Unit 306 Flashcards
Why do we take dental radiographs?
To diagnose and detect
Dental caries on a radiograph shows up as…
a dark area extending inwards from the enamel.
Periodontal disease shows up as…
A loss of the lamina dura (compact bone)
loss of height of the alveolar bone
widening of the periodontal ligament space.
Periodontal and periapical abscesses show up as…
A dark circular area at the apex.
Destruction of the apical lamina dura and spongy bone.
Cysts show up as…
enlarged darker areas surrounding other structures
Can sometimes push tooth roots out of their normal positions.
Examples of Latrogenic problems caused by the dentist:
Overhanging restorations
Root perforations by posts.
If a 14 year old patient had still not recieved their UL3 what would a radiograph detect?
Supernumerary and unerupted teeth
To determine the congenital absence of unerupted teeth
What does congenital absence mean?
Permanent absence of tooth
If a patient had a large swelling on the jaw what could a radiograph determine?
Hard tissue lesions such as bone cysts, tumours
Examples of what treatments radiographs are used in:
Endodontics
Extraction
Orthodontics
Implants
Preparations crown/bridge
A type of ionising radiation…
X-ray
What type of radiation is an X-ray?
Electromagnetic
What does radiopaque mean and examples?
Radiation cant pass through
Appear light grey to white
Crowns, restorations
What does radiolucent mean and examples?
Radiation can pass through
Appear dark grey to black
Cavities, soft tissues
The outer layer of bone on an xray will appear whiter than the cancellous inner layer.
What is the reason behind x-rays hitting the atoms of the tissue cells?
Scatter or absorbtion
What can happen if radiation energy is absorbed into our tissue cells?
Tissue damage
If the radiation energy hit the chromosomes in our body what could happen?
Damage
Undergo change “MUTATION”
Possibly the chromosomes would die.
What does ALARP stand for?
As low as reasonably practicable
What does ALARA stand for?
As low as reasonably achievable
Where is the controlled zone when an x-ray is being took?
Inside the surgery with the patient.
Why should Quality assurance systems be regularly operated (audits)?
Ensure the dental images produced are to a consistently high standard.
Is ionising radiation potentially hazardous to health?
YES
Is there a safe level of use regarding radiation?
NO
What can an overdose of radiation cause?
Ranges from a mild burn to leukaemia and potentially death.
Who was the IRR17 enforced by?
HSE - Health and safety executive
IR(ME)R 2017 + IR(ME)R (NI) 2017 is enforced by in different areas of the UK:
CQC - england
HIW - Wales
IRMER Inspector - scotland
RQIA - northern ireland
Who is the IRR17 concerned with?
Staff
Who is the IRMER17 concerned with?
Staff and patients
What does scatter radiation do?
It bounces of tissue cells during exposure in an uncontrolled manner and can re-expose the patient several times.
Increasing the radiation dose.
What has been put in place to reduce the amount of scatter radiation from taking place?
- Use of fast films such as F speed intraoral films
- Short exposure time - modern x-ray machines, fast films and fast intensifying screens in extraoral cassettes.
- Rectangular collimator tubes - provide a parallel x-ray beam.
HSE - graded approach
Low risk - notify the HSE
Medium risk - Register with the HSE
High risk - Recieve consent from the HSE
What grade does dental radiography fall into with the HSE?
Medium risk
Who is the legal person?
Employer - internal
Ensures the workplaces full compliance with both sets of regulations.
Who is the radiation protection Advisor RPA ?
Specialist person/organisation - external
Give advice on staff and public safety in relation to both sets of regulations.
Routine radiation surverys
Who is the Medical Physics Expert MPE?
Specialist - external (Falls under the IRMER)
Give advice on the matters of radiation protection concerning medical and non-medical exposures, including the measurement and optimisation of patient doses and QA.
Who is the radiation protection supervisor RPS?
Senior dentist or DCP (post qaul in radiography)- interal
Assess risks and ensure precautions are taken to minimise them.
IRR17
What is the legal person responsible for?
Organising a 3 yearly assessment of radiation safety within the workplace.
Drawing up the local rules - referred to by all staff
Where should the local rules be located?
At each X-ray machine
A copy in the radiation protection file
Safety zone - 2m
Controlled area -1.5m
What is the usual dose investigation level?
Anything above 1 mSv per year
What must the Radiation protection supervisor hold to be a RPS?
Certificate of competence
Recognised by the HSE
Who is the referrer of dental radiographs?
The dentists
IRMER practitioner…
The dentist or radiographer (therapists) who takes responsibility for JUSTIFYING the taking of the radiograph.
Operator…
Any member of the dental team who carries out all or part of the practical duties involved with exposure or processing.
Can therapists be an IRMER practitioner in the hospital?
NO
What patient should not be exposed to radiation?
Pregnant patient
What to do during accidental exposure/machine malfunction?
Turn off the main power source.
What must be done if a practice decides not to carry out non-medical imaging exposures?
Written protocol
Who must be notified in the event of an accidental exposure occurrence?
RPA
The 2 examples of types equipment testing:
- Acceptance Testing- new dental imaging
- Routine survey - existing equipment
What is the radiation protection file?
Holds information regarding everything in place to ensure radiation protection within the workplace.
What is the time frame for updating the radiation protection file?
Yearly
What is the purpose of a Quality assurance system?
Ensure images are always at a high standard
Reducing exposure time and faults (handling, during exposure, processing)
What is the radiography QA scoring system set out in clinical governance guidelines?
Grade 1 - Excellent 70%
Grade 2- Diagnostically acceptable 20%
Grade 3- Unacceptable 10%
How often should the results of the QA scoring system be recorded and why do they need to be recorded?
After each exposure
Analysed on a regular basis and any problems identified ASAP
See if there is a pattern in each surgery or machine malfunctions
Who is at high risk of exposure in the dental workplace?
The operator
If a QA score 3 is a regular occurrence what is the next step?
Reject image analysis sheet
How often should radiation equipment be checked?
3 yearly
What is the percentage of reduction in scatter radiation when fast films, shortest exposure and narrowest beam are combined?
40%
What should a parent wear if the child cannot keep still during an X-RAY?
Protective lead apron
How can the amount of stray radiation received by staff be checked?
Film badge worn for 3 months at waist level
Suppliers + Processors- Radiation protection division (RPD)
How often should a low risk patient be radiographed?
Every 2 years
How often should a Moderate risk patient be radiographed?
Every Year
How often should a High risk patient be radiographed?
Every 6 months - reducing when caries risk is under control
What are intra-oral films?
Image taken within the oral cavity
What are extra-oral films?
Image taken outside the oral cavity
Contents of an intra-oral film packet….
Paper, film, paper, lead foil
What does a horizontal bitewing show and what does it detect?
The posterior teeth in occlusion - INTRA
Detect CARIES
What does a vertical bitewing show and what does it detect?
Extended view of the posterior teeth, from mid-root of both upper n lowers. - INTRA
Periodontal bone levels, true periodontal pockets.
What does a periapical radiograph show and what does it detect?
One or two teeth in full length with surrounding bone. - INTRA
Infection, mobility, fractures
What does an anterior occlusal radiograph show and what does it detect?
Plane view of the anterior section. - INTRA
To check for un-erupted teeth, supernumerary teeth and cysts.
Contents of an extra-oral film cassette….
Cassette case
Intensifying screen
coating
film
coating
intensifying screen
cassette case
True or False: the packets of extra-oral films can only be opened in a dark room?
True
What does a Dental Panoramic Tomograph DPT + OPG show and what is the purpose?
Shows both jaws and their surrounding bone anatomy. - EXTRA
Ortho, wisdom teeth, helps diagnose pathology, jaw fractures.
What does a lateral oblique show and what is it to check?
Shows the posterior portion of one side of the mandible including the ramus. - EXTRA
Check the position of un-erupted third molars
What does a lateral skull (cephalometric) show and what does it check?
View of the side of the head. -EXTRA
Taken in a machine called “Cephalostat”
Monitor Jaw growth, check malocclusion for severe Ortho purposes.
Intra oral films are held in place by…
Film holders
Intra oral digital films are held in place by….
Special sensor
What are the 2 angulations that intra-oral films can be exposed in?
1- paralleling technique - periapical
2. bisecting angle technique - anterior occlusal
What does digital radiography avoid the use of?
chemically coated plastic film, and the need for processing.
The sensor plate on digital radiographs is connected directly to the computer via USB cable. Uses pixels
Advantages of digital radiography…
- Financial savings
- Avoids health and safety issues from occurring
- Helps to achieve ALARP due to low dose
- Image is produced quickly
- same sensor can be used repeatedly
Disadvantages of digital radiography…
- Inadequate infection control
- Financial implications
- Unable to alter image
What is a hidden image called?
Latent image
Intra-oral film packet contains…
Celluloid film coated with light sensitive silver bromide salts.
Example of an automatic processing machine:
Velopex machine
Automatic processing machine consists of:
Chemical and water tanks, conveyor belt style of rollers that carry the film through.
The order of automatic processing:
Developer, fixer, water, dry
How many tanks does an automatic processing machine use?
3 tanks
What is developer?
Alkaline - hazardous chemical waste
What is fixer?
Acid - hazardous chemical waste
Manual processing is carried out by hand in a dark room: True or False?
True
The water tank in manual processing is heated what is the temperature range?
18-22C
20c is the ideal temperature
What colour is the manual processing safety light?
Red
The order of manual processing:
developer
wash
fixer
wash
What are the deposits found in developing tanks called?
Silver bromide
What do you use when topping up the chemicals?
A Funnel
What does lead foil do?
Absorb scatters
How many tanks are present in manual processing?
4 tanks
Example of indirect digital..
Scanner
Example of direct digital…
USB port, wireless
What does mounting mean?
Changing the image to its correct position after processing.
what could happen if an image is not mounted correctly?
Wrong treatment could be done.
poorly maintained equipment will lead to…
poor quality radiographs
What is a common reason for x-ray films to deteriorate before expiry date?
If they are left in hot or damp places or kept too near an x-ray set
How should intra oral films be stored?
Laying Flat
Maintenance of processing machines:
cleaned daily
What fault is a dark film?
Processing fault
Overdeveloped/overexposed
What fault is a blank image?
Processing fault
Not been exposed to radiation
What is the fault of a foggy image?
Common fault
Film expired
What is the fault of a black film?
Processing
exposed to light
What is the fault of a light film?
processing
underexposed
what is the fault of a blurry film?
exposure
movement
what is the fault of foreshortening and elongation image?
exposure
incorrect cone positioning
What is the fault of brown and green marks on an image?
Handling
split chemicals
what is the fault of black lines across the film?
handing
bent film
Faults are avoidable due to maintenance
Universal system of quality…
scoring and analysing radiographs.
What test is preformed for x-ray machines?
Step wedge test
What does the step wedge test do?
Determine the strength of the solution ( developer)
