Topic 4: Dental Radiology Techniques Flashcards
What are the indications for taking dental radiographs
Before and after extractions Periodontal disease Discolored teeth Fractured teeth Gingival ulcers Missing teeth (Evaluate an area where the teeth appear to be missing) Malocclusions causing trauma Malformed teeth Tooth resorptions or root resorptions Pet dropping food Foul odor in mouth Reluctance to eat Reluctance to eat chews Nasal discharge
What are the medical indications for taking dental radiographs
To document the obvious - supporting treatment decisions
Preoperative, intraoperative, and postoperative endodontics
Endodontics: dental speciality concerned with the study & tx of dental pulp
Follow progression of pulpal pathology and/or periodontal disease
What are the legal indications for dental radiographs
Part of the file/ Legal documentation
For client communication
For prepurchase exams on show dogs to see if the proper number of teeth exist
What are the practice management/economical reasons for doing dental radiographs
Dental radiology pays for the expensive “toys” that don’t pay for themselves…
…” Or “ we are losing money by not taking intraoral x-rays!“
Because it is a diagnostic tool
We found lesions – we treat them!
Describe the dental X-ray machine
Provides the X-ray source Portable or wall-mounted Portable Floor trolley (less user friendly Hand-held dental x-ray unit KVp and MA settings are fixed Usually 50-70 KVp mA is fixed (8-10) Can use regular rad machine, but film-focus distance is only 30-50 cm Better to use dental machine
What is the one exposure variable for the dental X-ray machine
time in seconds
What are two types of dental radiology
dental standard radiology
digital dental radiology
What are the two types of digital dental radiology
indirect (CR)
direct (DR)
Describe dental film
Small & flexible Non-screen film Size 0, 1, 2 (periapical), size 4 (occlusal) Non screen film Single emulsion Speed: D (ultra) E, F(EKTA) E, F: lower detail D: commonly used
Why is the dental film in an envelope
to protect it from light exposure
why does the dental film contain a layer of lead foil
to absorb scatter radiation
Why does the dental film have a dot
to let you know which side is to be placed rostrally. So you can always tell right from left
How do you develop X-ray films
Chairside darkroom
Developing solutions
Film clips
Describe indirect dental radiology
Use photo-stimulable phosphorplates (PSP)
Place in plastic holders
Exposed and then digitally scanned
Flexible, reusable plates or sheets instead of film
After exposure, plate→ scanner → latent formed image is retrieved point-by-point → digitized (laser light scanning)
The digitized images are stored and displayed on a computer screen.
What are the advantages to the indirect digital dental radiographs
Sensor plates size 0,2, 4, (6)
Flexible
Long used-life
Not expensive to replace
what are the disadvantages to indirect digital dental radiographs
Sensor plates must be removed from mouth to get the image
More time than direct
Image quality questionable
Keep away from direct light while scanning
Describe direct digital dental radiography
Sensor (CCD-Type or CMOS)
2 sizes (1 & 2)
Rigid, relatively thick
Connect to a computer with appropriate software (by wire or WIFI)
What are the advantages to direct digital dental radiology
FAST!
Do not have to remove sensor to get the image
Better quality image
what are the disadvantages to direct digital dental radiology
Disadvantages: Small sensor size Difficult to fit into small mouths Fragile! Expensive Only the sensor 8000$ (2012)
What are the methods for radiology safety for dental xrays
Proper tube angle is important
Distance from the tube: 6 ft
Apron, thyroid lead protector
Dosimeter
What is the intra-oral dental X-ray technique
intra-oral techniques:
Film positioned inside the mouth
Describe the intra-oral dental X-ray technique
Patient can be left on lateral recumbency (as it is during the dental cleaning OR moved on dorsal or ventral recumbency
Describe the parallel technique
Film is placed parallel to the long axis of the tooth
Central beam is directed perpendicular to the film
What happens when the beam is angled too vertically when using the bisecting technique
foreshortened
what happens when the beam is angled too horizontally when using the bisecting technique
lengthened
How do you get the perfect image representation of the tooth using the bisecting technique
If the primary bean is aimed at 90 degree to a bisecting angle, the image will be a true representation of the tooth!
When you’re taking an X-ray of the front tooth (maximally and mandibular incisors and canines) using the bisecting technique
view the animal from the side
when you’re taking an X-ray of the side tooth (maxillary molars and premolars) using the bisecting technique
view the animal from the front
How do you take a picture of all three roots in one picture
the parallax effect
