Intraoral radiography Flashcards
How do the voltage and the mAmps affect the number of X-rays?
kV affects penetration of X-rays
mAMPs affects the number of X-rays
What percentage of electrons in an X-ray tube are converted to X-rays?
1% of electrons are converted into photons
Good description of x-ray interaction with objects?
Objects are in the way of x-rays which means there is a shadow formed behind the object.
What is the peri-apical radiography technique?
Peri-apical literally means beyond the apex of the tooth
What are the things taht should be noted during image formation?
Crown of the tooth should be fully implemented
No distortion of the image should occur
What is the parallel technique used for?
It allows us to obtain the best image possible.
What is required for the parallel technique?
Parallel X-ray
Image receptor as close and parallel to the teeth
X-rays perpendicular aimed at image receptor
How should orientation of the plate be different between incisors/canines and the molars/premolars?
Incisors and canines: Long axis of the detector should be placed vertically.
Molars and premolars: Long axis of the detector should be placed horizontally.
Which plate size should be used for different teeth?
Incisors/canines: Size 1 plates
Molars/premolars: Size 2 plates
What are the image detectors used in the dental school called?
PhotoStimulable Phosphor Storage Plates (PSPP)
Why are PSPPs placed in a plastic envelope/barrier?
To avoid cross contamination
To avoid poisoning
To avoid light from erasing the latent image
How can damage to PSPPs be avoided?
Use proper cleaning agents
Never bend a PSPP
Tell patients not to bite on the plate
A piece of cardboard inside the plastic envelope may be useful to avoid bitemarks
How are image receptors held in the right place?
Using image receptor holding devices such as the Rinn set which uses a firm grip to hold image receptor and provides a good aiming aid for the X-ray machine to be positioned correctly.
Why are bitewing radiographs taken?
They allow one to assess interproximal decay as well as interproximal bone height.
How are bitewings modified to assess patients with severe periodontitis?
The image receptor is arranged vertically rather than horizontally.
This allows a better view and assessment of the actual vertical bone loss.
Patients with second permanent molars erupted require 2 bitewings from each side.
How are bitewing images taken?
With parallel technique since this is the only way to aim perpendicular at the image receptor and through the contact points/interproximal surfaces.
How should the orientation marker be oritentated for periapical radiographs?
Should be projected superior of the crown of the tooth. If one uses PSPP upside down, the marker will be projected on top of a root, apex or its vicinity.
Where should the orientation marker be for bitewings?
Always in corner of image projected on or near a root.
What is the orientation marker?
The little ‘a’ on PSPPs
How should radiographs be looked at?
Mount radiographs as if you would look at the patient.
