caries and tooth structure

Question 1

caries definition

Answer 1

localised destruction of susceptible dental hard tissues by acidic by products from bacterial fermentation of dietary carbohydrates

Question 2

what 4 things are needed for caries to occur

Answer 2

tooth, bacteria(plaque) , diet (sugars), time

Question 3

white spot lesions

Answer 3

demineralisation of enamel but not the loss of structure

appear on enamel as a chalky white colour

Question 4

describe the structure of white spot lesions

Answer 4

the enamel at the surface has low levels of demineralistaion as it is able to remineralise
the body of the lesion which is deeper in the enamel sees high levels of demineralisation
because of the surface remineralising the structure remains in tact.. up until a point at which is collapses

Question 5

demineralisation of enamel

Answer 5

mineral content from tissues surrounding the rods is removed causing enlarged gaps between rods
rods and their length remain preserved

Question 6

smooth surface and interproximal lesions shape

Answer 6

triangular with the base at enamel surface and point towards dentine and pulp

Question 7

pits and fissure caries shape

Answer 7

triangular shaped with point towards enamel surface and base at EDJ

Question 8

describe the process of caries

Answer 8

1 - demineralisation of enamel but structure remains intact
2 - initial demineralisation makes dentine tubules become sclerotic (unresponsive)
3 - dentine also begins to demineralise and tertiary dentine production begins
4 - lesioon progresses and enamel structure collapses
5 - enamel collapse continues and lesion pregresses into dentine causing it to also collapse

Question 9

what does lack of mineralisation allow

Answer 9

bacterial invasion

Question 10

if a white spot lesion is away from the gingival margin what does this suggest

Answer 10

it is remineralised and the lesion is now inactive

Question 11

describe the differences in plaque pH changes between sound tooth, inactive lesion and an active lesion and why is this the case

Answer 11

sound tooth - drop then quickly returns
inactive - pH drops to lower than sound but returns to normal fairly quick
active - sees large pH drop which is persistent
micro organisms in active lesions use sugars to produce acids much more effectively

Question 12

demineralisation shape in dentine

Answer 12

triangular with base at EDJ and point towards pulp

Question 13

D1 lesion

Answer 13

enamel lesions with intact surfaces

Question 14

D2 lesion

Answer 14

cavities in enamel

Question 15

D3 lesion

Answer 15

clinically detectable lesion in dentine

Question 16

D4 lesion

Answer 16

lesions into pulp

Question 17

sensitivity

Answer 17

% of disease found correctly

Question 18

specifity

Answer 18

% of health found correctly