Radiographs

Question 1

Name 2 regulations in relation to radiographs

Answer 1

1. IRR - Ionising Radiation Regulations

2. IRMER - Ionising Radiation Medical Exposure Regulations

Question 2

What is the major difference between IRR and IRMER?

Answer 2

IRR is in relation to staff and IRMER is in relation to patients

Question 3

Describe 4 parts of a selection criteria before taking radiographs

Answer 3

• Be clear what you want radiograph to show
• Unnecessary exposure must be avoided
• Not acceptable to take radiographs because patient hasn’t had any in a while
• Consider types of radiographs available to reduce radiation dose

Question 4

Name 3 components of taking a radiographs

Answer 4

1. Justification
2. Optimisation
3. Evaluation

Question 5

Describe justification of a radiograph

Answer 5

• Each must be justified as showing sufficient benefit
• Good practice but no legal requirement
• When referring, the referrer must supply details of radiograph history

Question 6

Give an example of a justification for bitewings

Answer 6

Interproximal caries

Question 7

Give an example of a justification for IOPAs

Answer 7

Apical pathology of the tooth

Question 8

What is the key mnemonic for optimisation of a radiograph?

Answer 8

ALARP - As Low As Reasonably Practicable

Question 9

Name 3 ways to ensure radiation is kept as low as reasonable practicable

Answer 9

• Ensure equipment is calibrated correctly, serviced etc
• Maintain skills
• Maintain knowledge

Question 10

Describe clinical evaluation of radiographs

Answer 10

• All radiographs must be reported on

- This includes any radiographs which quality is too poor to be diagnostically valuable

Question 11

What is quality assurance of a radiograph?

Answer 11

It is essential each radiograph is graded and information is used so deficiencies in systems can be recognised

Question 12

Describe the grading process of radiographs

Answer 12

1. Excellent - Over 70% of radiographs taken
2. Diagnostically acceptable - No more than 20%
3. Unacceptable - No more than 10%

Question 13

Name 3 most often used radiographs in restorative dentistry

Answer 13

1. Bitewing
2. Periapical (IOPAs)
3. Panoramic Tomography (OPT)

Question 14

What is the main indication for bitewing radiographs?

Answer 14

1. Detection of dental caries
2. Initial periodontal assessment
3. Radiographic assessment of restorations

Question 15

Describe carious lesions visible on radiographs

Answer 15

Detectable when there is enough demineralization to allow lesion to be differentiated from enamel and dentine

Question 16

Describe the frequency of bitewings taken for different types of patients

Answer 16

High risk - 6 months
Moderate risk - 12 months
Low risk - 24 months
Low risk children - 12 - 18 months

Question 17

Name 2 ways in which radiographs can be used to assess restorations

Answer 17

1. Assessment of ledges and overhangs

2. Marginal fit of cast restorations

Question 18

Describe a good technique to aid optimisation

Answer 18

A simple film holder will help position the film packet and facilitate positioning of the x-ray tubehead

Question 19

Describe 2 potential problems if holders are not used taking radiographs

Answer 19

1. Overlapping

2. Coning off

Question 20

Describe 2 things to note when radiographically assessing radiolucent areas

Answer 20

1. Caries v Burnout

2. Size of pulp chamber

Question 21

Describe 3 things to note when radiographically assessing radio-opaqueareas

Answer 21

1. Restorations, calculus and artefacts
2. Presence of root filling material
3. Presence of posts and pins

Question 22

Name 2 misleading shadows on a radiograph

Answer 22

1. Cervical burn-out

2. Radiopaque zone beneath amalgam restorations

Question 23

What is cervical burnout?

Answer 23

Artefactual phenomenon created by anatomy of teeth and variable penetration of x-ray beam

Question 24

Describe 3 characteristics of burnout

Answer 24

1. Located at neck of teeth
2. Triangular in shape
3. All teeth in radiograph usually affected

Question 25

Describe radiopaque zones beneath amalgam restorations

Answer 25

- Under restorations ions are released into demineralized dentine - Radiopacity of zone may make normal dentine appear darker

Question 26

What are the 6 main indications for taking IOPAs?

Answer 26

1. Detection of periapical infection 2. Assessment prior to crown of bridgework 3. Localised periodontal assessment 4. Bone loss 5. Before commencing, during and assessing endodontics 6. Assessment of operative appraisal of apical surgery

Question 27

Describe x-ray tube positioning

Answer 27

Should be positioned so that the beam meets the tooth and film at right angles in both vertical and horizontal planes

Question 28

Describe 2 potential problems with IOPAs if holders are positioned incorrectly

Answer 28

1. Foreshortening | 2. Elongation

Question 29

Describe 3 advantages of OPTs

Answer 29

1. Shows all teeth and supporting structures on one film 2. Technique is reasonably simple 3. Radiation dose is relatively low

Question 30

Describe 3 main restorative indications of OPTs

Answer 30

1. Overview of dental caries 2. Overview of periodontal disease 3. Implant placement assessment

Question 31

Name 4 non-restorative indications of OPTs

Answer 31

1. Orthodontic assessment 2. Establish size of jaw lesions 3. Fractures of the mandible 4. Assessment of third molars