filled teeth
What is the index of caries DMFS
Decayed missing of filled surfaces - instead of counting one tooth as a single measure - each surface of the tooth is counted
whats the difference between carious process, lesion and proggression
caries process is the interaction between the biofilm and the tooth surface
caries lesion is the manifestation of the stage of the process at one point in time
caries progression occurs when demineralisation and remineralisation are out of balance leading to net mineral loss
