Intro to Dental Radiology

Question 1

What are the 3 principles of radiation protection?

Answer 1

1. Justification
   - Why the benefits outweigh the risk
2. Optimisation
   - ALARA
   - As low as reasonably achievable
3. Dose limitation
   - For radiation workers NOT patients

Question 2

What is the function of an image receptor?

Answer 2

Changes an x-ray beam into a visible image

Question 3

What are the most popular type of image receptor - and their subtypes? (2)

Answer 3

1. DIGITAL RECEPTORS
   Direct - Panoramics

Indirect - Intra-orals

2. X-RAY FILM PACKETS
   Intraoral

Question 4

Define the term processing

Answer 4

Conversion of latent image to permanent visible image

• Digital
• Chemical

Question 5

Define a radiographic image

Answer 5

A record of the pattern of attenuation of the X-ray beam after if has passed through matter

Question 6

Define attenuation

Answer 6

The gradual intensity reduction of an X-ray beam

Question 7

What is attenuation caused by?

Answer 7

Absorption or scatter of photons from the beam

Question 8

Where is an X-ray film placed intra-oral radiograph?

Answer 8

X-ray film is inside the mouth

Question 9

Where is an X-ray film placed in an extra-oral radiograph?

Answer 9

X-ray film is outside the mouth

Question 10

List examples of intra-oral radiographs (3)

Answer 10

1. Bitewings - premolars to molars
2. Periapicals
3. Occlusals

Question 11

List examples of extra-oral radiographs (4)

Answer 11

1. Panoramic
2. Cephalometric
3. CBCT
4. Dental Computed Tomography CT

Question 12

What does a panoramic radiograph show?

Answer 12

Shows entire mouth in 1 X-ray

Useful in orthodontics + for impacted wisdom teeth

Question 13

What does a cephalometric radiograph show?

Answer 13

• Shows entire side of the head
• Shows Facial bones to measure dental + skeletal relationships
• Includes soft tissue profile

Question 14

Name 2 advantages of a CBCT > CT

Answer 14

1. Rotates around the patients head in one single rotation and captures all the data, unlike the CT scan which collects flat slices over several rotations –> exposing patient to a higher level of radiation
2. Can be used in a dentist whereas CT requires a hospital setting

Question 15

What type of pathology can be identified from a Bitewing radiograph? (3)

Answer 15

1. Caries
   - Interproximal
   - Cervical
   - Occlusal
   - Buccal
   - Lingual
2. Restorations
   - Ledges
   - Defects
3. Interdental bone changes

Question 16

What type of pathology can be identified from a Periapical radiograph?

Answer 16

1. Caries (usually BWs)
2. Trauma
3. Pulpal pathology
4. Non carious tooth surface loss
5. Root pathology
6. Supporting bone

Question 17

Whats a key difference between an occlusal radiograph and periapicals/BWs?

Answer 17

Larger image receptor