tooth solubility

Question 1

what are teeth (and bone) composed of?

Answer 1

calcium phosphate crystals held together by a protein matrix

Question 2

is the proportion of mineral higher in teeth or bones?

Answer 2

teeth

Question 3

which part of the tooth has the highest mineral content?

Answer 3

enamel- 95% mineral content

(dentine has 70%)

Question 4

what is the mineral component of teeth?

Answer 4

hydroyapatite

Question 5

what does an increase in H+ do to calcium phosphate solubility?

Answer 5

increases it

Question 6

what does an increase in calcium phosphate concentration do to tooth solubility?

Answer 6

decreases it, promotes re-mineralisation

Question 7

what causes dissolution (erosion) of tooth enamel?

Answer 7

• Low pH drinks
• Some drinks contain chelating agents that bind calcium ions e.g. citric acid in orange juice, aiding erosion​

Question 8

what is the difference between tooth erosion and caries?

Answer 8

Erosion is the direct effect of acids from the diet on teeth, whereas caries involves acids produced by plaque bacteria​

Question 9

what is fluoride effective at?

Answer 9

reducing detal caries

Question 10

what is fluoroapatite?

Answer 10

OH- ions in hydroxyapatite are replaced with F- ions- these F- ions fit into the crystal better making it more stable and less soluble in acid

Question 11

what are the three ways in which fluoride acts in the oral cavity?

Answer 11

Reduces enamel solubility at low pH​
Inhibits bacterial metabolism of carbohydrates​
Promotes enamel remineralisation by saliva​