Caries & Periapical Pathology

Question 1

Justification for radiation exposure?

Answer 1

• selection of appropriate radiograph should be based on patient’s history & clinical examination
• Routine/screening radiograph prescriptions must be based on knowledge of the prevalence of disease

Question 2

Interpretation of justificatoin for radiation exposure depends on:

Answer 2

• Knowledge of how image is acquired
• Knowledge of anatomy
• Knowledge of disease process

Question 3

Interpretation of exposure also depends on understanding the effects of:

Answer 3

• Positioning
• Exposure
• Processing
• For digital imaging, the programme algorithms & computer factors

Question 4

Which radiograph should we take in a particular situation?

Answer 4

ALARP - As Low As Reasonably Practicable

Question 5

What is dose in relation to the patient?

Answer 5

The amount of radiation absorbed by the patient

Question 6

How are carious lesions detected?

Answer 6

Detected radiographically when there has been sufficient demineralisation

Question 7

What type of radiograph is considered to be “gold standard”?

Answer 7

Bitewings

Question 8

Recommended techniques of radiograph considered for diagnosing caries?

Answer 8

1- Bitewings - usually horizontal

2- paralleling periapicals

Question 9

Types of bitewings radiographs?

Answer 9

Horizontal and vertical

Question 10

What are you expecting to see in a radiograph?

Answer 10

• Crowns of the teeth and coronal portion of roots
• Contact points with none or little overlap
• Distinguish layers of teeth
• Overhangs or etc if restoration present

Question 11

What can be mistaken for caries?

Answer 11

• Cervical burnout

- Lip shadow in premolar region

Question 12

Limitation of caries diagnosis?

Answer 12

• Overlap
• Technique
• Anatomy

Question 13

Technique of paralleling periapicals and bitewings:

Answer 13

• Film is parallel to long axis of tooth

- xray beam at 90º to film and tooth

Question 14

Paralleling technique:

Answer 14

• Film and tooth parallel vertically - if not, distortion may occur

Question 15

High risk child radiograph taken..

Answer 15

6 months

Question 16

Moderate risk child radiograph taken..

Answer 16

Annually

Question 17

Low risk child radiograph taken…

Answer 17

12-18 months deciduous

>= 24 months permanent teeth

Question 18

Mandible trabeula pattern..

Answer 18

Thick, close together, horizontally aligned

Question 19

Maxilla trabeula pattern..

Answer 19

Finer, more widely spaced, no obvious alignment pattern

Question 20

Radiology and peri-radicular disease. The 3 most important features:

Answer 20

• Radiolucent line representing the periodontal ligament space
• radiopaque line representing lamina dura
• Trabecula pattern and density of surrounding bone

These can be lost due to personal variation

Question 21

Limitation of radiographs due to:

Answer 21

• Contrast
• Resolution
• Superimposition etc.

Question 22

Radiographic appearance of periapical pathology:

Answer 22

Initial acute inflammation

- no apparent changes or possible widening of periodontal ligament space

Question 23

Where does the initial spread of inflammation cause:

Answer 23

Loss of lamina dura at apex

Question 24

Further inflammatory spread..

Answer 24

Periapical bone loss

Question 25

Initial chronic inflammation leads to..

Answer 25

no bone destruction can be seen or dense sclerotic bone periapically

Question 26

Long standing chronic inflammation:

Answer 26

Circumscribed, well defined, radiolucent area periapically with sclerotic bone surrounding

Question 27

What is radiolucency sometimes described as:

Answer 27

Rarefying osteitis