Radiography of caries and perio disease

Question 1

what must there be to detect caries on a radiograph?

Answer 1

30-40% of demineralisation - caries will be visible
must be distinguishable from enamel/dentine
film must be well exposed and well porcessed
must have optimum viewing conditions

Question 2

limitations with caries diagnosis and radiographs?

Answer 2

from radiograph cannot tell if lesion active/inactive

superimposition - image only 2D

Question 3

what can be mistaken for caries?

Answer 3

cervical burnout
mach effect - contrast below dense restorations
air/lip shadow at premolar region
dentine surrounding radio-opaque zone under amalgam
radiolucent restorations

Question 4

limitations to caries diagnosis?

Answer 4

technique
anatomy
exposure factors
2D image

Question 5

how is periodontal disease assesed?

Answer 5

a combination of clinical and radiographic exam

Question 6

what do radiographs tell us about bone?

Answer 6

show the amount of bone remaining in relations to length of tooth