Exam Unit 314 Flashcards
Radiation can be: Seen Heard Felt None of the above
None of the above
Quality assurance in radiography is a?
Legal requirement
Recall patients who have a high caries risk should have bitewings at what intervals?
6 months
What is the purpose of black paper in intraoral film packets?
Prevents exposure of the film to light
What is classed as a safe level of X-ray exposure?
There isn’t a safe level
What are extraoral cassettes marked with?
The letter L
What type of waste are X-ray processing chemicals?
Non-infectious hazardous
What is the reason for the exposure fault elongation of the image?
Collimator angulation too shallow
what is the reason for the exposure fault foreshortening of the image?
Collimator angulation too shallow
What is the reason for the exposure fault Ccning?
Collimator angulation is not central
What is the reason for the exposure fault blurred image?
Patient or collimator moved during exposure
what is the reason for the exposure fault fogged film?
exposed to light before exposure
intraoral films are what colour?
pale green
what is the reason for the exposure fault blank film?
X-ray machine not switched on
what causes a crazed pattern on the film?
film dried too quickly over a strong heat source
which legislation states that waste developer chemicals should be collected by licensed waste contractors?
Environmental protection act
whose responsibility is it to adhere to the principles of justification and optimisation?
IRMER practitioner Ionising Radiation (Medical Exposure) Regulations
What should a lateral oblique radiograph show?
Posterior portion of one side of the mandible
If a film which had been developed showed severe angulation faults what quality grade would it be given?
3
What quality score would be given to a radiograph that wasn’t as dark as usual due to chemicals becoming spent, but was still readable?
2
Details must be provided to show analysis of a radiograph has taken place as part of the quality assurance log. Which grades must this be completed for?
All grades
The quality assurance log should demonstrate that what percentage of radiographs have been graded a 1 as a minimum?
70%
According to IRR99 the controlled area should be what distance from the machine head?
1.5m
The pimple of an X-ray should be?
facing the x-ray tube
According to IRR99 the safety zone should be what distance from the machine head?
2m
Stochastic effects are what?
Effects that occur by chance and which may occur without a threshold level of dose.
If X-ray equipment appears to be damaged or leaking who should be notified?
The RPA (radiation protection advisor)
What do X-ray photons do to the silver halide crystals that cover a film?
Penetrate them to reach the film
What does a chronic periapical abscess show up as on an X-ray?
Circular area at the apex of a tooth
If a dentist wanted to assess existing restorations on LL6 and 7 what would be the best radiograph to take?
Bitewing
Which periapical technique allows for the actual tooth length to be captured?
Paralleling
Which type of radiograph is used extensively in orthodontics, in comparison to others?
Cephalostats
Bitewings should show:
The crowns of premolar and molar teeth
Developer converts the sensitised silver halide crystals on a film into black metallic silver which produces which parts of the image?
White parts
Why should X-ray solutions be kept covered?
To reduce oxidisation
What is used to take a digital X-ray?
Sensor plate
During digital radiographs X-ray energy is released as light and converted into what?
Photons
What is the main reason out of date film should not be used?
Film will not expose correctly
What do intraoral film packets have to help identify the correct orientation?
Marked with a pimple
The larger the number on an X-ray film packet:
The larger the film
How many steps are there in manual film processing?
Four
Bitewings are used for?
Detection of caries
Which step out of the following helps prevent a large radiolucent area near the palate as seen on panoramic X-rays?
By the patient smiling with their lips closed
By the patient smiling with their lips open
By the patient placing their tongue in the roof of their mouth
Having the patient bite on a fixed bite block
By the patient placing their tongue in the roof of their mouth
At what point can the red safety light be switched off?
Red light needs to stay on until the film is fixed, at this stage normal lights can then be placed on
In manual processing a film should be immersed in developer for:
5 minutes
In manual processing a film should be immersed in fixer for:
8-10 minutes
Processing chemicals should be disposed of as:
Non infectious chemical waste
Digital radiography eliminates the need for:
Chemicals
Orthopantomographs show:
Both jaws in full and all teeth
Cephalostats are used extensively in:
Orthodontics
A lateral oblique radiograph shows:
The jaw and molar teeth of either left or right hand side
Extraoral cassettes contain how many intensifying screens
2 intensifying screens
Occlusal radiographs show:
Either mandible or maxilla
The two techniques used to take periapical xray’s are
Bisecting angle and paralleling
Which is the best radiograph to take for assessment of the antral floor?
OPG
A patient attends with a suspected carious lesion in the lower right first molar tooth. Which radiographic view would normally be taken to diagnose this lesion? Dental pantomograph Horizontal bite-wing Occlusal Periapical Vertical bite-wing
Horizontal bite-wing
This view is routinely used to view the interproximal areas of the posterior teeth.
The stages of manual chemical processing are:
Develop, wash, fix, wash, dry
How often should regular maintenance of x-ray equipment be carried out?
Every 3 years
What makes up an intraoral film?
- Plastic envelope
- Black paper
- Film
- Lead foil
Vertical bitewings are useful to show?
Periodontal bone levels of posterior teeth
True pockets
Midroot of the uppers to midroot of the lowers
Periapical are useful to show:
Decting abscesses
Root morphology before XLA
Endo
Perio status
Occlusal are useful for:
Detecting supernumerary teeth
Evaluation of cysts/tumors
To view unerupted teeth
Intensifying screens do what?
They reduce the dose of radiation exposure. They also intensify the x-ray photons by producing a larger amount of light photons.
OPG is useful for:
Ortho assessment Assessment of wisdom teeth Assessment of bone loss Implant planning Diagnosing jaw fractures
Cephalostat are useful for:
Ortho treatment planning
Monitoring jaw growth
Monitoring treatment progress
A fogged films means:
The film was exposed to light before exposure.
An elongated image means:
The collimator angle was too shallow - it creates a long image.
A foreshortening image means:
The collimator angle was too steep - it creates a squat image
A coning fault is:
The collimator angle was not central to the film - part of the image will be missing
Blurred image means:
The patient or X-ray tube moved during exposure
A transparent image or faint imagine with an overlaying pattern means:
The film was placed the wrong way round. The lead foil pattern may be shown on the film
Blank spots on the radiograph means:
The film was splashed with fixer before developing
Brown or green stains on the radiograph means:
Inadequate fixing due to old solution being used
A crazed pattern on a radiograph means:
The film dried too quickly
Cystals on film means:
That the radiograph wasn’t washed sufficiently after fixing
Where should fixer and developer be stored?
On a low shelf in a cool and dry place
What is Ionising Radiation?
X-rays
Electromagnetic wave (short)
Travel in straight lines
They are invisible, cannot be felt or heard
List the 3 principles of ALARP/ALARA
F speed film
Shorter exposure time
Rectangular Collimator
List roles and responsibilities of the Legal Person
Responsible for all staff to comply with both regulations
Appoint an RPA
Appoint an RPS
Draw up and display set of Local Rules - with help from RPA
Organise 3 yearly checks of x-ray equipment
Which organisation has to be notified when using ionising radiation on the dental premises?
Health & Safety Executive
Which piece of equipment is used in Direct digital imaging?
Digital Sensor
Which piece of equipment is used in Indirect digital imaging?
Phosphor Plate
Which intra oral film is the largest?
Anterior Occlusal
Where would an extra oral film be positioned?
Outside the patient’s mouth
Is Developer an alkaline or acidic solution?
Alkaline
What is the temperature range of the processing chemicals?
18-22oC
What has happened if there was a crazed pattern on a radiograph?
The radiograph has dried too quickly
What would cause the loss of a film?
Stuck to the sides of the processing tanks
How will a radiograph appear if it has been exposed to light?
Fogged
Foggy
Black
Which regulation would the processing solutions be included under?
COSHH
Control of Substances Hazardous to Health
What rating is given to a radiograph that has some errors but is still diagnostically acceptable?
2
What rating would be given to a radiograph that is unacceptable and a retake would be required?
3
In quality assurance scoring what rating is given to a radiograph that has no errors at all and is excellent?
1
What is the purpose of a quality assurance programme?
To identify any occurring problems so that they can be addressed to avoid retakes and re -exposure for the patient
How would you store dental film?
In a cool, dark, dry place
Always use older date first (rotate stock)
Away from sources of radiation and processing solutions
Not on a window sill - away from direct sunlight
On its narrow side
What information would be included when labelling a radiograph?
Patient Name Date of Birth Patient ID number Date Dentist initials Type of radiograph Tooth notation
If the temperature of the developer is 22oC how long should the developing time be?
4 minutes
If the developer temperature is 20oC, how long should the developing time be?
5 minutes
How long should the film be in the fixer solution for?
2 minutes
How long is the final rinse/wash?
5-10 minutes in running water
