Dental Radiography

Question 1

Types of X-Ray Receptors

Answer 1

Traditional Film
Phosphor Storage Plates (PSP)
Direct Digital

Question 2

What are the parts of a Traditional Film packet?

Answer 2

1. Outer Plastic/ Vinyl/ Paper wrapping (protects film from saliva)
2. Black Paper wrapping (protects emiulsion)
3. X-ray film (sensitive component)
4. Lead foil/ sheet ( prevents backscattering of radiation reduces patient exposure)

Question 3

What way does the film go in the mouth?

Answer 3

The coloured side goes toward the teeth and the white part is facing the cheek

White in sight and Dot in slot

Question 4

Film Base

Answer 4

Polyester plastic, provides support and strength

Question 5

Adhesive Layer

Answer 5

Attaches emulsion to base

Question 6

Film Emulsion

Answer 6

A mixture of gelatin and silver halide
crystals (sensitive to radiation)

Question 7

Protective Layer

Answer 7

protects emulsion from damage.

Question 8

Intra Oral

Answer 8

Placed inside the mouth

Question 9

Extra Oral

Answer 9

Taken on the outside of the mouth

Question 10

Duplicating

Answer 10

Produces two copies of the same image
(special film)

Question 11

What is a Latent image?

Answer 11

A latent image is a fil that has been exposed to radiation but has not been deveopled yet

Question 12

what are the different film speeds

Answer 12

ratings from A-F
D,E,F are only film used for intraoral radiology

Question 13

Screen

Answer 13

Film placed between 2 intensifying screens for exposure

Question 14

Non-screen

Answer 14

Film is exposed directly to x-rays, requires longer
exposure time, NOT recommended for use in
dentistry.

Question 15

Film Storage

Answer 15

Film must be kept in a cool, dry place
* Must be stored in an area adequately shielded
from radiation
* Film MUST be used before expiration date
(can cause fogged films)

Question 16

Digital Radiography

Answer 16

Digital imaging eliminates chemical processing and
hazardous wastes (lead foil, chemicals)
* Requires LESS Radiation to expose
* Allows for digital enhancements, measurements and
corrections
* Images can be electronically transferred to other
health care providers
* Sensors are VERY expensive

Question 17

Phosphor Storage Imaging (PSP)

Answer 17

• Thin, flexible plate that is covered in phosphor crystals
• Plates are the same size as conventional x-ray film
• Phosphor layer stores energy of x-ray photons
• After exposure plates are placed into a scanner
• Scanner laser reads the latent image and converts it to a digital image
• Films are exposed to a bright light to ”erase” the image

Question 18

Intraoral Radiography

Periapical (PA)

Answer 18

Used to view entire tooth (root and crown) Size#2 are used for posterior and Size #1 for Anterior.

Question 19

Intraoral Radiography

Interproximal
(BWS)

Answer 19

Used to detect interproximal (between the teeth) caries and bone loss. Can be taken vertically and horizontally.

Question 20

Intraoral Radiography

Occlusal

Answer 20

Used to determine tooth development, can determine if patients are missing teeth. The film is placed in the mouth horizontally and the patient down bites on the film like a cookie.

Question 21

Producing Diagnostically Acceptable
Radiographs

Answer 21

1. All required anatomy must be present.
2. Contrast also referred to as grey scale.
3. Density also referred to as darkness.
4. Sharpness.
5. Magnification.
6. Distortion.

Question 22

The Paralleling Technique

Answer 22

• Receptor is parallel to long axis of tooth
• X-ray beam is perpendicular to the long axis of the tooth
• Face of cone is parallel with the face of the film.
• Common errors: incorrect placement and alignment.

Question 23

Paralleling Technique Steps

Answer 23

1. Explain procedure to the patient.
2. Position receptor close to midline for a maxillary PA and between the tongue and teeth for a mandibular exposure.
3. Position receptor centered on the required anatomy/teeth.
4. Position receptor parallel to the long axis of the teeth.
5. Seat bite block on the incisal edge or occlusal surface for support.
6. Ask patient to relax and slowly close down to support the XCP holder, and breath slowly through their nose.