Tooth Solubility Flashcards
what do teeth and bone consist of
calcium phosphate crystals held together by a mainly protein matrix
is the proportion of mineral high in teeth or in bones
teeth
in which component of the teeth is there a higher mineral content
enamel, at 95%
what is the mineral component of teeth known as
hydroxyapatite
what gives teeth and bone their rigidity
hydroxyapatite
what increases the solubilisation of calcium phosphate
an increase in the hydrogen ion concentration
how does an increase in the concentration of calcium or phosphate promote remineralisation
the increase in concentration causes the equilibrium to shift to the left, inhibiting solubilisation and promoting the remineralisation
what can low pH drinks to teeth
it causes dissolution of the tooth enamel
what is dissolution
the erosion
what is an example of a chelating agent in drinks
citric acid in orange juice
what is erosion the direct effect of
acids from the diet on teeth
how does fluoride act (3)
- reduces enamel solubility at low pH
- inhibits bacterail metabolism of carbohydrates
- promotes enamel remineralisation by saliva
why is fluoride effective at reducing dental caries
it is incorporated into hydroxyapatite to form fluoroapatite, the hydroxide ions are replaced by the fluoride ions. since these ions are smaller than the hydroxide ions, they fit better into the crystal, rendering it more stable and therefore less soluble in acid
why is calcium phosphate used in experiments that demonstrate tooth solubility
it is very similar to hydroxyapatite, and pure preparations of human enamel are hard to acquire
what will happen to allens reagent if there is PO4 present
a blue colour will develop