Dental Radiography Module 10

Question 1

Cone Beam Computed Tomography -CBCT compared to other xrays is…?

Answer 1

5 times the radiated dose

Question 2

CBCT scanners should be able to read the image at what grayscales and shades…?

Answer 2

Present-day scanners render images in 14-bit grayscale, providing 16,384 shades.

Question 3

CBCT scans are used for what…?

Answer 3

Small approx. 4cm³ –unerupted teeth,impacted teeth, cleft palate, investigations into inferior dental canal position, implant positioning, endodontic treatment complications, root fracture
•
Mediumapprox.8cm³–cleft palate, Orthognathic surgery, implantpositioning, lesions, fractures,tumors
•
Large –Orthognathic surgery, implant positioning, lesions, fractures,tumors

Question 4

CBCT scans….?

Answer 4

Exposure factor between 60-120kV
•
Range of 1-20 mA
•
Scan takes between 5-40seconds
•
May use a pulsedbeam
•
Minimise soft tissueabsorption
•
Scan lasts 20 seconds patient is therefore exposed to 3.5 seconds of ionizingradiation
•
Effective dose differs greatly dependenton
•
Exposure factors kV, mA and time ofexposure
•
The volume size –field ofview
•
The equipmentused
•
The area beingimaged
Pt must stay still

Question 5

what is the Brånemark System…?

Answer 5

Can be done ineither
•
Two stages-implant placed then left for 3-6 months (healing period) then abutmentplaced
or
•
One stage –non submerged –implant loadedimmediately
–notideal