what is a radiograph?
an image produced by x-rays passing through an object and interacting the the photographic emulsion on a film.
why are radiographs useful?
they allow us to look inside the body, particularly at the mineralised tissues. Other advanced techinques allow us to look at soft tissue aswell.
what dose is from a panoramic? and how many days does it last?
- 4-30 microSv
- 1-3 days
what dose from a periapical? and over how many hours/days?
- 1-8.3 microSv
- 8-40 hrs
how many intra oral examinations are taken each year roughly?
over 10 million
how many panoramic x-rays are taken each year roughly?
over 3 million
what does the term ‘somatic’ mean?
-affecting those iradiated
do deterministic effects of radiation occur in dentistry?
- No
- only non-deterministic effects occur
what does ALARP stand for?
As Low As Reasonably Possible
what are some warnigng signs that a radiograph is about to be taken?
- visible light and audible noise when x-rays produced
- operator should be able to prevent access to controlled area
- control panels/switches are outside the control area
why might a peri-apical be taken?
- detect apical inflammation
- assess perio problems
- trauma/fractures
- tooth morphology pre-extraction
- presence/position of unerupted teeth
- endodontics
- pre/post apical surgery
- eruption of implants
what are the two techniques of taking a periapical?
- paralleling
- bisected angle
name 4 different image receptors
- direct film
- indirect film
- DR (CCD or CMOS)
- CR (PSP)
what receptor sizes are used for bitewings?
0,1,2
what receptor sizes are used for young children?
0,1
what receptor size for adults anterior are used?
1
what receptor size for adult posterior periapical is used?
2
what receptor size is used for occlusals?
4
how is human error reduced?
- introducing simpler systems
- improve working enviroment
- encourage reporting without blame
what are the two legislations for radiography
- IR(ME)R 200 -protects the pt
- IRR 99 -protects staff and public
is caries on a radiograph over or underestimated?
underestimated
what is the dose of exposure for a dental x-ray?
0.005mSv
what is the does of of exposure from 100g Brazil nuts?
-0.01mSv
